Precision in Dental Esthetics PDF

I
IN DENTAL
ESTHETICS
CLINICAL AND LABORATORY PROCEDURES
ISBN 88-7492-011-3
€ 220,00 9 788874 920112

PRECISION
IN DENTAL
ESTHETICS
'fhi.. hook j, dedirall'd to 111� ..plt·ndid daugl11er. Sarah." ho ha., tnadl' 111� lifl'
nH·aniugful. and to 111� part'llh. \ !0 an• n·,polhihlt· fur all th:11 j., �ood in IIH'.
IJoiiU'IIiro .lla.'.iiroui
T'hi, l,ook j, dedicmed to 111� l':llnil�. tl w �OIIIT(' of lo\f' and hapl'illt'"' tlwt
gi\t·� IIH' rru•r-� and ,('fllrit� in all tiling..
/(omNJ Pust·rllfl DOMENICO MASSIRONI, MD, DMD

Private Practice, Milan, Italy
'Thi .. hook j, d(·dirml'd to all 111� dt·are,l. wond('rful frit·rHI ..-111� part'lth.
inrluding my fath('r. Sih io. ''Ito left 11, all too ,ooiL uncl111� n1olitt·r. Ho ..alha.
"ho j., happy for nw wda�. and 111� cltildren. Chri ..tian nnd Cahrit·li·. '' ho
hring j o� to 111� lifl'. To thi, li.t I arid m� hr1hrr. Bol,eno. and 111� ,j,JfT. ROMEO PASCETA, MDT
�Iarina. who are nnill'd id1 \,� llu· I<J\-ing hond of dw famil�.
Dental Laboratory Technician and Owner, Chieti, Italy
\ lh
Gillsl•ppe Jloltii'O
GIUSEPPE ROMEO, MDT
Dental Laboratory Technician and Owner, Turin, Italy
Quintessenza Edizioni Sri

Milan, Chicago, Berlin, Tokyo, London, Paris, Barcelona,
Istanbul, Sao Paulo, Mumbai, Moscow, Prague, and Warsaw

PRECISION
IN DENTAL
ESTHETICS
'fhi.. hook j, dedirall'd to 111� ..plt·ndid daugl11er. Sarah." ho ha., tnadl' 111� lifl'
nH·aniugful. and to 111� part'llh. \ !0 an• n·,polhihlt· fur all th:11 j., �ood in IIH'.
IJoiiU'IIiro .lla.'.iiroui
T'hi, l,ook j, dedicmed to 111� l':llnil�. tl w �OIIIT(' of lo\f' and hapl'illt'"' tlwt
gi\t·� IIH' rru•r-� and ,('fllrit� in all tiling..
/(omNJ Pust·rllfl DOMENICO MASSIRONI, MD, DMD

Private Practice, Milan, Italy
'Thi .. hook j, d(·dirml'd to all 111� dt·are,l. wond('rful frit·rHI ..-111� part'lth.
inrluding my fath('r. Sih io. ''Ito left 11, all too ,ooiL uncl111� n1olitt·r. Ho ..alha.
"ho j., happy for nw wda�. and 111� cltildren. Chri ..tian nnd Cahrit·li·. '' ho
hring j o� to 111� lifl'. To thi, li.t I arid m� hr1hrr. Bol,eno. and 111� ,j,JfT. ROMEO PASCETA, MDT
�Iarina. who are nnill'd id1 \,� llu· I<J\-ing hond of dw famil�.
Dental Laboratory Technician and Owner, Chieti, Italy
\ lh
Gillsl•ppe Jloltii'O
GIUSEPPE ROMEO, MDT
Dental Laboratory Technician and Owner, Turin, Italy

Milan, Chicago, Berlin, Tokyo, London, Paris, Barcelona,
Istanbul, Sao Paulo, Mumbai, Moscow, Prague, and Warsaw

TABLE OF CONTENTS
First published in Italian in 2004 by Quintessenza Edizioni Sri, Milan.
Estetica e precisione: Procedure cliniche e di laboratorio
A OU Tf . ALff OR
v) p t
T l T 1
ldndg re • TrectmP 1' }I n
1
with the Pros,r.tic Tea 1
fo
Pr st 1 p l r 'IOnS
, c t 1� w•t t P : tf
0 lr n lt r 1'
Magri"iC1' on SysteM> Used 11 )en• s•ny
2
Types o lld' y 1r- t s• ru t <
Phys1o,gic 'T<cts and llSt umH • tn•er dllC'
©2007 Quintessenza Edizioni Sri
20017 Passirana di Rho (MI)

Tooth Preparation for Complete Crowls
via Ciro Menotti, 65
3
Italy Anatol" r liMitS
E-mail: info@quintessenzaedizioni.it
, IErtlfl r lr r1p �
www.quintessenzaedizioni.it
R >tali � lllStrL mer ·s
System at 1ed tooth prepdrat un

PAGE 84
,(IPctiVC oncentration
Editors of the English Edition: Lisa C. Bywaters and Bryn Goates
Finish Line Destgns for Cotrple't Crown
4
All rights reserved. This book or any part thereof
may not be reproduced, stored in a Preparattons
retrieval system, or transmitted in any form or by
any means, electronic, mechanical,
photocopymg, or otherw1se, without prior written (haraC(E IS II< S Of hE V1 IOUS fin I 1'
permission of the publisher.
Additional . t n dd tnes •or toot! n pa 1 '
Printed in Italy
PAhE lDB
TABLE OF CONTENTS
First published in Italian in 2004 by Quintessenza Edizioni Sri, Milan.
Estetica e precisione: Procedure cliniche e di laboratorio
A OU Tf . ALff OR
v) p t
T l T 1
ldndg re • TrectmP 1' }I n
1
with the Pros,r.tic Tea 1
fo
Pr st 1 p l r 'IOnS
, c t 1� w•t t P : tf
0 lr n lt r 1'
Magri"iC1' on SysteM> Used 11 )en• s•ny
2
Types o lld' y 1r- t s• ru t <
Phys1o,gic 'T<cts and llSt umH • tn•er dllC'
©2007 Quintessenza Edizioni Sri
20017 Passirana di Rho (MI)

Tooth Preparation for Complete Crowls
via Ciro Menotti, 65
3
Italy Anatol" r liMitS
E-mail: info@quintessenzaedizioni.it
, IErtlfl r lr r1p �
www.quintessenzaedizioni.it
R >tali � lllStrL mer ·s
System at 1ed tooth prepdrat un

PAGE 84
,(IPctiVC oncentration
Editors of the English Edition: Lisa C. Bywaters and Bryn Goates
Finish Line Destgns for Cotrple't Crown
4
All rights reserved. This book or any part thereof
may not be reproduced, stored in a Preparattons
retrieval system, or transmitted in any form or by
any means, electronic, mechanical,
photocopymg, or otherw1se, without prior written (haraC(E IS II< S Of hE V1 IOUS fin I 1'
permission of the publisher.
Additional . t n dd tnes •or toot! n pa 1 '
Printed in Italy
PAhE lDB
oc d r:
5 1
, 1 Const e tlo 1. for Soft ts. C er r c 11 P osthPt c Restoraticfl
6
RPtrac• o
mm1r st rd'IO
11 ld gm
C tntc I . O'lSidH !'tor> or Pr)Vts on I
7
ProctlP;';
Estr.ttc Co ;tde•attols fo• Cerarric
•er t c
12
cat o R >torat10ns
Pr 1 ed� e f pr •or ,11
, or
1n1 1 con dt 11
St•dt i tiD ''C lniQUE
c nc • or1 w1tr he prov 1
E •est a d 'ldl c ec
TEc'l'l cal Corsiderat ons for Proviston
8
Prostheses Ce1e1ta• on
3
l1 gn st c rcVI' > 11 '� ts
y e en•
ilr li r o)ierT' d SO IL 'Ions

Custo n Impression Trays and Imp ess1or lm1< 11 � c e
9
Mlt'na s t n (IV' res o r 'len•
' s y
er f1
I�DEX
oc d r:
5 1
, 1 Const e tlo 1. for Soft ts. C er r c 11 P osthPt c Restoraticfl
6
RPtrac• o
mm1r st rd'IO
11 ld gm
C tntc I . O'lSidH !'tor> or Pr)Vts on I
7
ProctlP;';
Estr.ttc Co ;tde•attols fo• Cerarric
•er t c
12
cat o R >torat10ns
Pr 1 ed� e f pr •or ,11
, or
1n1 1 con dt 11
St•dt i tiD ''C lniQUE
c nc • or1 w1tr he prov 1
E •est a d 'ldl c ec
TEc'l'l cal Corsiderat ons for Proviston
8
Prostheses Ce1e1ta• on
3
l1 gn st c rcVI' > 11 '� ts
y e en•
ilr li r o)ierT' d SO IL 'Ions

Custo n Impression Trays and Imp ess1or lm1< 11 � c e
9
Mlt'na s t n (IV' res o r 'len•
' s y
er f1
I�DEX
ABOUT THE AUTHORS
Romeo Pasceta, MDT, earned his diploma as a dental technician in 1977. He cur-
rently owns a dental laboratory in Chieti, Italy, where he specializes in fabricating con
ventional and implant-supported fixed prosthodontics using a stereomicroscope. A
diplomate of the International Congress of Oral lmplantologists since 1998, Mr Pascetta
lectures on the subject of precision and esthetics in Italy and abroad and has held a vis
iting professorship at the G D'Annunzio University in Chieti, Italy, since 2000, teaching
the dental prosthesis finishing course. He has published numerous articles, two mono
graphs on ixed prosthodontics (with Drs Mario Semenza and Carlo Semenza), and a book,
La Precisione nela restaurazione protesica (Precision in Prosthetic Restorative Treatment;
Quintessenza, 1993) with Dr Domenico Massironi and Alberto Battistelli.
Giuseppe Romeo, MDT, had esthetic specialization at Geneve after completing his
academic training in Italy and abroad while practicing in the United States and
(let to righ) Romeo Pascetta. Domenico Massironi. and Giuseppe Romeo. Switzerland. He owns a dental laboratory in Turin, Italy, and focuses primarily on ixed
prosthodontics and esthetic restorations. Mr Romeo presents at conferences and seminars
organized nationally and abroad and has published many articles in prestigious national
and international journals. He is a member of the Oral Design Foundation, and the italian
group for dental technologies culture, council member and President elected of European
Domenico Massironi, MD, DMD, earned a degree in medicine and surgery at Pavia Academy of Dental Technologies.
University in Pavia, Italy, before specializing in odontostomatology. Since 1988, using the
stereomicroscope, he focuses on prosthodontics and implant dentistry in his multidisci
plinary practice in Melegnano (Italy). Dr Massironi is the author of numerous journal arti
cles and co-author, with Romeo Pascetta and Alberto Battistelli, of the atlas text La
Precisione nela restaurazione protesica (Precision in Prosthetic Restorative Treatment;
Quintessenza, 1993). He has presented numerous seminars and symposia in prestigious
national and international venues and is an active member of the European Academy of
Esthetic Dentisty as well as a diplomate of the International Congress of Oral
lmplantologists.
ABOUT THE AUTHORS
Romeo Pasceta, MDT, earned his diploma as a dental technician in 1977. He cur-
rently owns a dental laboratory in Chieti, Italy, where he specializes in fabricating con
ventional and implant-supported fixed prosthodontics using a stereomicroscope. A
diplomate of the International Congress of Oral lmplantologists since 1998, Mr Pascetta
lectures on the subject of precision and esthetics in Italy and abroad and has held a vis
iting professorship at the G D'Annunzio University in Chieti, Italy, since 2000, teaching
the dental prosthesis finishing course. He has published numerous articles, two mono
graphs on ixed prosthodontics (with Drs Mario Semenza and Carlo Semenza), and a book,
La Precisione nela restaurazione protesica (Precision in Prosthetic Restorative Treatment;
Quintessenza, 1993) with Dr Domenico Massironi and Alberto Battistelli.
Giuseppe Romeo, MDT, had esthetic specialization at Geneve after completing his
academic training in Italy and abroad while practicing in the United States and
(let to righ) Romeo Pascetta. Domenico Massironi. and Giuseppe Romeo. Switzerland. He owns a dental laboratory in Turin, Italy, and focuses primarily on ixed
prosthodontics and esthetic restorations. Mr Romeo presents at conferences and seminars
organized nationally and abroad and has published many articles in prestigious national
and international journals. He is a member of the Oral Design Foundation, and the italian
group for dental technologies culture, council member and President elected of European
Domenico Massironi, MD, DMD, earned a degree in medicine and surgery at Pavia Academy of Dental Technologies.
University in Pavia, Italy, before specializing in odontostomatology. Since 1988, using the
stereomicroscope, he focuses on prosthodontics and implant dentistry in his multidisci
plinary practice in Melegnano (Italy). Dr Massironi is the author of numerous journal arti
cles and co-author, with Romeo Pascetta and Alberto Battistelli, of the atlas text La
Precisione nela restaurazione protesica (Precision in Prosthetic Restorative Treatment;
Quintessenza, 1993). He has presented numerous seminars and symposia in prestigious
national and international venues and is an active member of the European Academy of
Esthetic Dentisty as well as a diplomate of the International Congress of Oral
lmplantologists.
F 0 R E w 0 R D
W
hen this work first appeared in Italian as a two-volume set, the cover design
gave the impression that the text would describe d i fferent magnification
systems used i n dentistry. However, the authors - a clinician and two dental
technicians - have created a unique work that sets new standards of precision and per
formance in restorative dentistry. Every area of restoration is described i n detail and illus
trated with images of the highest quality.
The authors start with the initial patient examination and continue to document each
clinical and laboratory step needed for precise fixed restorations. The excellent clinical
chapters detail procedures such as refining the preparation margin, impression taking,
fabricating master casts, creating provisional restorations, and cementation. The text cov
ers laboratoy procedures, including the creation of a diagnostic waxup and casting and
veneering of the definitive framework for ceramometal restorations. The authors demon
strate their own unique way of performing each procedure, and the definitive results
are so convincing that one can have no objections to their approach. Finally, the exten
sive literature review at the end of each chapter includes many English- and German-lan
guage articles on each topic, attesting to the internationality of this masterpiece.
Every clinician and dental technician who is interested in improving prosthetic precision
should acquire this book. Even more importantly, students of dental medicine and of den
tal technology should use this book to learn the importance of quality i n our profession.
I wish the authors great success with this book and hope that the English edition will
become as widely read as the original Italian volumes.
Professor Dr Peter Scharer, DMD, MS*

Dean
School of Dental Medicine
University of Zurich
Zurich, Switzerland
·written prior to Professor Schirer's death in December 2004.
i
F 0 R E w 0 R D
W
hen this work first appeared in Italian as a two-volume set, the cover design
gave the impression that the text would describe d i fferent magnification
systems used i n dentistry. However, the authors - a clinician and two dental
technicians - have created a unique work that sets new standards of precision and per
formance in restorative dentistry. Every area of restoration is described i n detail and illus
trated with images of the highest quality.
The authors start with the initial patient examination and continue to document each
clinical and laboratory step needed for precise fixed restorations. The excellent clinical
chapters detail procedures such as refining the preparation margin, impression taking,
fabricating master casts, creating provisional restorations, and cementation. The text cov
ers laboratoy procedures, including the creation of a diagnostic waxup and casting and
veneering of the definitive framework for ceramometal restorations. The authors demon
strate their own unique way of performing each procedure, and the definitive results
are so convincing that one can have no objections to their approach. Finally, the exten
sive literature review at the end of each chapter includes many English- and German-lan
guage articles on each topic, attesting to the internationality of this masterpiece.
Every clinician and dental technician who is interested in improving prosthetic precision
should acquire this book. Even more importantly, students of dental medicine and of den
tal technology should use this book to learn the importance of quality i n our profession.
I wish the authors great success with this book and hope that the English edition will
become as widely read as the original Italian volumes.
Professor Dr Peter Scharer, DMD, MS*

Dean
School of Dental Medicine
University of Zurich
Zurich, Switzerland
·written prior to Professor Schirer's death in December 2004.
i
p R E F A c E
T
oday, clinicians find themselves predominantly treating cases in which esthetics cementation. It also guides the reader in selecting the most appropriate procedures
and function are of equal importance. ProsthodontiC restoration, whether Simple based on the prosthetic design and the correct use of the various types of cement. This
or complex, encompasses numerous phases and procedures throughout which the chapter was prepared with the collaboration of Dr Federico Ferraris, who helped shape
clinician and dental technician must work with precision to achieve the planned result. it into a true compendium on cements, clarifying their distinctive characteristics and the
The importance of the diagnostic treatment plan cannot be overstated; the clinician's indications for their use. The chapter is an invaluable reference for determining the type
accurate interpretation of the patient's goals is the most important factor in satisfying of material to be used in different clinical situations.
ever-increasing patient expectations. Moreover, meeting esthetic demands presented by The chapters on laboratory procedures related to prosthodontic treatment are written
these cases requires a serious on-going commitment from the prosthodontic team. by two dental technicians, each focusing on a diferent aspect of dental technology in
Clinicians and dental technicians must stay informed, in terms of both procedures and keeping with their natural predisposition and professional knowledge and experience.
scientific principles, in order to effectively select and use materials and methods best The practical information in these chapters can be readily applied by dental technicians.
suited to individual treatment plans. Romeo Pascetta contributed the chapters relating to accuracy with metal and ceramic
The objective of this publication is to provide valuable information to support the materials, focusing in particular on cast ceramics and the latest CAD/CAM systems using
prosthodontic team in the treatment of the various clinical cases and situations encoun innovative materials such as zirconium or alumina. Giuseppe Romeo is the author of the
tered in daily practice. This book contains a detailed analysis of the most significant clin technical sections related to the esthetic implementation o f prosthetic restoration,
ical prosthodontic procedures (eg, tooth preparation, finish line design, soft tissue emphasizing the diagnostic waxup, communication with the patient and the clinician,
retraction}, based on scientific evidence and presented in a practical framework to pro and preparing all-ceramic restorations.
vide useful treatment guidelines. It also describes the essential steps involved in man Our main objective in this book is to present high-quality, illustrative images and clin·
aging the restorative treatment, beginning with the clinical diagnosis and subsequent ical cases that represent a practical point of reference and consultation for the clinician
diagnostic waxup, then progressing to the correct use of provisional restorations, which and the dental technician. It is with great pride and gratification that we present this
are fundamental in the conditioning and correct development of the soft tissues, as well work as a representation of our knowledge and daily practice, based on the experience
as in the achievement of the functional and esthetic objectives. gained over 18 years in the routine use of the stereomicroscope. It is our sincere hope
The chapter on cementation presents a detailed analysis of the physical and rheo that its publication will benefit clinicians, dental technicians, and patients worldwide.
logical characteristics of cements and the various types of adhesive and conventional
Domenico Jllassironi
iil
p R E F A c E
T
oday, clinicians find themselves predominantly treating cases in which esthetics cementation. It also guides the reader in selecting the most appropriate procedures
and function are of equal importance. ProsthodontiC restoration, whether Simple based on the prosthetic design and the correct use of the various types of cement. This
or complex, encompasses numerous phases and procedures throughout which the chapter was prepared with the collaboration of Dr Federico Ferraris, who helped shape
clinician and dental technician must work with precision to achieve the planned result. it into a true compendium on cements, clarifying their distinctive characteristics and the
The importance of the diagnostic treatment plan cannot be overstated; the clinician's indications for their use. The chapter is an invaluable reference for determining the type
accurate interpretation of the patient's goals is the most important factor in satisfying of material to be used in different clinical situations.
ever-increasing patient expectations. Moreover, meeting esthetic demands presented by The chapters on laboratory procedures related to prosthodontic treatment are written
these cases requires a serious on-going commitment from the prosthodontic team. by two dental technicians, each focusing on a diferent aspect of dental technology in
Clinicians and dental technicians must stay informed, in terms of both procedures and keeping with their natural predisposition and professional knowledge and experience.
scientific principles, in order to effectively select and use materials and methods best The practical information in these chapters can be readily applied by dental technicians.
suited to individual treatment plans. Romeo Pascetta contributed the chapters relating to accuracy with metal and ceramic
The objective of this publication is to provide valuable information to support the materials, focusing in particular on cast ceramics and the latest CAD/CAM systems using
prosthodontic team in the treatment of the various clinical cases and situations encoun innovative materials such as zirconium or alumina. Giuseppe Romeo is the author of the
tered in daily practice. This book contains a detailed analysis of the most significant clin technical sections related to the esthetic implementation o f prosthetic restoration,
ical prosthodontic procedures (eg, tooth preparation, finish line design, soft tissue emphasizing the diagnostic waxup, communication with the patient and the clinician,
retraction}, based on scientific evidence and presented in a practical framework to pro and preparing all-ceramic restorations.
vide useful treatment guidelines. It also describes the essential steps involved in man Our main objective in this book is to present high-quality, illustrative images and clin·
aging the restorative treatment, beginning with the clinical diagnosis and subsequent ical cases that represent a practical point of reference and consultation for the clinician
diagnostic waxup, then progressing to the correct use of provisional restorations, which and the dental technician. It is with great pride and gratification that we present this
are fundamental in the conditioning and correct development of the soft tissues, as well work as a representation of our knowledge and daily practice, based on the experience
as in the achievement of the functional and esthetic objectives. gained over 18 years in the routine use of the stereomicroscope. It is our sincere hope
The chapter on cementation presents a detailed analysis of the physical and rheo that its publication will benefit clinicians, dental technicians, and patients worldwide.
logical characteristics of cements and the various types of adhesive and conventional
Domenico Jllassironi
iil
Thanks also to Dr Susanna Cottica for her constant support and correction of the
ACK OWLE DGME s manuscript.

My gratitude to Dr Paolo Trisi of Pescara, Italy, for the histological preparations of
cross-sections embedded in resin and photographed under magnification using polar·
ized light.
Thanks to the doctors with whom I collaborate in my practice, for their support,
friendship, and unflagging professional input: Alessandro Vanetti, Patrizia Oggioni, and
Pietro Fusari.
Special thanks to Dr Mario Vigoni for his assistance in researching the bibliography
This book would not have been completed without the help and
of scientific studies.
dedication of numerous collaborators, whose active participation Particular thanks for editing to the staf of Quintessence Publishing USA and to Cristina
and genuine commitment arose purely out of friendship and a Reina of Quintessence Publishing, Italy, and Dr Cristian Coraini.
devotion to the highest clinical and technical standards My gratitude to dental technicians Emilio Parmigiani and Marco Ferrario for their help
of dentistry. and collaboration in some of the dental technology sections.

Special thanks to my sister, Anna Massironi, for her participation in and support of
With the greatest pleasure, we devote a small space to recognize my didactic and scientific activities.
the names and contributions of all who have so generously Thanks are also due to my collaborators at the Gandini-Massironi dental offices: Sara
given their time and efort and let an indelible mark in our Scaiola, Mirella Ferri, Maria Rosa Farina, Cristina Colombi, Emanuela Badaracco, for their
memories. We ofer our most heartfelt thanks to you all. unstinting efforts and continuing support.
Romeo Pasceta
Thanks to Federico Di Primio, a dental technician par excellence and my collaborator for
many years. His consistent and conscientious work contributes to the success of my
Domenico Massironi professional activities.
My sincerest gratitude to Romeo Pascetta and Giuseppe Romeo, who are my friends, col· My sincere gratitude goes to Dr Domenico Massironi, who was kind enough to include
laborators, and co-authors. They are, above all, extraordinarily skilled dental technicians me in this project, providing new stimuli to my work and enriching my professional and
who create the prosthetic restorations for my clinical practice. Also to the dental techni· personal development.
cian Alberto Battistelli who has, for years, shared my passion and pursuit for precision Special thanks to my wife, Dr Stefania De Deo, for her consummate patience and
in prosthetic restoration. Without their expertise and technical skills, 1 would not be able invaluable assistance i n compiling the manuscript, and to my sons, Stefano and Giulio,
to present the restorations featured throughout this text. for their encouragement and support.
Thanks also to Dr Federico Ferraris for his dedication and organizational skills that
were so helpful in preparing this text. Giuseppe Romeo
To Professor Paola Gandini of Orthognathodontics at the University of Pisa, my heatfelt My professional esteem and thanks go to Dr Domenico Massironi, for his day-to-day
thanks for the presentation of the clinical cases we treated jointly in the offices we share. collaboration and for having involved me in the development of this manuscript.
"
Thanks also to Dr Susanna Cottica for her constant support and correction of the
ACK OWLE DGME s manuscript.

My gratitude to Dr Paolo Trisi of Pescara, Italy, for the histological preparations of
cross-sections embedded in resin and photographed under magnification using polar·
ized light.
Thanks to the doctors with whom I collaborate in my practice, for their support,
friendship, and unflagging professional input: Alessandro Vanetti, Patrizia Oggioni, and
Pietro Fusari.
Special thanks to Dr Mario Vigoni for his assistance in researching the bibliography
This book would not have been completed without the help and
of scientific studies.
dedication of numerous collaborators, whose active participation Particular thanks for editing to the staf of Quintessence Publishing USA and to Cristina
and genuine commitment arose purely out of friendship and a Reina of Quintessence Publishing, Italy, and Dr Cristian Coraini.
devotion to the highest clinical and technical standards My gratitude to dental technicians Emilio Parmigiani and Marco Ferrario for their help
of dentistry. and collaboration in some of the dental technology sections.

Special thanks to my sister, Anna Massironi, for her participation in and support of
With the greatest pleasure, we devote a small space to recognize my didactic and scientific activities.
the names and contributions of all who have so generously Thanks are also due to my collaborators at the Gandini-Massironi dental offices: Sara
given their time and efort and let an indelible mark in our Scaiola, Mirella Ferri, Maria Rosa Farina, Cristina Colombi, Emanuela Badaracco, for their
memories. We ofer our most heartfelt thanks to you all. unstinting efforts and continuing support.
Romeo Pasceta
Thanks to Federico Di Primio, a dental technician par excellence and my collaborator for
many years. His consistent and conscientious work contributes to the success of my
Domenico Massironi professional activities.
My sincerest gratitude to Romeo Pascetta and Giuseppe Romeo, who are my friends, col· My sincere gratitude goes to Dr Domenico Massironi, who was kind enough to include
laborators, and co-authors. They are, above all, extraordinarily skilled dental technicians me in this project, providing new stimuli to my work and enriching my professional and
who create the prosthetic restorations for my clinical practice. Also to the dental techni· personal development.
cian Alberto Battistelli who has, for years, shared my passion and pursuit for precision Special thanks to my wife, Dr Stefania De Deo, for her consummate patience and
in prosthetic restoration. Without their expertise and technical skills, 1 would not be able invaluable assistance i n compiling the manuscript, and to my sons, Stefano and Giulio,
to present the restorations featured throughout this text. for their encouragement and support.
Thanks also to Dr Federico Ferraris for his dedication and organizational skills that
were so helpful in preparing this text. Giuseppe Romeo
To Professor Paola Gandini of Orthognathodontics at the University of Pisa, my heatfelt My professional esteem and thanks go to Dr Domenico Massironi, for his day-to-day
thanks for the presentation of the clinical cases we treated jointly in the offices we share. collaboration and for having involved me in the development of this manuscript.
"
T R 0 D u c T I 0
T
he authors are often asked by colleagues in the ing setting. Excessive thickness of bonding cement
scientific field why they are so ixated on pre also increases exposure at the margins, which i n turn
cision. Putting aside the philosophical merits of increases the risk of fracture and of dissolution of the
the question, it is important to deine the term. cement by saliva, all laying the groundwork for pros
Precisione, the Italian word for precision, can be used thetic ailure in the shot to medium term (Figs 1 to 3).
variously to mean (t) a quality of a person or object, In addition to reducing the chance of ailure, con·
(2) exactly within specific limits, or (3) execution of a trolling the marginal gap improves the patient's ability
task exactly as required, without error. These simple to achieve efective hygiene at home, thus minimizing
definitions clearly demonstrate that precision does plaque accumulation and preventing inflammation
not exist in an absolute sense because it refers to (Figs 4 to 9).
pre-established limits and conditions; therefore, the The principal causes of failure i n a prosthesis can
absolute level of precision can increase by degrees ad be described as either biologic or biomechanical in
ininitum. nature.
Besides allowing for the possibility of constant
improvement, the deinition also conveys subjectivity, Biologic causes include:
in the sense that each clinician forms a personal con • Secondary caries (Fig to)
cept of what constitutes precision in his or her own • Endodontic problems (Fig tt)
practice. As practitioners, we do this by setting limits • Periodontal problems {Fig 12)
of acceptability that are often based on an inflated
estimate of our personal skills.• It is thus futile to Biomechanical causes include:
attempt to standardize the concept of precision. With • Fracture of the bonding cement
regard to prosthetic restorations, the authors believe • Fracture of the root (Fig 13)
it is also a mistake to evaluate precision principally in • Fracture of the framework
terms of marginal it, as measured in microns. • Fracture of the ceramic
For the authors, it is not the elusive quality of pre· • Esthetic imperfections
cision that they seek so much as the least possible • Occlusion problems
imprecisio n - a standard that can be met in each case
and throughout everyday practice -while also being In the authors' clinical practice, the concept of pre
mindful of inherent statistical variability. Thus, for cision is closely aligned with accuracy, a concept that
example, the aim is to minimize the amount of bond is less reductive and thus more accommodating of
ing cement as well as its thickness, thereby minimiz the complexities involved in prosthetic treatment. We
ing the amount of contractile tension that occurs dur- believe it is more productive to evaluate, in terms of ,.
T R 0 D u c T I 0
T
he authors are often asked by colleagues in the ing setting. Excessive thickness of bonding cement
scientific field why they are so ixated on pre also increases exposure at the margins, which i n turn
cision. Putting aside the philosophical merits of increases the risk of fracture and of dissolution of the
the question, it is important to deine the term. cement by saliva, all laying the groundwork for pros
Precisione, the Italian word for precision, can be used thetic ailure in the shot to medium term (Figs 1 to 3).
variously to mean (t) a quality of a person or object, In addition to reducing the chance of ailure, con·
(2) exactly within specific limits, or (3) execution of a trolling the marginal gap improves the patient's ability
task exactly as required, without error. These simple to achieve efective hygiene at home, thus minimizing
definitions clearly demonstrate that precision does plaque accumulation and preventing inflammation
not exist in an absolute sense because it refers to (Figs 4 to 9).
pre-established limits and conditions; therefore, the The principal causes of failure i n a prosthesis can
absolute level of precision can increase by degrees ad be described as either biologic or biomechanical in
ininitum. nature.
Besides allowing for the possibility of constant
improvement, the deinition also conveys subjectivity, Biologic causes include:
in the sense that each clinician forms a personal con • Secondary caries (Fig to)
cept of what constitutes precision in his or her own • Endodontic problems (Fig tt)
practice. As practitioners, we do this by setting limits • Periodontal problems {Fig 12)
of acceptability that are often based on an inflated
estimate of our personal skills.• It is thus futile to Biomechanical causes include:
attempt to standardize the concept of precision. With • Fracture of the bonding cement
regard to prosthetic restorations, the authors believe • Fracture of the root (Fig 13)
it is also a mistake to evaluate precision principally in • Fracture of the framework
terms of marginal it, as measured in microns. • Fracture of the ceramic
For the authors, it is not the elusive quality of pre· • Esthetic imperfections
cision that they seek so much as the least possible • Occlusion problems
imprecisio n - a standard that can be met in each case
and throughout everyday practice -while also being In the authors' clinical practice, the concept of pre
mindful of inherent statistical variability. Thus, for cision is closely aligned with accuracy, a concept that
example, the aim is to minimize the amount of bond is less reductive and thus more accommodating of
ing cement as well as its thickness, thereby minimiz the complexities involved in prosthetic treatment. We
ing the amount of contractile tension that occurs dur- believe it is more productive to evaluate, in terms of ,.
Introduction
P R E C ISI O N?
WH AT IS T H E M E A N I N G OF A L L T H IS
Figs 4 and 5 Clinical case before and after rehabilitation. which involved the replacement of esthetically incongruent prosthetic restorations.
The shape was the primary problem. as seen in Fig 8. The central i ncisor prostheses have a width-length ratio of almost U. which gives
them a square appearance. rather than a ratio of 0.75,0.80. which generally corresponds to the most esthetically pleasing shape.1-4 The lack
�1g 1 A health ¥ tooth removed for periodontal � easons. The tooth was processed and sectioned after of marginal adaptation and the subsequent gi ngival recession. present at all of the maxillary i n cisors. is visible. The new rehabilitation fea
being embedded in methacrylate resin to exam
'"' the marg•nat adaptatiOn by means of a miCroscope.
tures the proper shape and length of the crowns. The natural appearance was also achieved by the shifting of the g i ngival zenith to a more
Fi� 2 An image of a collarless metal-cerami c restoration magnified 100 X under polarized light. distal position with respect to the central axis of the teeth.
after sectioning via abrasion. Note the large mar
ginal gap (about 100 pml between the ceramiC .
crown and the underlying tissue. Fig 6 Lateral image of Fig 8 through a Zeiss OPMI 1 operating microscope with integrated circular flash. I n this 25 X enlargement. note the
Fig 3 Another section of the same restoration from a different are shows an even larger degree of imperfection of the marginal adaptation and the extent of gingival recession.
� marginal gap. fracture zones in the bonding cement. and
a lack of cement •n the most external area. whiCh IS 1n contact w1th the salivary fluids. Fig 7 The same area in a photograph taken 6 months after cementation of the new feldspathic ceramic prosthesis.
Introduction
P R E C ISI O N?
WH AT IS T H E M E A N I N G OF A L L T H IS
Figs 4 and 5 Clinical case before and after rehabilitation. which involved the replacement of esthetically incongruent prosthetic restorations.
The shape was the primary problem. as seen in Fig 8. The central i ncisor prostheses have a width-length ratio of almost U. which gives
them a square appearance. rather than a ratio of 0.75,0.80. which generally corresponds to the most esthetically pleasing shape.1-4 The lack
�1g 1 A health ¥ tooth removed for periodontal � easons. The tooth was processed and sectioned after of marginal adaptation and the subsequent gi ngival recession. present at all of the maxillary i n cisors. is visible. The new rehabilitation fea
being embedded in methacrylate resin to exam
'"' the marg•nat adaptatiOn by means of a miCroscope.
tures the proper shape and length of the crowns. The natural appearance was also achieved by the shifting of the g i ngival zenith to a more
Fi� 2 An image of a collarless metal-cerami c restoration magnified 100 X under polarized light. distal position with respect to the central axis of the teeth.
after sectioning via abrasion. Note the large mar
ginal gap (about 100 pml between the ceramiC .
crown and the underlying tissue. Fig 6 Lateral image of Fig 8 through a Zeiss OPMI 1 operating microscope with integrated circular flash. I n this 25 X enlargement. note the
Fig 3 Another section of the same restoration from a different are shows an even larger degree of imperfection of the marginal adaptation and the extent of gingival recession.
� marginal gap. fracture zones in the bonding cement. and
a lack of cement •n the most external area. whiCh IS 1n contact w1th the salivary fluids. Fig 7 The same area in a photograph taken 6 months after cementation of the new feldspathic ceramic prosthesis.
Introduction
views of the same clinical casnhown in Figs 8 to l l through the operating microscope
��8dand�::::�lateral
:��ly� ::�:;
figs g fig 10 Secondary caries is the most common cause of prosthetic failure and the consequent loss of the seal around the prosthesis where it meets
t"[� tlng the chn _ "a l Sltu atiDn 6 months after cementation . Note the perfect esthetic
(at different magnificatio n, 20 x and the tooth surface. This tooth was removed for periodontal reasons. and secondary caries is evident on the border between the gold-resin crown
i ·
integration in relation to the and the tooth. fig 11 Endodontic (biologic( problems are often the cause of prosthetic failure. as seen in this radiograph showing a periapical lesion
b · e marg1ns ' 11us tra te th e correct emergence profile and an ncellent interface
with the soft tissues. of the root of a maxillary right first premolar that served as an abutment for a fixed partial denture. The patient was suffering from a n acute
abscess. The presence of apical radiolucency is a sure sign of infection. fig 1 2 This tooth was restored with a cast gold crown. then extracted
because of worsening periodontal disease and the complete loss of gingival support. It is the clinician's responsibility to evaluate periodontal
health throughout each stage of treatment, during the initial evaluation. before and during restoration. and. above all. during the periodic follow
up visits. fig 13 A nonvital tooth. reconstructed with a gold post and core and a metal-ceramic crown. fractured at the middle and coronal thirds of
the root. The tooth was removed consequent to an acute periodontal abscess. Even when there are no initial periodontal symptoms. a tooth root
with a fracture near the middle third has a very poor prognosis.
5
Introduction
views of the same clinical casnhown in Figs 8 to l l through the operating microscope
��8dand�::::�lateral
:��ly� ::�:;
figs g fig 10 Secondary caries is the most common cause of prosthetic failure and the consequent loss of the seal around the prosthesis where it meets
t"[� tlng the chn _ "a l Sltu atiDn 6 months after cementation . Note the perfect esthetic
(at different magnificatio n, 20 x and the tooth surface. This tooth was removed for periodontal reasons. and secondary caries is evident on the border between the gold-resin crown
i ·
integration in relation to the and the tooth. fig 11 Endodontic (biologic( problems are often the cause of prosthetic failure. as seen in this radiograph showing a periapical lesion
b · e marg1ns ' 11us tra te th e correct emergence profile and an ncellent interface
with the soft tissues. of the root of a maxillary right first premolar that served as an abutment for a fixed partial denture. The patient was suffering from a n acute
abscess. The presence of apical radiolucency is a sure sign of infection. fig 1 2 This tooth was restored with a cast gold crown. then extracted
because of worsening periodontal disease and the complete loss of gingival support. It is the clinician's responsibility to evaluate periodontal
health throughout each stage of treatment, during the initial evaluation. before and during restoration. and. above all. during the periodic follow
up visits. fig 13 A nonvital tooth. reconstructed with a gold post and core and a metal-ceramic crown. fractured at the middle and coronal thirds of
the root. The tooth was removed consequent to an acute periodontal abscess. Even when there are no initial periodontal symptoms. a tooth root
with a fracture near the middle third has a very poor prognosis.
5
Introduction I
. accuracy, not only the margins but also the complex REFERENCES
operative steps, all conceived, planned, and per·
formed at high magnification (Figs 14 to 17).
1. Mitchell A. Pintado MR. Douglas WH. Nondestructive,
Esthetics and precision often do not coexist com·
in vitro quantiication of crown margins. J Prosthet Dent
fotably; indeed, it is not unusual to find one empha·
>oo1:Bs:s7s-sB4.
sized more than the other in prosthetic procedures.
2. Rufenacht CR. Fundamentals of Esthetics. Berlin: Quin·
Proponents of the esthetic view sometimes assert
tessence, 1990.
that excessive precision is not necessary to the health
3- Rufenacht CR. Principles of Esthetic Integration. Berlin:
of periodontal tissues, while precision proponents
Quintessence, 2000.
extol the vitues of metal, the only material that can
4- Chiche G, Pinault A. Esthetics of Anterior Fixed Prosth
guarantee precise margins (Figs 18 and 19). odontics. Chicago: Quintessence, 1994.
The authors' working philosophy centers instead
on recovery of the patient's health-the overriding
goal of all medical treatment-while seeking to opti·
malty satisfy all functional and esthetic requirements
of the patient.
It is around this philosophy that the authors have
formed a clinical and laboratory prosthetic team capa·
ble of meeting the demands of all types of rehabili
tative therapy, both esthetic and functional, while
upholding the principles of precision and practicing
techniques that are compatible with the material
being used (Figs 20 to 25). •
F1g 14 Detail of the margin of a tooth prepared for complete coverage 125 X magnification). The retraction cord is placed before
the i m p res
sion is taken.
Fig 15 The same restoration at a subsequent clinical stage. after placement of the gold -palladium coping !title gold 500.1125X
magnification).
Introduction I
. accuracy, not only the margins but also the complex REFERENCES
operative steps, all conceived, planned, and per·
formed at high magnification (Figs 14 to 17).
1. Mitchell A. Pintado MR. Douglas WH. Nondestructive,
Esthetics and precision often do not coexist com·
in vitro quantiication of crown margins. J Prosthet Dent
fotably; indeed, it is not unusual to find one empha·
>oo1:Bs:s7s-sB4.
sized more than the other in prosthetic procedures.
2. Rufenacht CR. Fundamentals of Esthetics. Berlin: Quin·
Proponents of the esthetic view sometimes assert
tessence, 1990.
that excessive precision is not necessary to the health
3- Rufenacht CR. Principles of Esthetic Integration. Berlin:
of periodontal tissues, while precision proponents
Quintessence, 2000.
extol the vitues of metal, the only material that can
4- Chiche G, Pinault A. Esthetics of Anterior Fixed Prosth
guarantee precise margins (Figs 18 and 19). odontics. Chicago: Quintessence, 1994.
The authors' working philosophy centers instead
on recovery of the patient's health-the overriding
goal of all medical treatment-while seeking to opti·
malty satisfy all functional and esthetic requirements
of the patient.
It is around this philosophy that the authors have
formed a clinical and laboratory prosthetic team capa·
ble of meeting the demands of all types of rehabili
tative therapy, both esthetic and functional, while
upholding the principles of precision and practicing
techniques that are compatible with the material
being used (Figs 20 to 25). •
F1g 14 Detail of the margin of a tooth prepared for complete coverage 125 X magnification). The retraction cord is placed before
the i m p res
sion is taken.
Fig 15 The same restoration at a subsequent clinical stage. after placement of the gold -palladium coping !title gold 500.1125X
magnification).
Introduction
figs 16 and 17 Extreme precision and accuracy are the goats at every operative stage. both clinical · · ·
and technical. as exemplified by the mar fig 22 Stereom1croscop 1c mw o f a core 1 e ss fetdspathic ceramic crown on the model before it is embedded in methacrylate resin .
ginal closure in wax and in the polishing of the metallic margin after completion of the waxing. . .
before the restoration is sent to the clinician.
g
figs 18and 1 Open prosthetic margin. both in a metal prosthesis !Fig 18} and in an all-ceramic fig 23 The section allows comparison of the clinical and h1stotog1c analyses.
. . .
imperfection is slight enough to be corrected with bonding cement. but the cement
crown (Fig 1 9} without a reinforcing core. This
wilt remain exposed to salivary fluids. which may lead to �
fig 24 !he same crown ce me n.te d wl'th co ' 0 site and after sectioning.
. . .
photographed at 1 DO X magn1f1cal1on usmg a microsco pe With a polar-
failure in the short to medium term. depending on the techniques and types of material
used for cementation. 1zed light source. Note I h e h 1g h d egree p reci� ion in marginal adaptation that can be achieved with this fetdspathic ceram1c.
·
. .
fig 20 Stereomicro scopic image of a metal crown with a high percentage of gold Fig 25 Even 1 n the case of co 11ar 1 ess me t a 1 - ceramic crowns · a high degree of marginal precision is possible. with values welt w1th1n the range
ltaptek. leach & Oilton}. seen in profile on an epoxy resin
base. obtained with an elastomer impression. of clinical acceptab ility.
Fig 21 Section of the Captek metal-cera mic crown after cementing with glass-ionom
er. embedding in methacryla te resin. and grinding (polar
ized tight: 1 00X magnificati on}. The radicular cement is blue. the bonding
cement is gray. and the metal-cera mic is black and tight gray.
high magnificatio n also allows visibility of the dentinal tubules. The
Introduction
figs 16 and 17 Extreme precision and accuracy are the goats at every operative stage. both clinical · · ·
and technical. as exemplified by the mar fig 22 Stereom1croscop 1c mw o f a core 1 e ss fetdspathic ceramic crown on the model before it is embedded in methacrylate resin .
ginal closure in wax and in the polishing of the metallic margin after completion of the waxing. . .
before the restoration is sent to the clinician.
g
figs 18and 1 Open prosthetic margin. both in a metal prosthesis !Fig 18} and in an all-ceramic fig 23 The section allows comparison of the clinical and h1stotog1c analyses.
. . .
imperfection is slight enough to be corrected with bonding cement. but the cement
crown (Fig 1 9} without a reinforcing core. This
wilt remain exposed to salivary fluids. which may lead to �
fig 24 !he same crown ce me n.te d wl'th co ' 0 site and after sectioning.
. . .
photographed at 1 DO X magn1f1cal1on usmg a microsco pe With a polar-
failure in the short to medium term. depending on the techniques and types of material
used for cementation. 1zed light source. Note I h e h 1g h d egree p reci� ion in marginal adaptation that can be achieved with this fetdspathic ceram1c.
·
. .
fig 20 Stereomicro scopic image of a metal crown with a high percentage of gold Fig 25 Even 1 n the case of co 11ar 1 ess me t a 1 - ceramic crowns · a high degree of marginal precision is possible. with values welt w1th1n the range
ltaptek. leach & Oilton}. seen in profile on an epoxy resin
base. obtained with an elastomer impression. of clinical acceptab ility.
Fig 21 Section of the Captek metal-cera mic crown after cementing with glass-ionom
er. embedding in methacryla te resin. and grinding (polar
ized tight: 1 00X magnificati on}. The radicular cement is blue. the bonding
cement is gray. and the metal-cera mic is black and tight gray.
high magnificatio n also allows visibility of the dentinal tubules. The
C H A P T E R
MA NAGI N G T H E TREATM E N T
PLAN WITH THE PROSTHETIC
TEAM
D IAG N O S I S A N D COLLECTI O N O F Clin ical procedures for treatment

C L I N ICAL I N FO R M ATION p la n n i n g
In medical practice, o n e or t h e fundamental steps in A treatment plan can b e designed only after the
the development and implementation or a thera patient's initial visit has been properly conducted and
peutic plan is the clinical diagnosis. which is estab medical history data has been collected. After the
lished through patient examination and analysis or patient has been informed about the condition or the
clinical test results. The same is true in dentistry, dentition and soft tissues. it is desirable to encour
where the diagnosis is based on a clinical examina age a collaborative relationship6 with him or her. The
tion (Figs 1-1 to 1-3) that focuses on the area in patient must be motivated to control bacterial plaque
volved and on evaluation or diagnostic records, and, if necessary. to manage caries and periodontal
often including intraoral radiographs (eg, bitewing disease. the two most common pathologies or the
radiographs. single or multiple apical radiographs. oral cavity, and understand their etiologies.
panoramic radiographs'·') and. occasionally, com The radiographs taken after the clinical examina
puterized axial tomography (CAl) scans. The analy tion assist in formulation of the correct diagnosis
sis or diagnostic radiographs is supported by evalu and subsequent treatment plan. For patients with
ation or a diagnostic cast mounted in an articulator periodontal conditions. treatment planning must be
using an anatomic facebow (through a transfer sys deferred until after completion or the phase one ther
tem) or. in more complex clinical cases. a kinematic apy and Initial and final probings (Figs 1-5 to 1-9). Fig 1-1 C li n i ca l examination should identify existing pathologies. As much information as poss1ble should be gathered to make an accurate
diagnosis and a suitable treatment plan. It is important to perform a preliminary periodontal probing of the area to be treated before decid
racebowJ-s (Fig 1-4). Clinical examination and record Armed with the clinical data supplied by complete
ing on the treatment method. Figs 1-2 and 1-3 Clinical examination reveals any anomalies of previous restorations. in terms of shape a n d size.
analysis are not discussed in this text. Attention is mouth radiographs (at least 16) (Figs 1-10 to 1-14 By taking photographs with a graded millimeter scale leg. a periodontal probe) next to the tooth. It is possible to provide the laboratory tech
nician with Important visual points of reference. F1g 1-4 Axlographic record in a patient requiring a complete rehabilitation. which makes it
instead focused on diagnosis and the fabrication and 1-18). panoramic radiographs (Figs 1-15 to 1-17), necessary to Identify the individual hinge axis In order to record and set the values relating to the frontal eminence a n d the B e nnett a ngle.
or a diagnostic cast to determine the feasibility or the periodontal chart (see Fig 1-9), and, above all. Fig 1-5 Frontal view of dentition in maximum intercuspation in a young female patient. In good clinical hulth. who initially came to the
author's office for a general checkup. Fig 1-6 Periodontal probing yields pathologic values typ1cal of penodontal disuse. which 1s often silt
restorative treatment. Information about the patient's ability and willing- . specifiC and generally correlated with the patient's Inability to control bacterial plaque 1 n that aru.
10
11
C H A P T E R
MA NAGI N G T H E TREATM E N T
PLAN WITH THE PROSTHETIC
TEAM
D IAG N O S I S A N D COLLECTI O N O F Clin ical procedures for treatment

C L I N ICAL I N FO R M ATION p la n n i n g
In medical practice, o n e or t h e fundamental steps in A treatment plan can b e designed only after the
the development and implementation or a thera patient's initial visit has been properly conducted and
peutic plan is the clinical diagnosis. which is estab medical history data has been collected. After the
lished through patient examination and analysis or patient has been informed about the condition or the
clinical test results. The same is true in dentistry, dentition and soft tissues. it is desirable to encour
where the diagnosis is based on a clinical examina age a collaborative relationship6 with him or her. The
tion (Figs 1-1 to 1-3) that focuses on the area in patient must be motivated to control bacterial plaque
volved and on evaluation or diagnostic records, and, if necessary. to manage caries and periodontal
often including intraoral radiographs (eg, bitewing disease. the two most common pathologies or the
radiographs. single or multiple apical radiographs. oral cavity, and understand their etiologies.
panoramic radiographs'·') and. occasionally, com The radiographs taken after the clinical examina
puterized axial tomography (CAl) scans. The analy tion assist in formulation of the correct diagnosis
sis or diagnostic radiographs is supported by evalu and subsequent treatment plan. For patients with
ation or a diagnostic cast mounted in an articulator periodontal conditions. treatment planning must be
using an anatomic facebow (through a transfer sys deferred until after completion or the phase one ther
tem) or. in more complex clinical cases. a kinematic apy and Initial and final probings (Figs 1-5 to 1-9). Fig 1-1 C li n i ca l examination should identify existing pathologies. As much information as poss1ble should be gathered to make an accurate
diagnosis and a suitable treatment plan. It is important to perform a preliminary periodontal probing of the area to be treated before decid
racebowJ-s (Fig 1-4). Clinical examination and record Armed with the clinical data supplied by complete
ing on the treatment method. Figs 1-2 and 1-3 Clinical examination reveals any anomalies of previous restorations. in terms of shape a n d size.
analysis are not discussed in this text. Attention is mouth radiographs (at least 16) (Figs 1-10 to 1-14 By taking photographs with a graded millimeter scale leg. a periodontal probe) next to the tooth. It is possible to provide the laboratory tech
nician with Important visual points of reference. F1g 1-4 Axlographic record in a patient requiring a complete rehabilitation. which makes it
instead focused on diagnosis and the fabrication and 1-18). panoramic radiographs (Figs 1-15 to 1-17), necessary to Identify the individual hinge axis In order to record and set the values relating to the frontal eminence a n d the B e nnett a ngle.
or a diagnostic cast to determine the feasibility or the periodontal chart (see Fig 1-9), and, above all. Fig 1-5 Frontal view of dentition in maximum intercuspation in a young female patient. In good clinical hulth. who initially came to the
author's office for a general checkup. Fig 1-6 Periodontal probing yields pathologic values typ1cal of penodontal disuse. which 1s often silt
restorative treatment. Information about the patient's ability and willing- . specifiC and generally correlated with the patient's Inability to control bacterial plaque 1 n that aru.
10
11
CHAPTER 1
Managing the Treatment Plan with the Prosthetic Team
. ness to control bacterial plaque (Figs 1-19 to 1-24), An esthetic and functional outcome cannot be
the clinician can discuss the treatment plan during left to chance; it proceeds from a sequence of clini
the patient's next visit. cal steps that include phase one therapy, provision·
All stages of prosthetic restoration presuppose al prosthesis fabrication, tooth preparation, proper
the health of the patient. Rehabilitation begins only gingival retraction, i mpression taking, and, finally,
after any necessay phase one therapy has been cementation. These stages can be perceived as a
completed and the patient has agreed to follow "clinical puzzle," no piece of which may be over
hygiene guidelines. A special dental hygiene pro looked or ignored without jeopardizing the success MAXILLA
gram can be implemented for patients with immedi of the treatment. .
ate needs and/or a predisposition for disorders of

the oral cavity (Figs 1-25 to 1-29).
Occlusal
Palatal
1° 10/07198
2° 16/09/98
3° 23/12198
Buccal
Occlusal
lingual
Figs 1-7 and 1-8 Subsequent series of 16 complete-mouth radiographs highlights a serious and generalized periodontal pathol
ogy. with specific areas more compromised.
Fig 1-9 The periodontal probing yields high values and shows areas of bifurcation and trifurcation affected by active peri
odontal disease. Only pathologic values have been marked in the picture.
12
IS
CHAPTER 1
. ness to control bacterial plaque (Figs 1-19 to 1-24), An esthetic and functional outcome cannot be
the clinician can discuss the treatment plan during left to chance; it proceeds from a sequence of clini
the patient's next visit. cal steps that include phase one therapy, provision·
All stages of prosthetic restoration presuppose al prosthesis fabrication, tooth preparation, proper
the health of the patient. Rehabilitation begins only gingival retraction, i mpression taking, and, finally,
after any necessay phase one therapy has been cementation. These stages can be perceived as a
completed and the patient has agreed to follow "clinical puzzle," no piece of which may be over
hygiene guidelines. A special dental hygiene pro looked or ignored without jeopardizing the success MAXILLA
gram can be implemented for patients with immedi of the treatment. .
ate needs and/or a predisposition for disorders of

the oral cavity (Figs 1-25 to 1-29).
Occlusal
Palatal
1° 10/07198
2° 16/09/98
3° 23/12198
Buccal
Occlusal
lingual
Figs 1-7 and 1-8 Subsequent series of 16 complete-mouth radiographs highlights a serious and generalized periodontal pathol
ogy. with specific areas more compromised.
Fig 1-9 The periodontal probing yields high values and shows areas of bifurcation and trifurcation affected by active peri
odontal disease. Only pathologic values have been marked in the picture.
12
IS
CHAPTER 1
Figs 1-13 and 1-14 Anterior teeth before and after prosthetic treatment. The two sets of radiographs show the final orthodontic intrusion and
Figs 1-10 o 1-12 Complete-mouth radiographs can be used for diagnostic purposes before treatment and for verification after complex treat the vital pulp in the teeth prepared for prosthetics. The goal was to stabilize and splint the teeth and to prevent the recurrence of d e ntal pro
ment. These are radiographs of the situation at initial presentation. following dental hygiene procedures. and immediately after treatment. trusion.
respectively. in a 50-year-old female patient with serious periodontal disease. showing flaring of the anterior teeth and loss of some poste
rior teeth resulting from impairment of the furcation areas. The patient underwent resective periodontal treatment. followed by orthodontic Figs 1-15 and 1-16 Pre- and posttreatment panoramic radiographs of a 75-year-old patient with periodontal disease and loss of several pos
treatment. implant placement. and finally prosthetic treatment. During the orthodontic treatment. the maxillary anterior teeth were intruded. terior teeth. The patient underwent a sinus augmentation on the left side and implant treatment prior to prosthetic rehabilitation.
as shown in the final radiographs !Fig 1 -111. Fig 1-17 Clinical case of a 55-year-old man who required replacement of a removable partial denture with a fixed prosthesis. The patient
received four osseointegrated screw-type implants in the mandible. a sinus augmentation. and four cylindrical i m p lants in the maxilla.
Fig 1-18 Complete-mouth radiographs taken at the end of treatment show a satisfactory outcome.
14
15
CHAPTER 1
Figs 1-13 and 1-14 Anterior teeth before and after prosthetic treatment. The two sets of radiographs show the final orthodontic intrusion and
Figs 1-10 o 1-12 Complete-mouth radiographs can be used for diagnostic purposes before treatment and for verification after complex treat the vital pulp in the teeth prepared for prosthetics. The goal was to stabilize and splint the teeth and to prevent the recurrence of d e ntal pro
ment. These are radiographs of the situation at initial presentation. following dental hygiene procedures. and immediately after treatment. trusion.
respectively. in a 50-year-old female patient with serious periodontal disease. showing flaring of the anterior teeth and loss of some poste
rior teeth resulting from impairment of the furcation areas. The patient underwent resective periodontal treatment. followed by orthodontic Figs 1-15 and 1-16 Pre- and posttreatment panoramic radiographs of a 75-year-old patient with periodontal disease and loss of several pos
treatment. implant placement. and finally prosthetic treatment. During the orthodontic treatment. the maxillary anterior teeth were intruded. terior teeth. The patient underwent a sinus augmentation on the left side and implant treatment prior to prosthetic rehabilitation.
as shown in the final radiographs !Fig 1 -111. Fig 1-17 Clinical case of a 55-year-old man who required replacement of a removable partial denture with a fixed prosthesis. The patient
received four osseointegrated screw-type implants in the mandible. a sinus augmentation. and four cylindrical i m p lants in the maxilla.
Fig 1-18 Complete-mouth radiographs taken at the end of treatment show a satisfactory outcome.
14
15
CHAPTER 1
Figs 1 - 1g D 1-24 II is fundamental to correctly perform dental hygiene procedures and fully motivate the patient. This is the basis of every treatment.
whether simple o r complex. Periodic prophylaxis planned in accordance with the patient's needs and habits is a follow-up to every treatment and con
tinues for life. These figures illustrate the clinical case of a 30-year-old woman who underwent hygiene procedures followed by resective periodon
tal treatment. The images demonstrate the clinical situation before !Figs 1 - 1 9. 1 - 1 1 . and 1 -131 and 7 years after (Figs 1 - 10. 1 - 11. and 1 -14) treat
ment. Note the periodontal health after the completion of treatment. Seven-year photographs were taken during a maintenance cleaning visit. Figs 1 -15
and 1-16 Nonsurgical treatment of gingival recession in the mandibular anterior area. shown at initial presentation and after 1 year. respectively. The
creeping epithelial attachment was obtained during several office visits without surgery. Fig 1-27 Analogous initial clinical situation in another case.
resolved without surgery. Fig 1-18 Healing after 6 months. Fig 1-2g Excellent periodontal health after 8 years. stable and free of inflammation o r relapse.
16 ,,
CHAPTER 1
Figs 1 - 1g D 1-24 II is fundamental to correctly perform dental hygiene procedures and fully motivate the patient. This is the basis of every treatment.
whether simple o r complex. Periodic prophylaxis planned in accordance with the patient's needs and habits is a follow-up to every treatment and con
tinues for life. These figures illustrate the clinical case of a 30-year-old woman who underwent hygiene procedures followed by resective periodon
tal treatment. The images demonstrate the clinical situation before !Figs 1 - 1 9. 1 - 1 1 . and 1 -131 and 7 years after (Figs 1 - 10. 1 - 11. and 1 -14) treat
ment. Note the periodontal health after the completion of treatment. Seven-year photographs were taken during a maintenance cleaning visit. Figs 1 -15
and 1-16 Nonsurgical treatment of gingival recession in the mandibular anterior area. shown at initial presentation and after 1 year. respectively. The
creeping epithelial attachment was obtained during several office visits without surgery. Fig 1-27 Analogous initial clinical situation in another case.
resolved without surgery. Fig 1-18 Healing after 6 months. Fig 1-2g Excellent periodontal health after 8 years. stable and free of inflammation o r relapse.
16 ,,
CHAPTER 1
Managing the Treatment Plan with the Prosthetic Team CLINICAL SUCCESS IS ALWAYS THE RESULT
OF DETAILED AND CAREFUL PROCEDURES
. Solving the clinical puzzle (Fig 1-30) always begins The diagnoslic waxup is prepared in the laborato
with the study of plaster casts made from two irre ry by a dental technician based on precise instruc
versible hydrocolloidal impressions. For this purpose, tions provided by the clinician. The clinician also
the use of a semi-adjustable articulator, usually set at advises the technician about the initial treatment
average values via an anatomic facebow, allows the plan, the remaining dentition, and the periodontal
clinician to analyze the patient's jaw movements. the condition to facilitate an accurate and detailed analy
relationship between the dental arches. and the sis of the teeth to be restored. During this stage it is
occlusion. Information learned from the casts is com important for the clinician to take a series of photo
bined with the data collected from the clinical exami graphs to document the current state of the patient's
nation and the diagnostic records to assess the fea teeth, smile, and general facial characteristics. These
sibility of diferent treatment options. photos are passed on to the technician to use during
the design stage to harmonize the waxup with the
patient's facial characteristics (Fig 1-34).
Laboratory Proced u res a n d the
After making the plaster cast. the dental technician
Diagnostic Waxup
makes a duplicate to record the patient's initial situa
I n addition to clinical procedures, the creation of a tion. Then, guided by the clinical instructions speciy
successful prosthesis requires the collaboration of a ing the number of remaining teeth, the technician
professional lab technician. It is the responsibility of gives priority to functional considerations by analyz
the lab technician to solve the "laboratoy puzzle" ing the patient's occlusion and checking the curves of
(Fig 1-31) through casting; trimming; and adding wax, Spee and Wilson (ie, the anteroposterior and media
metal, acrylic resin, and ceramic material according to lateral aspects).
the treatment objectives. The esthetics are then considered. This encompass
In cases where treatment is aimed at restoring es the shape and size of the natural teeth and/or the
function and esthetics without making substantial prostheses to be replaced; the relationship of the
modifications, the technician's artistic skill seldom teeth to the soft tissue and the gingival margins; the
comes into play since a preprosthetic lab analysis presence of a deep bite or crossbite; diastemata be
may not be necessay (Figs 1-32 and 1-33). In more tween remaining teeth; and the dental-perioral tissues
complicated cases, however, the diagnostic waxup is relationship. This evaluation may indicate the need
essential to the diagnosis and the subsequent real for orthodontic or preprosthetic periodontal treat
ization of the treatment plan.7 Moreover, it facilitates ment, which should be discussed with the clinician
communication with the patient by illustrating a pos (Figs 1-35 to 1-42)."·" The esthetic evaluation may
sible restoration and the modifications to be made. indicate the ideal position of the teeth that might be
The diagnostic waxup is therefore useful in obtaining achievable through orthodontic treatment, or a need
informed consent and a pproval.s-00 to optimize the dental relationship with the soft tis
Fig 1-30 Clinical prosthetic puzzle. The satisfactory clinical outcome of prosthetic treatment requires the correct performance of all the clin
sues using mucogingival treatment to compensate for ical procedures involved. It is therefore necessary not to overlook any of the steps leading to the final resull.
any defects.•J-•4 . Fig 1-31 laboratory puzzle. The outcome of prosthetic treatment usually depends on the collaboration between the clinician and the dental
technician. Each must be familiar with and respect the others skills. The laboratory must strive for accuracy in all stages.
11
19
CHAPTER 1
Managing the Treatment Plan with the Prosthetic Team CLINICAL SUCCESS IS ALWAYS THE RESULT
OF DETAILED AND CAREFUL PROCEDURES
. Solving the clinical puzzle (Fig 1-30) always begins The diagnoslic waxup is prepared in the laborato
with the study of plaster casts made from two irre ry by a dental technician based on precise instruc
versible hydrocolloidal impressions. For this purpose, tions provided by the clinician. The clinician also
the use of a semi-adjustable articulator, usually set at advises the technician about the initial treatment
average values via an anatomic facebow, allows the plan, the remaining dentition, and the periodontal
clinician to analyze the patient's jaw movements. the condition to facilitate an accurate and detailed analy
relationship between the dental arches. and the sis of the teeth to be restored. During this stage it is
occlusion. Information learned from the casts is com important for the clinician to take a series of photo
bined with the data collected from the clinical exami graphs to document the current state of the patient's
nation and the diagnostic records to assess the fea teeth, smile, and general facial characteristics. These
sibility of diferent treatment options. photos are passed on to the technician to use during
the design stage to harmonize the waxup with the
patient's facial characteristics (Fig 1-34).
Laboratory Proced u res a n d the
After making the plaster cast. the dental technician
Diagnostic Waxup
makes a duplicate to record the patient's initial situa
I n addition to clinical procedures, the creation of a tion. Then, guided by the clinical instructions speciy
successful prosthesis requires the collaboration of a ing the number of remaining teeth, the technician
professional lab technician. It is the responsibility of gives priority to functional considerations by analyz
the lab technician to solve the "laboratoy puzzle" ing the patient's occlusion and checking the curves of
(Fig 1-31) through casting; trimming; and adding wax, Spee and Wilson (ie, the anteroposterior and media
metal, acrylic resin, and ceramic material according to lateral aspects).
the treatment objectives. The esthetics are then considered. This encompass
In cases where treatment is aimed at restoring es the shape and size of the natural teeth and/or the
function and esthetics without making substantial prostheses to be replaced; the relationship of the
modifications, the technician's artistic skill seldom teeth to the soft tissue and the gingival margins; the
comes into play since a preprosthetic lab analysis presence of a deep bite or crossbite; diastemata be
may not be necessay (Figs 1-32 and 1-33). In more tween remaining teeth; and the dental-perioral tissues
complicated cases, however, the diagnostic waxup is relationship. This evaluation may indicate the need
essential to the diagnosis and the subsequent real for orthodontic or preprosthetic periodontal treat
ization of the treatment plan.7 Moreover, it facilitates ment, which should be discussed with the clinician
communication with the patient by illustrating a pos (Figs 1-35 to 1-42)."·" The esthetic evaluation may
sible restoration and the modifications to be made. indicate the ideal position of the teeth that might be
The diagnostic waxup is therefore useful in obtaining achievable through orthodontic treatment, or a need
informed consent and a pproval.s-00 to optimize the dental relationship with the soft tis
Fig 1-30 Clinical prosthetic puzzle. The satisfactory clinical outcome of prosthetic treatment requires the correct performance of all the clin
sues using mucogingival treatment to compensate for ical procedures involved. It is therefore necessary not to overlook any of the steps leading to the final resull.
any defects.•J-•4 . Fig 1-31 laboratory puzzle. The outcome of prosthetic treatment usually depends on the collaboration between the clinician and the dental
technician. Each must be familiar with and respect the others skills. The laboratory must strive for accuracy in all stages.
11
19
CHAPTER 1
Figs 1-32 to 1-33 Case of a single tooth restored with a new feldspalhic ceramic crown. The morphologic and chromatic characteristics of the contra
lateral tooth were copied. without creative input. Figure 1 - 3 2 shows the clinical situation before removal of the metal-cera m i c crown. Fig 1 - 4
Photographs of t h e patient's smile often express aspects of t h e patient's personality and expectations. Figs 1 - 3 5 t o 1-42 Diagnostic w a x u p . w h i c h
serves as a -laboratory treatment plan. - It is o n l y through the information received f r o m the clinician regarding the n u m b e r of residual t e e t h a n d
from t h e plaster cast in t h e articulator that t h e technician c a n m a k e a waxup of t h e final prosthesis. The type of treatment planned a l s o influ
ences the design of the waxup. The provisional prosthesis is prepared prior to manufacture of the final prosthesis to modify erroneous preexist
ing parameters and tooth positions. thus reestablishing proper form and function. In this clinical case. dental movements are planned i n view of
orthodontic treatment. which sometimes includes the correction of the curve of Spee. The illustrations show the case as it was initially present
ed in comparison with the waxups of the various segments.
0 21
CHAPTER 1
Figs 1-32 to 1-33 Case of a single tooth restored with a new feldspalhic ceramic crown. The morphologic and chromatic characteristics of the contra
lateral tooth were copied. without creative input. Figure 1 - 3 2 shows the clinical situation before removal of the metal-cera m i c crown. Fig 1 - 4
Photographs of t h e patient's smile often express aspects of t h e patient's personality and expectations. Figs 1 - 3 5 t o 1-42 Diagnostic w a x u p . w h i c h
serves as a -laboratory treatment plan. - It is o n l y through the information received f r o m the clinician regarding the n u m b e r of residual t e e t h a n d
from t h e plaster cast in t h e articulator that t h e technician c a n m a k e a waxup of t h e final prosthesis. The type of treatment planned a l s o influ
ences the design of the waxup. The provisional prosthesis is prepared prior to manufacture of the final prosthesis to modify erroneous preexist
ing parameters and tooth positions. thus reestablishing proper form and function. In this clinical case. dental movements are planned i n view of
orthodontic treatment. which sometimes includes the correction of the curve of Spee. The illustrations show the case as it was initially present
ed in comparison with the waxups of the various segments.
0 21
CHAPTER 1
II Once the diagnostic waxup is completed, the clin- visional prosthesis, as well as the techniques of
ician uses it to review the treatment plan with the tooth preparation and the characteristics of the var
patient, comparing it to the initial casts. Figures 1-43 ious impression materials. While the clinician and
to 1-57 present a case in which a diagnostic waxup technician must be responsible for their own tasks,
(see Fig 1-48) was used to facilitate a successful treat· they must share reciprocal awareness of the clinical
ment result. Care should be taken to explain the basic and technical procedures to become an efficient
FIG 1 -43 FIG 1 -44
intent of the waxup and the principal stages of the team, aimed at the correct diagnosis and treatment
treatment plan (Figs 1-58 and 1-59). of the patient.
Once any necessary endodontic treatment is com
pleted and prosthetic teeth have been prepared,
Prosthetic p la n n i n g as a team
fabrication of the restoration can begin. At this stage
The "prosthetic puzzle" involves clinical and labora it is necessary to choose the materials for the final
tory procedures and requires the collaboration of prosthesis. The selection of restorative materials de
the clinician and the dental technician to plan the pends primarily on function. Although several mate·
definitive prosthesis. rials are strong enough to connect multiple teeth,
The clinician needs to know what happens ater their esthetic qualities are not always optimal. Other
the i mpression is made and how the stone cast is materials, such as translucent ceramics that are
trimmed in order to provide instructions regarding applied like adhesive cement, are esthetically pleas
the intact tooth structure beyond the finish line of a ing. The clinician must decide on the restorative
tooth preparation. The technician needs to under materials at the beginning of the reconstructive phase
stand how the soft tissues are adapted with the proof treatment to best suit the prosthetic preparation .
FIG 1-45 FIG 1-46
Fig 1-43 Thirty-one-year-old female patient with metal-ceramic restorations on the nonvital maxillary lateral incisors and a
noticeable reddish-brown pigmentation of the maxillary right central incisor. which was devitalized in congruously 10 years
previously. Note the gingival exposure when the patient smiles. as well as the short upper lip. which. in combination with the
varying pigmentation of the teeth. the restorations. and the gingival margins. makes her smile decidedly unesthetic.
Fig 1-4 Close-up of the smile. showing part of the dental arches in occlusion. following an intermediate stage with first- and
second-stage provisional prostheses. the treatment plan includes placement of all-ceramic crowns for the lateral incisors
and ceramic veneers for the central in cisors. The goal is to reduce the overbite by shortening the teeth and altering their
shape. as shown in the waxup (see fig 1-481. In addition. the treatment plan includes lengthening the clinical crown. posi
tioning the gingival zeniths at an ideal level. and aligning the gingival margins with the cementoenamel junction. thus expos
ing the entire crown of the tooth to reduce the gummy smile and the overbite white maintaining the occlusal guidance.
Fig 1-45 Gingival contours are marked on the model by the dental technician. highlighting the i n complete extrusion of the cen
tral incisors and the anomalous position of the lateral incisors with respect to the canines and the central incisors.
Fig 1 -45 Correction is made on the plaster cast.
Figs 1-47 and 1 -48 Ideal position of the gingival contours is created on the plaster cast after a hypothetical periodontal treat
ment. following the newly traced lines and the new cervical limits. the next step is to modify the gingival scallop on the plas
ter cast with a suitable bur and complete the diagnostic waxup. attempting to reproduce in wax the ideal esthetic outcome as
proposed to the patient. The shape and anatomy of the teeth are redesigned by the dental technician with the aim of restor
ing the dominance of the anterior teeth.
FIG 1-47 FIG 1 -48

2
CHAPTER 1
II Once the diagnostic waxup is completed, the clin- visional prosthesis, as well as the techniques of
ician uses it to review the treatment plan with the tooth preparation and the characteristics of the var
patient, comparing it to the initial casts. Figures 1-43 ious impression materials. While the clinician and
to 1-57 present a case in which a diagnostic waxup technician must be responsible for their own tasks,
(see Fig 1-48) was used to facilitate a successful treat· they must share reciprocal awareness of the clinical
ment result. Care should be taken to explain the basic and technical procedures to become an efficient
FIG 1 -43 FIG 1 -44
intent of the waxup and the principal stages of the team, aimed at the correct diagnosis and treatment
treatment plan (Figs 1-58 and 1-59). of the patient.
Once any necessary endodontic treatment is com
pleted and prosthetic teeth have been prepared,
Prosthetic p la n n i n g as a team
fabrication of the restoration can begin. At this stage
The "prosthetic puzzle" involves clinical and labora it is necessary to choose the materials for the final
tory procedures and requires the collaboration of prosthesis. The selection of restorative materials de
the clinician and the dental technician to plan the pends primarily on function. Although several mate·
definitive prosthesis. rials are strong enough to connect multiple teeth,
The clinician needs to know what happens ater their esthetic qualities are not always optimal. Other
the i mpression is made and how the stone cast is materials, such as translucent ceramics that are
trimmed in order to provide instructions regarding applied like adhesive cement, are esthetically pleas
the intact tooth structure beyond the finish line of a ing. The clinician must decide on the restorative
tooth preparation. The technician needs to under materials at the beginning of the reconstructive phase
stand how the soft tissues are adapted with the proof treatment to best suit the prosthetic preparation .
FIG 1-45 FIG 1-46
Fig 1-43 Thirty-one-year-old female patient with metal-ceramic restorations on the nonvital maxillary lateral incisors and a
noticeable reddish-brown pigmentation of the maxillary right central incisor. which was devitalized in congruously 10 years
previously. Note the gingival exposure when the patient smiles. as well as the short upper lip. which. in combination with the
varying pigmentation of the teeth. the restorations. and the gingival margins. makes her smile decidedly unesthetic.
Fig 1-4 Close-up of the smile. showing part of the dental arches in occlusion. following an intermediate stage with first- and
second-stage provisional prostheses. the treatment plan includes placement of all-ceramic crowns for the lateral incisors
and ceramic veneers for the central in cisors. The goal is to reduce the overbite by shortening the teeth and altering their
shape. as shown in the waxup (see fig 1-481. In addition. the treatment plan includes lengthening the clinical crown. posi
tioning the gingival zeniths at an ideal level. and aligning the gingival margins with the cementoenamel junction. thus expos
ing the entire crown of the tooth to reduce the gummy smile and the overbite white maintaining the occlusal guidance.
Fig 1-45 Gingival contours are marked on the model by the dental technician. highlighting the i n complete extrusion of the cen
tral incisors and the anomalous position of the lateral incisors with respect to the canines and the central incisors.
Fig 1 -45 Correction is made on the plaster cast.
Figs 1-47 and 1 -48 Ideal position of the gingival contours is created on the plaster cast after a hypothetical periodontal treat
ment. following the newly traced lines and the new cervical limits. the next step is to modify the gingival scallop on the plas
ter cast with a suitable bur and complete the diagnostic waxup. attempting to reproduce in wax the ideal esthetic outcome as
proposed to the patient. The shape and anatomy of the teeth are redesigned by the dental technician with the aim of restor
ing the dominance of the anterior teeth.
FIG 1-47 FIG 1 -48

2
CHAPTER 1
Fig 1-4g Surgical crown lengthening of the six anterior teeth. Fig 1-54 Clinical situation after completion of the whitening. treatment and immediately prior to the preparati � n of the two veneers for the cen
tral incisors and the all-ceramic crowns for the lateral 1nc1sors. The second-stage prom10nal prostheSis. made from a duplicate of the
Fig 1-50 New position of the gingival tissue and the bone crest immediately following resective surgery.
waxup. is in place.
Fig 1-51 Clinical situation after removal of the old restorations.
Fig 1-55 Clinical photograph showing the superficial characteristics of the natural teeth. For the dental technician. use of a black background
Fig 1-52 Provisional prostheses in situ (see chapters 7 and 8). The nonvital teeth (the two lateral incisors and the right central incisor) can is helpful during layering of the ceramiC matenal.
now be whitened.
Figs 1-56a and 1-56b Lateral incisors after whitening and reconstruction with fiberglass posts and cores. The gingival tissues continue to
Fig 1-53 Only when the optimum level of whitening has been achieved can the two lateral incisors be restored with fiberglass posts and cores. regrow after the resective treatment.
4 25
CHAPTER 1
Fig 1-4g Surgical crown lengthening of the six anterior teeth. Fig 1-54 Clinical situation after completion of the whitening. treatment and immediately prior to the preparati � n of the two veneers for the cen
tral incisors and the all-ceramic crowns for the lateral 1nc1sors. The second-stage prom10nal prostheSis. made from a duplicate of the
Fig 1-50 New position of the gingival tissue and the bone crest immediately following resective surgery.
waxup. is in place.
Fig 1-51 Clinical situation after removal of the old restorations.
Fig 1-55 Clinical photograph showing the superficial characteristics of the natural teeth. For the dental technician. use of a black background
Fig 1-52 Provisional prostheses in situ (see chapters 7 and 8). The nonvital teeth (the two lateral incisors and the right central incisor) can is helpful during layering of the ceramiC matenal.
now be whitened.
Figs 1-56a and 1-56b Lateral incisors after whitening and reconstruction with fiberglass posts and cores. The gingival tissues continue to
Fig 1-53 Only when the optimum level of whitening has been achieved can the two lateral incisors be restored with fiberglass posts and cores. regrow after the resective treatment.
4 25
fig I '"' tllnlctl rou rutur1d wllh ��tnrtnl 111 ttrfnlr m11111al Cumparlun wllh 111 mandibular lulh In ptolrualon 1how1 uullonl ftg 1 �7o Clou up of tho rutorod centrallncllofl
ftgtl ��and 1 17g Ooneral appurance of the palltnl before and after trutmtnl
uthalll lniiQtlllol
l1g I �lb Clua up vttw of tha rntoralt�nl 10 d1y1 afttt tdhnlva ttm�tlallon
l1g f olr nd I ./d fJ•I.,f•d v11w1 allht amlla bllure 11d 11111 rutorallva trutmenl
l7
fig I '"' tllnlctl rou rutur1d wllh ��tnrtnl 111 ttrfnlr m11111al Cumparlun wllh 111 mandibular lulh In ptolrualon 1how1 uullonl ftg 1 �7o Clou up of tho rutorod centrallncllofl
ftgtl ��and 1 17g Ooneral appurance of the palltnl before and after trutmtnl
uthalll lniiQtlllol
l1g I �lb Clua up vttw of tha rntoralt�nl 10 d1y1 afttt tdhnlva ttm�tlallon
l1g f olr nd I ./d fJ•I.,f•d v11w1 allht amlla bllure 11d 11111 rutorallva trutmenl
l7
CHAPTER 1
Managing the Treatment Plan with the Prosthetic Team I
• and reconstruction to be implemented. Not only lranslucent feldspathic ceramic crowns without a core
would a translucent restoration be unattractive over and the latest generation of pressed ceramics.
a tooth preparation in gold or a similar material, but All-ceramic crowns with a core of either aluminum
the two materials would be dificult to bond effec or zirconium provide greater resistance to stress
tively, resulting in significant short-term problems. In than other materials, but the opaque core reduces
the same way, a so-degree shoulder preparation the difusion of light, giving the restoration a less
does not provide the proper support for a felds natural efect. >7
pathic ceramic crown because the porcelain materi The latest melal reinforcements, such as Captek
al would be subjected to excessive tensile stress (Leach & Dillon) and those obtained by electroplating
FIG 1-58 FIG 1-59
that could result in marginal fractures during chew (AGC, Wealand), are slightly less attractive than
ing or even during cementation. porcelain with alumina or zirconia core, but the yellow
The pivotal actor between the various restorative hue allows for a more natural coloration of the ceram Rgs 1-58 and 1-S g With the diagnostic wax up completed and all of the clinical and operative information gathered. the clinician may now dis
cuss the situation with the patient. showing the initial photographs. the radiographs. and the result of dental hygiene procedures. Models of
materials is usually a matter of esthetics, both sub ic coating than that of traditional metal-ceramic com healthy teeth can be useful as examples to compare with the diagnostic waxup .
jective and objective. In the authors' opinion, sub binations. Metal-ceramic crowns, although subjec
jecrive esthetics should not be of great concern to tively considered the least attractive, are usually the
clinicians because personal taste depends on anato solution of choice for functional treatments involv
my and the harmony of the whole, which are specific ing several connected elements. Dental technicians
to each patient. Objective esthetics refers to factors are most accustomed to working with this type of
such as the type of core used for the prosthetic restorative material.
restoration and the inish line chosen by the clini In terms of objective esthetics, the margin is
cian. However, even objective factors possess greater most attractive if it is made entirely of ceramic mate
and lesser degrees of esthetic properties. rial (collarless) rather than with a metallic margin,
Objective esthetics can be optimized by combin whether covered in ceramic (micromargin) or not.
ing restorative materials and margin types. Follow The interdependence of the stages involved in
ing are some treatment options: preparing the provisional prosthesis- retracting the
soft tissues, making the impression, tying the
t. Feldspathic porcelain laminate veneer ramework in the patient's mouth, and, finally, test
2. Feldspathic porcelain crown ing the ceramic material and cementation- oblige
3- Pressed ceramic crown'S the clinician to follow a strict clinical procedure and
4- All-ceramic crown with alumina or zirconia core to cooperate with the dental technician.
5 - Collarless metal-ceramic restoration Each practitioner should follow strict guidelines • PROSTHTIC PREPARATIONS I m p ression materials a n d worki n g
6. Metal-ceramic crown with margins covered in to reduce the number of procedures required and casts
ceramic (micromargin) hence the opportunities for error, and facilitate the This text examines many of the procedures i nvolved
7. Metal-ceramic crown with evident metal margin realization of each treatment plan. The success of the in treatment using a prosthetic restoration, focusing It is the authors' conviction that distortion of mate
prosthetic restoration depends on the correct assem principally on the critical stages that determine a rials (especially impression materials) is the leading
Laminate veneers usually yield the best esthetic re bly of each piece in the prosthetic puzzle. Excellence successful treatment outcome to help eliminate error cause of unexpected error and the primary short
sult because of both their translucency and their in treatment can be achieved only by continual im and avoid insurmountable obstacles for the labora coming of prosthetic products. Only through careful
marginal positioning, which is normally supragingi provement of each procedure. .. tory technician . control to avoid subjecting materials to excessive .
val or juxtagingival.16 They are followed closely by
1
CHAPTER 1
Managing the Treatment Plan with the Prosthetic Team I
• and reconstruction to be implemented. Not only lranslucent feldspathic ceramic crowns without a core
would a translucent restoration be unattractive over and the latest generation of pressed ceramics.
a tooth preparation in gold or a similar material, but All-ceramic crowns with a core of either aluminum
the two materials would be dificult to bond effec or zirconium provide greater resistance to stress
tively, resulting in significant short-term problems. In than other materials, but the opaque core reduces
the same way, a so-degree shoulder preparation the difusion of light, giving the restoration a less
does not provide the proper support for a felds natural efect. >7
pathic ceramic crown because the porcelain materi The latest melal reinforcements, such as Captek
al would be subjected to excessive tensile stress (Leach & Dillon) and those obtained by electroplating
FIG 1-58 FIG 1-59
that could result in marginal fractures during chew (AGC, Wealand), are slightly less attractive than
ing or even during cementation. porcelain with alumina or zirconia core, but the yellow
The pivotal actor between the various restorative hue allows for a more natural coloration of the ceram Rgs 1-58 and 1-S g With the diagnostic wax up completed and all of the clinical and operative information gathered. the clinician may now dis
cuss the situation with the patient. showing the initial photographs. the radiographs. and the result of dental hygiene procedures. Models of
materials is usually a matter of esthetics, both sub ic coating than that of traditional metal-ceramic com healthy teeth can be useful as examples to compare with the diagnostic waxup .
jective and objective. In the authors' opinion, sub binations. Metal-ceramic crowns, although subjec
jecrive esthetics should not be of great concern to tively considered the least attractive, are usually the
clinicians because personal taste depends on anato solution of choice for functional treatments involv
my and the harmony of the whole, which are specific ing several connected elements. Dental technicians
to each patient. Objective esthetics refers to factors are most accustomed to working with this type of
such as the type of core used for the prosthetic restorative material.
restoration and the inish line chosen by the clini In terms of objective esthetics, the margin is
cian. However, even objective factors possess greater most attractive if it is made entirely of ceramic mate
and lesser degrees of esthetic properties. rial (collarless) rather than with a metallic margin,
Objective esthetics can be optimized by combin whether covered in ceramic (micromargin) or not.
ing restorative materials and margin types. Follow The interdependence of the stages involved in
ing are some treatment options: preparing the provisional prosthesis- retracting the
soft tissues, making the impression, tying the
t. Feldspathic porcelain laminate veneer ramework in the patient's mouth, and, finally, test
2. Feldspathic porcelain crown ing the ceramic material and cementation- oblige
3- Pressed ceramic crown'S the clinician to follow a strict clinical procedure and
4- All-ceramic crown with alumina or zirconia core to cooperate with the dental technician.
5 - Collarless metal-ceramic restoration Each practitioner should follow strict guidelines • PROSTHTIC PREPARATIONS I m p ression materials a n d worki n g
6. Metal-ceramic crown with margins covered in to reduce the number of procedures required and casts
ceramic (micromargin) hence the opportunities for error, and facilitate the This text examines many of the procedures i nvolved
7. Metal-ceramic crown with evident metal margin realization of each treatment plan. The success of the in treatment using a prosthetic restoration, focusing It is the authors' conviction that distortion of mate
prosthetic restoration depends on the correct assem principally on the critical stages that determine a rials (especially impression materials) is the leading
Laminate veneers usually yield the best esthetic re bly of each piece in the prosthetic puzzle. Excellence successful treatment outcome to help eliminate error cause of unexpected error and the primary short
sult because of both their translucency and their in treatment can be achieved only by continual im and avoid insurmountable obstacles for the labora coming of prosthetic products. Only through careful
marginal positioning, which is normally supragingi provement of each procedure. .. tory technician . control to avoid subjecting materials to excessive .
val or juxtagingival.16 They are followed closely by
1
CHAPTER 1
. tension during clinical operations can clinicians hope the casting in the patient's mouth. the clinician
to consistently achieve maximum precision. lmpres· should evaluate it on the master cast with a stereo
sion materials are not infinitely elastic. If subjected microscope. If the setting is good on the master
to excessive stress. impression materials can become cast. magnification will reveal any discrepancy or
functionally compromised in ways that are not visi· distortion of the impression as compared to the
ble to the eye, thus altering the working cast and tooth from which it was prepared.
the definitive prosthesis. In cases of excessive discrepancy, the clinician
Accuracy tests for impression materials are per· should repeat the impression phase, but only after
formed in vitro. on areas free from the irregularities carefully checking and correcting all possible causes
FIG 1-60 FIG 1-61
and variations (such as undercuts) that are often of tension in the oral cavity, whether created by the
found during clinical examination or created by clin· clinician's intervention or a pre-existing condition. In
ical error during tooth preparation. The results of this case, every procedure involved in the making of ig 1-60 Following try-in of the framework in the patienl"s mouth. shiny spots inside the metallic cap reveal the tensions present i n the
the prosthesis will also need to be repeated. impression. which are reproduced in the laboratory on the cast.
these tests show vey high precision for polyvinyl
Fig 1 -61 Areas of friction are visible after the application of a highlighting enamel with a chloroform base.
siloxanes and polyethers.'8 However. expecting im When clinicians take impressions that respect the
pression materials to guarantee absolute precision elasticity limits of the impression materials. dental
i n all operating conditions is unrealistic. technicians make casts and prostheses that, once
Excessive tension on the surfaces of the prepared checked against the master cast according to preci
teeth can affect subsequent operative stages and sion standards, will adapt optimally in the patient's
even the fit of the definitive prosthesis. With this mouth. When imperfections in the impression are
understanding, clinicians must create preparations limited or absent, adaptation tests using materials
that do not exceed the limit of elasticity for impres such as friction-disclosing pastes. which are difficult
sion materials. to use and may cause excess thickness or bumps.
Once the impression has been taken. the next become unnecessary.'-" Slight frictions are thus a . cian, analyzing the result of their work and evaluat plex cases. A clinician can transfer the knowledge
stage involves the fabrication of the cast in the lab measure of how well the impression matches the ing the feasibility of using ceramic material to meet acquired in making single crowns to cases requiring
·
oratory and the patient try-in performed by the clin actual situation. the demands of the treatment plan. the rehabilitation of multiple teeth, though not, per
ician. If the impression has been fabricated with The authors believe it is important to use the Another possible source of error lies in the thick haps, without some d ificulty. Clinicians must under
compromised materials, the clinician will need to stereomicroscope (see chapter 2) to identify even ness of the prosthesis. both cervically and with stand the importance of a good preparation phase
use disclosing pastes (Fit Checker, GQ in combina the smallest friction. which appears as a glossy mark respect to the palate and occlusion. which is influ for making a successful impression and respect the
tion with difficult structural analyses to adapt a cor inside the metal (Figs 1-6o and 1-61) and can be enced by the preparation for the planned restora limitations of impression materials.
rect prosthesis from the faulty impression. A casting removed using a small tungsten-carbide bur. taking tion. Insufficient space in the preparation results in As complex treatments become predictable. the
made from an improper impression will not fit care not to touch the margin. excessive reduction of the thickness of the materials clinician may work on aspects that are usually con·
securely, creating excessive friction clutch or swing The inexperienced clinician can learn a great deal used to make the prosthesis. Overcontouring in pro sidered secondary to the prosthetic treatment plan.
ing when tried in the patient's mouth. Faulty impres from the analysis of a master cast developed from a files and margins can likewise result from an attempt Factors that are largely cosmetic, such as tooth
sions are very difficult or even impossible to adapt. precise impression; such a cast clearly shows all to maintain the proper thickness of the prosthetic bleaching, significantly contribute to optimal esthet·
Moreover. adaptation leads clinicians to use more aspects of the preparation as well as any errors. The restoration. ic results (Figs 1-62 to 1-102). ..
cement than would be acceptable in good clinical authors recommend that the inexperienced clinician If these procedures are carefully followed, clini·
practice. If there is a minor issue with adaptation of spend time in the laboratory with the dental techni- .. cians can confidently begin to undertake more com·
0
31
CHAPTER 1
. tension during clinical operations can clinicians hope the casting in the patient's mouth. the clinician
to consistently achieve maximum precision. lmpres· should evaluate it on the master cast with a stereo
sion materials are not infinitely elastic. If subjected microscope. If the setting is good on the master
to excessive stress. impression materials can become cast. magnification will reveal any discrepancy or
functionally compromised in ways that are not visi· distortion of the impression as compared to the
ble to the eye, thus altering the working cast and tooth from which it was prepared.
the definitive prosthesis. In cases of excessive discrepancy, the clinician
Accuracy tests for impression materials are per· should repeat the impression phase, but only after
formed in vitro. on areas free from the irregularities carefully checking and correcting all possible causes
FIG 1-60 FIG 1-61
and variations (such as undercuts) that are often of tension in the oral cavity, whether created by the
found during clinical examination or created by clin· clinician's intervention or a pre-existing condition. In
ical error during tooth preparation. The results of this case, every procedure involved in the making of ig 1-60 Following try-in of the framework in the patienl"s mouth. shiny spots inside the metallic cap reveal the tensions present i n the
the prosthesis will also need to be repeated. impression. which are reproduced in the laboratory on the cast.
these tests show vey high precision for polyvinyl
Fig 1 -61 Areas of friction are visible after the application of a highlighting enamel with a chloroform base.
siloxanes and polyethers.'8 However. expecting im When clinicians take impressions that respect the
pression materials to guarantee absolute precision elasticity limits of the impression materials. dental
i n all operating conditions is unrealistic. technicians make casts and prostheses that, once
Excessive tension on the surfaces of the prepared checked against the master cast according to preci
teeth can affect subsequent operative stages and sion standards, will adapt optimally in the patient's
even the fit of the definitive prosthesis. With this mouth. When imperfections in the impression are
understanding, clinicians must create preparations limited or absent, adaptation tests using materials
that do not exceed the limit of elasticity for impres such as friction-disclosing pastes. which are difficult
sion materials. to use and may cause excess thickness or bumps.
Once the impression has been taken. the next become unnecessary.'-" Slight frictions are thus a . cian, analyzing the result of their work and evaluat plex cases. A clinician can transfer the knowledge
stage involves the fabrication of the cast in the lab measure of how well the impression matches the ing the feasibility of using ceramic material to meet acquired in making single crowns to cases requiring
·
oratory and the patient try-in performed by the clin actual situation. the demands of the treatment plan. the rehabilitation of multiple teeth, though not, per
ician. If the impression has been fabricated with The authors believe it is important to use the Another possible source of error lies in the thick haps, without some d ificulty. Clinicians must under
compromised materials, the clinician will need to stereomicroscope (see chapter 2) to identify even ness of the prosthesis. both cervically and with stand the importance of a good preparation phase
use disclosing pastes (Fit Checker, GQ in combina the smallest friction. which appears as a glossy mark respect to the palate and occlusion. which is influ for making a successful impression and respect the
tion with difficult structural analyses to adapt a cor inside the metal (Figs 1-6o and 1-61) and can be enced by the preparation for the planned restora limitations of impression materials.
rect prosthesis from the faulty impression. A casting removed using a small tungsten-carbide bur. taking tion. Insufficient space in the preparation results in As complex treatments become predictable. the
made from an improper impression will not fit care not to touch the margin. excessive reduction of the thickness of the materials clinician may work on aspects that are usually con·
securely, creating excessive friction clutch or swing The inexperienced clinician can learn a great deal used to make the prosthesis. Overcontouring in pro sidered secondary to the prosthetic treatment plan.
ing when tried in the patient's mouth. Faulty impres from the analysis of a master cast developed from a files and margins can likewise result from an attempt Factors that are largely cosmetic, such as tooth
sions are very difficult or even impossible to adapt. precise impression; such a cast clearly shows all to maintain the proper thickness of the prosthetic bleaching, significantly contribute to optimal esthet·
Moreover. adaptation leads clinicians to use more aspects of the preparation as well as any errors. The restoration. ic results (Figs 1-62 to 1-102). ..
cement than would be acceptable in good clinical authors recommend that the inexperienced clinician If these procedures are carefully followed, clini·
practice. If there is a minor issue with adaptation of spend time in the laboratory with the dental techni- .. cians can confidently begin to undertake more com·
0
31
CHAPTER 1
Figs 1-62and 1-63 Before and after bleaching of heavily discolored nonvital leeth after the removal of the old metal-ceramic crowns. Bleaching Fig 1-66 Central incisor after bleaching and reconstruction with a fiberglass dowel. A provisional prosthesis with less-than-perfect shape a n d
was done in the clinician's office using a creamy mixture of hydrogen peroxide and sodium perborate applied to the inside of the devitalized color w a s cemented in place. but t h e patient found it acceptable. no d o u b t because it w a s a distinct im provement o v e r the previous ceramic
tooth. A layer of temporary cement (Cavil. 3M ESPEI was used to seal in the bleaching substance and was applied inside the provisional crown restoration. Fig 1-67 After rubber dam is removed. the effect of the bleaching treatment on the lateral incisor is obvious, the tooth is much
before sealing. The procedure was repeated four times at 1 -week intervals. Fig 1-64 A 24-year-old female patient presented with an acute lighter than the other teeth. Figs 1-6B and 1-6g After cementation of the feldspathic ceramic crown on the central incisor. the color of the right
abscess near the root apices of the maxillary right lateral and central incisors. The lateral incisor was moderately discolored. and the shape lateral incisor is much lighter than that of the heatlhy contralateral tooth. in anticipation of a possible relapse. Fig 1-70 Radiograph showing
and color of the metal-ceramic crown on the central incisor were problematic. Fig 1-65 Because of the obliteration of the canal. it was decid the healing of the endodontic lesion and the good outcome of the retrograde treatment. Figs 1-71 After cementation. 1-72 After 4 months.
ed to carry out an apicectomy and retrograde obturation IProroot. Oentsply) under microscopic magnification. greater uniformity of color between the two lateral incisors and the perfect esthetic integration of the right central i n cisor are evident. Fig
1-73 Esthetic integration of color and shape is visible from the occlusal view. where the correct morphology a n d spacing prepared by the
dental technician can be seen.
2
33
CHAPTER 1
Figs 1-62and 1-63 Before and after bleaching of heavily discolored nonvital leeth after the removal of the old metal-ceramic crowns. Bleaching Fig 1-66 Central incisor after bleaching and reconstruction with a fiberglass dowel. A provisional prosthesis with less-than-perfect shape a n d
was done in the clinician's office using a creamy mixture of hydrogen peroxide and sodium perborate applied to the inside of the devitalized color w a s cemented in place. but t h e patient found it acceptable. no d o u b t because it w a s a distinct im provement o v e r the previous ceramic
tooth. A layer of temporary cement (Cavil. 3M ESPEI was used to seal in the bleaching substance and was applied inside the provisional crown restoration. Fig 1-67 After rubber dam is removed. the effect of the bleaching treatment on the lateral incisor is obvious, the tooth is much
before sealing. The procedure was repeated four times at 1 -week intervals. Fig 1-64 A 24-year-old female patient presented with an acute lighter than the other teeth. Figs 1-6B and 1-6g After cementation of the feldspathic ceramic crown on the central incisor. the color of the right
abscess near the root apices of the maxillary right lateral and central incisors. The lateral incisor was moderately discolored. and the shape lateral incisor is much lighter than that of the heatlhy contralateral tooth. in anticipation of a possible relapse. Fig 1-70 Radiograph showing
and color of the metal-ceramic crown on the central incisor were problematic. Fig 1-65 Because of the obliteration of the canal. it was decid the healing of the endodontic lesion and the good outcome of the retrograde treatment. Figs 1-71 After cementation. 1-72 After 4 months.
ed to carry out an apicectomy and retrograde obturation IProroot. Oentsply) under microscopic magnification. greater uniformity of color between the two lateral incisors and the perfect esthetic integration of the right central i n cisor are evident. Fig
1-73 Esthetic integration of color and shape is visible from the occlusal view. where the correct morphology a n d spacing prepared by the
dental technician can be seen.
2
33
CHAPTER 1
1 -7 6
Fig 1-74 Clinical case o f a 38 - year-old male patient with significant periodontal disease. Metal-ceramic rehabilitation i s uneslhelic i n shape sion of the prepared anterior Ieeth. The right canine has been prepared for a laminate veneer. This was done after the tissues healed. about
and color. and secondary caries is present al l he cervical margins. Figs 1-75 and 1-76 Radiographic evaluation and a diagnostic wax up assist 10 months after periodontal surgery. The proper preparation of the Ieeth and the alignment of their surfaces. in frontal and especially
ed in the formulation of the treatment plan. which included the restoration of the anterior Ieeth after the dental hygiene procedures and occlusal views. are prerequisites for the success of all subsequent stages. both clinical and technical. Fig 1-82 Ceramic rehabilitation o n the
reseclive periodontal treatment. relrealmenl of the root canals. home bleaching treatment for the healthy Ieeth (those stained by tetracycline master stone cast. Fig 1 - 83 Master cast of the preparation for the right canine veneer. with incisal reduction and bull margin. Fig 1-4 Close
treatments. not those involved in the prosthetic rehabilitation) for at least 6 months. and whitening of the nonvital loolh preparations before up of the maxillary left tooth preparations. showing considerable whitening in the most apical areas. which is the most difficult and impor
the preproslhelic reconstruction. Fig 1-77 Marked difference in the color of the tooth preparations after removal of the metal-ceramic tant part of the tooth to conceal with a restoration if there is discoloration. In this phase. the tissues still show slight inflammation. mostly
restorations. This will be resolved by bleaching with hydrogen peroxide 130 vol) lvol 7.6%1 mixed wilh sodium perborale. Fig 1-78 Dentin because of lhe patient's poor oral hygiene regimen. II can be very imporlan l l o continue patient motivation during these intermediate stages.
remaining after removal of the caries- affected tissue. Fig 1 -79 Teeth were restored 4 weeks after the nonvilal Ieeth were whitened Iafier to encourage better oral hygiene to control plaque formation and achieve proper gingival health. Figs 1-85 and 1-86 Gingival health seen dur
reseclive periodontal surgery). using a direct technique. fiberglass dowels. and a dentin-type composite with high fluorescence. Figs 1-80 and ing a checkup after cementation.
1-81 Master stone cast fabricated using a one-step heavy light impression technique developed from a single-phase. dual material imp res-
35
4
CHAPTER 1
1 -7 6
Fig 1-74 Clinical case o f a 38 - year-old male patient with significant periodontal disease. Metal-ceramic rehabilitation i s uneslhelic i n shape sion of the prepared anterior Ieeth. The right canine has been prepared for a laminate veneer. This was done after the tissues healed. about
and color. and secondary caries is present al l he cervical margins. Figs 1-75 and 1-76 Radiographic evaluation and a diagnostic wax up assist 10 months after periodontal surgery. The proper preparation of the Ieeth and the alignment of their surfaces. in frontal and especially
ed in the formulation of the treatment plan. which included the restoration of the anterior Ieeth after the dental hygiene procedures and occlusal views. are prerequisites for the success of all subsequent stages. both clinical and technical. Fig 1-82 Ceramic rehabilitation o n the
reseclive periodontal treatment. relrealmenl of the root canals. home bleaching treatment for the healthy Ieeth (those stained by tetracycline master stone cast. Fig 1 - 83 Master cast of the preparation for the right canine veneer. with incisal reduction and bull margin. Fig 1-4 Close
treatments. not those involved in the prosthetic rehabilitation) for at least 6 months. and whitening of the nonvital loolh preparations before up of the maxillary left tooth preparations. showing considerable whitening in the most apical areas. which is the most difficult and impor
the preproslhelic reconstruction. Fig 1-77 Marked difference in the color of the tooth preparations after removal of the metal-ceramic tant part of the tooth to conceal with a restoration if there is discoloration. In this phase. the tissues still show slight inflammation. mostly
restorations. This will be resolved by bleaching with hydrogen peroxide 130 vol) lvol 7.6%1 mixed wilh sodium perborale. Fig 1-78 Dentin because of lhe patient's poor oral hygiene regimen. II can be very imporlan l l o continue patient motivation during these intermediate stages.
remaining after removal of the caries- affected tissue. Fig 1 -79 Teeth were restored 4 weeks after the nonvilal Ieeth were whitened Iafier to encourage better oral hygiene to control plaque formation and achieve proper gingival health. Figs 1-85 and 1-86 Gingival health seen dur
reseclive periodontal surgery). using a direct technique. fiberglass dowels. and a dentin-type composite with high fluorescence. Figs 1-80 and ing a checkup after cementation.
1-81 Master stone cast fabricated using a one-step heavy light impression technique developed from a single-phase. dual material imp res-
35
4
CHAPTER 1
igs 1-87 1D 1 -go Clinical situation before and after rehabilitative treatment. fig 1-g 1 At high magnification with a stereomicroscope. we can see. i n an unusual view. the healthy sulcular epithelium.
Fig 1 �g 2 The same clinical view after cementation. revealing I he correct integration of the ceramic crown and the emergence profile with the
g1ng1val marg1n naturally supported.
31
CHAPTER 1
igs 1-87 1D 1 -go Clinical situation before and after rehabilitative treatment. fig 1-g 1 At high magnification with a stereomicroscope. we can see. i n an unusual view. the healthy sulcular epithelium.
Fig 1 �g 2 The same clinical view after cementation. revealing I he correct integration of the ceramic crown and the emergence profile with the
g1ng1val marg1n naturally supported.
31
Figs 1-93 1l 1 -95 Clin1cat dela1ls of the various ceram1c restorations. Note the excellent esthetic integration of the restored crowns. Figs 1-100 to 1-102 Maturation and positive response of the tissues after 1 month. 4 months. and 8 months. respectively. are clear i ndications
of the correct execution of the procedures and the protection of the marginal tissues and the biologic range. which are fundamental for the
Fig 1-96 Frontal mw of one of the restorations at 2 5 x magnifi cation. The marginal !Issue is 1n perfect health. longevity of the clinical result. if properly maintained by the patient.
Figs 1-97 and 1-99 Images of the lateral segment before and after treatment completion. An excellent level of esthetics has been achieved.
Despite a severely compromised in1l1al situation. all the treatments were conducted successfully, fully meeting the expectations of both the
patient and the treatment team.
Fig 1-99 Th1s dela1l view of the smile demonstrates the effect of the 6-month home bleaching treatment with 1 01 carbamide peroxide.
l
Figs 1-93 1l 1 -95 Clin1cat dela1ls of the various ceram1c restorations. Note the excellent esthetic integration of the restored crowns. Figs 1-100 to 1-102 Maturation and positive response of the tissues after 1 month. 4 months. and 8 months. respectively. are clear i ndications
of the correct execution of the procedures and the protection of the marginal tissues and the biologic range. which are fundamental for the
Fig 1-96 Frontal mw of one of the restorations at 2 5 x magnifi cation. The marginal !Issue is 1n perfect health. longevity of the clinical result. if properly maintained by the patient.
Figs 1-97 and 1-99 Images of the lateral segment before and after treatment completion. An excellent level of esthetics has been achieved.
Despite a severely compromised in1l1al situation. all the treatments were conducted successfully, fully meeting the expectations of both the
patient and the treatment team.
Fig 1-99 Th1s dela1l view of the smile demonstrates the effect of the 6-month home bleaching treatment with 1 01 carbamide peroxide.
l
CHAPTER 1
..Desi g n i n g for function a n d esthetics The advent of dental magnification instruments, par
ticularly the stereomicroscope, has made improve
The dental technician plays a key role in the oral ment in quality possible.
rehabilitation process; the quality of the laboratoy To analyze and plan the construction of the pros 1 - 1 04
work determines the success of the interdisciplinary thesis requires a highly cooperative relationship
work and, ultimately, the patient's satisfaction. All between clinician and dental technician as well as
dental professionals should remind themselves how respect for one another's different skills and exper·
important a prosthetic restoration can be to a pa tise. Making the definitive prosthetic restoration a
tient, not only in terms of esthetics but also with success also requires comprehensive initial analysis
regard to its psychological and social impact on his of the case. The prosthetic work is planned by using
or her life. the data gathered i n the diagnostic stage and by
The design of a prosthetic restoration generates consulting with the clinician about the functional
expectations in the patient that may reveal a search and esthetic qualities required for the prosthesis.
for an ideal image and/or conceal more intimate The plan that is developed allows the dental techni
motivations. The clinician and dental technician must, cian to select the optimal technique and materials
despite dificulties, interpret patient expectations for the restoration. Studying the case with a suitable
and motivations from the three-way communication diagnostic waxup enables clinicians to evaluate
with the patient. The aim of the laboratoy is to pro whether the result of the work can satisfy the
duce prosthetic restorations that are precise, esthet patient's esthetic and functional needs (Figs 1-103 to
ic, and occlusally functional. Precision inspires much 1·105).
of the work and is essential to every parameter by Careful examination of extracted natural teeth
which the prosthesis can be measured. When a pros allows for an understanding of the correct crown
thetic restoration integrates perfectly into the com· root relationship and how nature achieves the har T H E RELAT IONS H I P 0 F FOR M AND FUNC T ION
plex biologic system of the oral cavity, the clinician monious esthetic relationship between form and
has balanced function with esthetics, form with ma function (Fig 1-106). This understanding is important
terial, and harmony among all of the variables in play. to professional training. Gleaning such knowledge
The quality of the product cannot be measured from nature through intense learning and practice
only in numeric terms (ie, in microns) nor assessed with a material like wax enables operators to im·
solely through esthetics, but must represent a sym· prove their results. Using special multicolored waxes
biosis of esthetics and function -a reproduction of (eg, Creare Wax, Leach & Dillon), dental technicians
natural characteristics. Clinicians pursue this symbio· can create waxups that give the patient a clearer
sis through meticulous technique, in-depth knowl· idea of the esthetic goals and the type of work to
edge of the materials, and use of interpretive skills. be performed (Fig 1-107). ..
Fig 1 -103 1nilial situation i n a complex clinical case o f a patient suffering from bruxism. analyzed b y means o f two casts mounted i n the artic
ulator to study the various possibilities of clinical technique and dental design. Figs 1-14 and 1-105 The diagnostic waxup can be used to eval
uate the feasibility of the treatment plan. This phase can furnish precise indications from the esthetic and functional standpoints. Fig 1-106
By carefully examining the composition of a natural tooth and ils anatomic details. we can interpret the correct form to function ratio, only
by improving our knowledge will we be able to reproduce the harmony a � d esthetics of the mod ! l .nature has furnished. Fig 1-107 By means of
_
a complete diagnostic waxup using multicolored wax. the dental techn1c1an can prov1de the cliniCian. and above all the patient. more precise
information about the final outcome of the work.
41
CHAPTER 1
..Desi g n i n g for function a n d esthetics The advent of dental magnification instruments, par
ticularly the stereomicroscope, has made improve
The dental technician plays a key role in the oral ment in quality possible.
rehabilitation process; the quality of the laboratoy To analyze and plan the construction of the pros 1 - 1 04
work determines the success of the interdisciplinary thesis requires a highly cooperative relationship
work and, ultimately, the patient's satisfaction. All between clinician and dental technician as well as
dental professionals should remind themselves how respect for one another's different skills and exper·
important a prosthetic restoration can be to a pa tise. Making the definitive prosthetic restoration a
tient, not only in terms of esthetics but also with success also requires comprehensive initial analysis
regard to its psychological and social impact on his of the case. The prosthetic work is planned by using
or her life. the data gathered i n the diagnostic stage and by
The design of a prosthetic restoration generates consulting with the clinician about the functional
expectations in the patient that may reveal a search and esthetic qualities required for the prosthesis.
for an ideal image and/or conceal more intimate The plan that is developed allows the dental techni
motivations. The clinician and dental technician must, cian to select the optimal technique and materials
despite dificulties, interpret patient expectations for the restoration. Studying the case with a suitable
and motivations from the three-way communication diagnostic waxup enables clinicians to evaluate
with the patient. The aim of the laboratoy is to pro whether the result of the work can satisfy the
duce prosthetic restorations that are precise, esthet patient's esthetic and functional needs (Figs 1-103 to
ic, and occlusally functional. Precision inspires much 1·105).
of the work and is essential to every parameter by Careful examination of extracted natural teeth
which the prosthesis can be measured. When a pros allows for an understanding of the correct crown
thetic restoration integrates perfectly into the com· root relationship and how nature achieves the har T H E RELAT IONS H I P 0 F FOR M AND FUNC T ION
plex biologic system of the oral cavity, the clinician monious esthetic relationship between form and
has balanced function with esthetics, form with ma function (Fig 1-106). This understanding is important
terial, and harmony among all of the variables in play. to professional training. Gleaning such knowledge
The quality of the product cannot be measured from nature through intense learning and practice
only in numeric terms (ie, in microns) nor assessed with a material like wax enables operators to im·
solely through esthetics, but must represent a sym· prove their results. Using special multicolored waxes
biosis of esthetics and function -a reproduction of (eg, Creare Wax, Leach & Dillon), dental technicians
natural characteristics. Clinicians pursue this symbio· can create waxups that give the patient a clearer
sis through meticulous technique, in-depth knowl· idea of the esthetic goals and the type of work to
edge of the materials, and use of interpretive skills. be performed (Fig 1-107). ..
Fig 1 -103 1nilial situation i n a complex clinical case o f a patient suffering from bruxism. analyzed b y means o f two casts mounted i n the artic
ulator to study the various possibilities of clinical technique and dental design. Figs 1-14 and 1-105 The diagnostic waxup can be used to eval
uate the feasibility of the treatment plan. This phase can furnish precise indications from the esthetic and functional standpoints. Fig 1-106
By carefully examining the composition of a natural tooth and ils anatomic details. we can interpret the correct form to function ratio, only
by improving our knowledge will we be able to reproduce the harmony a � d esthetics of the mod ! l .nature has furnished. Fig 1-107 By means of
_
a complete diagnostic waxup using multicolored wax. the dental techn1c1an can prov1de the cliniCian. and above all the patient. more precise
information about the final outcome of the work.
41
CHAPTER 1
.. ing and orthogonal guide for attaching the model • Intraoral view showing occlusal contact to assess
.. Preparing the master casts quently polished using a rubber-tipped handpiece
(97641.104.100, Komet) with a sharp instrument to base. This phase is followed by squaring and sub the integration of the incisal margin with the
Implementing a treatment plan requires a prelimi remove any bubbles produced by the i mpression sequent duplication according to the procedures mandibular incisors (Fig 1-126).
nary study using diagnostic waxing. The waxup material (Figs 1-109 to 1-111). The maxillary arch will and methods previously described. • Profile of the lips and the dental arches in occlu
model, which is generally prepared by the dental be positioned on the base of the future cast, and sion (Figs 1-127 to 1-129).
technician, defines the proposed morphology of the the outline will be defined and traced using a • Set of standard collarless ceramic samples (Fig
Photog ra p h i c docu m e ntation
teeth and gingiva on study casts, i n accordance with graphite pencil (Fig 1-112). A number of retention 1·130).
pre-established anatomic and functional parameters. grooves are cut using a coarse-grain separator disk Photographic images facilitate communication of the • System used i n the laboratory with a set of cus
Changes to the patient's initial situation can be directly on the base, inside the graphite outline, and general esthetic and clinical parameters between the tomized ceramic samples (Fig 1-131).
made by subtraction (ie, removing plaster from the on the arch portion (Figs 1-113 and 1-114). clinical ofice and the laboratory. This text focuses • Anterior teeth and their internal and external char
cast) or addition (ie, adding wax to the cast) and by The two parts are joined together by moistening on the type of photographic documentation neces acteristics against a black background (Fig 1-132).
moving teeth, if applicable, to sim ulate the action of them, bonding them with casting plaster for a more say to produce an esthetic restoration prosthesis • Lingual view (Fig 1-133).
orthodontic treatment. When executing this phase. liquid consistency, and removing any excess materi rather than the format. • Close-up intraoral view of the texture and the
the technician follows the clinician's prescription for al before the plaster sets (Figs 1-115 and 1-116). The types of photographs that can be transmit quality of the internal and external characteristics.
extensions, the type of restorative treatment, the Exposing the casts to infrared rays enhances the set ted over a distance, common both to the dental The photographs must be taken with and without
possibilities of appropriate periodontal therapy and/or ting of the plaster. However, the rays must be pro office and to the laboratory, are included in com the black background, which serves to eliminate
orthodontic treatment, if applicable, while also exam duced by a lamp capable of generating heat during plete photographic records, the principal compo reRection and highlight the most important char·
ining the initial slides of the clinical case." the first 15 minutes of the plaster setting. After this nents of which are listed below '3 acteristics and esthetic features (Fig 1-134).
The clinician performs the first procedure by ob setting phase has been completed, the dental techni • Dental preparations, which affect the color quali
taining the initial i mpressions of the case using irre cian can square the cast according to precise geomet • Patient's overall appearance and smile (Figs 1-120 ty of all-ceramic restorations (Fig 1-135).
versible hydrocolloid material. The i mpressions are ric criteria (Fig 1-117). The master cast is then ready and 1-121).
i mmediately sent to the laboratory (ie, within 10 to be duplicated using a 1 : 1 ratio condensation-type • Three degrees of smile: just beginning, a little All of these photographic images are essential to
minutes of being cast with extrahard stone). If the silicone (Figs 1-118 and 1-119). By using a new stone wider, and wide (Figs 1-122 to 1-124). the development of a com plete prosthetic case,
plaster cast cannot be made immediately, or for cast produced from the first silicone duplication cast • Global intraoral view of the dentition (Fig 1-125). whereas photographs o n ly of the patient's face,
cases requiring long-distance cooperation or addi to implement the waxup, the dental technician leaves smile, and overall case are required for preparation
tions, dental technicians can cast with silicone. The the original cast intact and thus is able to deliver of the laboratory diagnostic waxup. ..
dental technician creates study casts of the initial both the cast of the initial case and the diagnostic
i mpression i n the laboratory using a class IV plaster waxup to the clinician.
stone (Fujirock, GO. This cast is developed in two An alternative technique entails first pouring the
phases: part of the plaster mixed under vacuum is tooth-gingival portion; after setting has been com
cast directly in the impression while the remainder is pleted, the cast is trimmed and three holes are
cast in a rubber base readily available on the market. drilled, one in the front and two in the back at the
The gypsum stone cast will set in approximately base of the arch. The holes are precisely calibrated
45 minutes. Once both casts are hardened, they may to the diameter of three pins that are subsequently
be removed from the impression and squared using inserted and bonded with cyanoacrylate. This tech
a squaring tool (Fig 1-108). The tooth-gingival por nique enables the portion of the already-set cast to
tion will be trimmed using super coarse tungsten be positioned on a rubber base filled with casting
carbide burs (H251SA.104.06o, Komet) and subse- plaster. The pins act both as a stop and as a center- ..
3
CHAPTER 1
.. ing and orthogonal guide for attaching the model • Intraoral view showing occlusal contact to assess
.. Preparing the master casts quently polished using a rubber-tipped handpiece
(97641.104.100, Komet) with a sharp instrument to base. This phase is followed by squaring and sub the integration of the incisal margin with the
Implementing a treatment plan requires a prelimi remove any bubbles produced by the i mpression sequent duplication according to the procedures mandibular incisors (Fig 1-126).
nary study using diagnostic waxing. The waxup material (Figs 1-109 to 1-111). The maxillary arch will and methods previously described. • Profile of the lips and the dental arches in occlu
model, which is generally prepared by the dental be positioned on the base of the future cast, and sion (Figs 1-127 to 1-129).
technician, defines the proposed morphology of the the outline will be defined and traced using a • Set of standard collarless ceramic samples (Fig
Photog ra p h i c docu m e ntation
teeth and gingiva on study casts, i n accordance with graphite pencil (Fig 1-112). A number of retention 1·130).
pre-established anatomic and functional parameters. grooves are cut using a coarse-grain separator disk Photographic images facilitate communication of the • System used i n the laboratory with a set of cus
Changes to the patient's initial situation can be directly on the base, inside the graphite outline, and general esthetic and clinical parameters between the tomized ceramic samples (Fig 1-131).
made by subtraction (ie, removing plaster from the on the arch portion (Figs 1-113 and 1-114). clinical ofice and the laboratory. This text focuses • Anterior teeth and their internal and external char
cast) or addition (ie, adding wax to the cast) and by The two parts are joined together by moistening on the type of photographic documentation neces acteristics against a black background (Fig 1-132).
moving teeth, if applicable, to sim ulate the action of them, bonding them with casting plaster for a more say to produce an esthetic restoration prosthesis • Lingual view (Fig 1-133).
orthodontic treatment. When executing this phase. liquid consistency, and removing any excess materi rather than the format. • Close-up intraoral view of the texture and the
the technician follows the clinician's prescription for al before the plaster sets (Figs 1-115 and 1-116). The types of photographs that can be transmit quality of the internal and external characteristics.
extensions, the type of restorative treatment, the Exposing the casts to infrared rays enhances the set ted over a distance, common both to the dental The photographs must be taken with and without
possibilities of appropriate periodontal therapy and/or ting of the plaster. However, the rays must be pro office and to the laboratory, are included in com the black background, which serves to eliminate
orthodontic treatment, if applicable, while also exam duced by a lamp capable of generating heat during plete photographic records, the principal compo reRection and highlight the most important char·
ining the initial slides of the clinical case." the first 15 minutes of the plaster setting. After this nents of which are listed below '3 acteristics and esthetic features (Fig 1-134).
The clinician performs the first procedure by ob setting phase has been completed, the dental techni • Dental preparations, which affect the color quali
taining the initial i mpressions of the case using irre cian can square the cast according to precise geomet • Patient's overall appearance and smile (Figs 1-120 ty of all-ceramic restorations (Fig 1-135).
versible hydrocolloid material. The i mpressions are ric criteria (Fig 1-117). The master cast is then ready and 1-121).
i mmediately sent to the laboratory (ie, within 10 to be duplicated using a 1 : 1 ratio condensation-type • Three degrees of smile: just beginning, a little All of these photographic images are essential to
minutes of being cast with extrahard stone). If the silicone (Figs 1-118 and 1-119). By using a new stone wider, and wide (Figs 1-122 to 1-124). the development of a com plete prosthetic case,
plaster cast cannot be made immediately, or for cast produced from the first silicone duplication cast • Global intraoral view of the dentition (Fig 1-125). whereas photographs o n ly of the patient's face,
cases requiring long-distance cooperation or addi to implement the waxup, the dental technician leaves smile, and overall case are required for preparation
tions, dental technicians can cast with silicone. The the original cast intact and thus is able to deliver of the laboratory diagnostic waxup. ..
dental technician creates study casts of the initial both the cast of the initial case and the diagnostic
i mpression i n the laboratory using a class IV plaster waxup to the clinician.
stone (Fujirock, GO. This cast is developed in two An alternative technique entails first pouring the
phases: part of the plaster mixed under vacuum is tooth-gingival portion; after setting has been com
cast directly in the impression while the remainder is pleted, the cast is trimmed and three holes are
cast in a rubber base readily available on the market. drilled, one in the front and two in the back at the
The gypsum stone cast will set in approximately base of the arch. The holes are precisely calibrated
45 minutes. Once both casts are hardened, they may to the diameter of three pins that are subsequently
be removed from the impression and squared using inserted and bonded with cyanoacrylate. This tech
a squaring tool (Fig 1-108). The tooth-gingival por nique enables the portion of the already-set cast to
tion will be trimmed using super coarse tungsten be positioned on a rubber base filled with casting
carbide burs (H251SA.104.06o, Komet) and subse- plaster. The pins act both as a stop and as a center- ..
3
P R E P A R AT I 0F T STONE CAST CONSTRUCTI ON AND DESIGN OF THE MASTER CAST
Fig 1-108 Maxillary portion of the study cast trimmed using the s q uaring tool. The impression used to implement the cast is executed using a Fig 1-114 Retentions inside the traced outline marked previously by �encil on the base of the future study cast. The. cast b � s e must
class IV plaster. Fig 1-10g Trimming phase carried out using tungsten carbide cutters. This first processing phase involves the removal of all also have retentions to improve the bond between the two parts to be JOined. Fig 1-115 The two parts of the cast are JOined USing plas
the excess material using this type of cutter. which has a more aggressive cut. Fig 1-110 The cast is polished using a rubber-tipped handpiece. ter with a more liquid consisten cy. The time necessary 'or the plaster to set must elapse after the two parts have been joined by
mak1ng � he plaster surface much smoother and more even. F1� 1-111 A very sharp hand tool is used in the interdental sites and on the gingi exerting manual pressure in order to have the opportun�ty to remove the excess matenal. F1g 1-116 Removal of the excess matenal
val port1ons to reduce and remov � the 1mperfect10ns present 1 n the model. which are generally due to minor stretching of the impression or during the plaster setting phase. The work is pe rformed using a sha � p tool that allo_ws the. excess plaster material o n the cast to be
aJr bubbles l�at may be present 1n the impres � ion material. ig 1-112 Marking the peripheral limits of the cast"s maxillary portion using a _
removed more easily. Fig 1-117 Cast squaring. ThiS procedure can be Improved by us10g calibrated tools. The authors prefer to estab
_ way on the surface of the lower
graph �le penc1L The traced Site IS represented 1n thiS base for subsequent implementation of the mechanical lish well-defined geometries for both the maxillary and mandibular casts to ensure a clearer and immediate view of the case to be
retentiOns on 1ls Internal SJle. Fig 1-113 Deep and pronounced grooves are cut in the base of the cast. These grooves must be executed using treated. Fig 1-118 Completed study casts after the various processing phases are ready Ia be duplicated : Fig 1-11Q_ Silicone d_uplica
a coarse-grained separator disk to achieve a satisfactory retention effect. tion using a 1 , 1 ratio. This material requires l hour to . set. The plaster cas! IS removed from the . du � llcat1on ' atenal after thiS pen
ad. and it is necessary to wait 20 minutes before casting the new plaster model InSide the duplication matenal.
5
P R E P A R AT I 0F T STONE CAST CONSTRUCTI ON AND DESIGN OF THE MASTER CAST
Fig 1-108 Maxillary portion of the study cast trimmed using the s q uaring tool. The impression used to implement the cast is executed using a Fig 1-114 Retentions inside the traced outline marked previously by �encil on the base of the future study cast. The. cast b � s e must
class IV plaster. Fig 1-10g Trimming phase carried out using tungsten carbide cutters. This first processing phase involves the removal of all also have retentions to improve the bond between the two parts to be JOined. Fig 1-115 The two parts of the cast are JOined USing plas
the excess material using this type of cutter. which has a more aggressive cut. Fig 1-110 The cast is polished using a rubber-tipped handpiece. ter with a more liquid consisten cy. The time necessary 'or the plaster to set must elapse after the two parts have been joined by
mak1ng � he plaster surface much smoother and more even. F1� 1-111 A very sharp hand tool is used in the interdental sites and on the gingi exerting manual pressure in order to have the opportun�ty to remove the excess matenal. F1g 1-116 Removal of the excess matenal
val port1ons to reduce and remov � the 1mperfect10ns present 1 n the model. which are generally due to minor stretching of the impression or during the plaster setting phase. The work is pe rformed using a sha � p tool that allo_ws the. excess plaster material o n the cast to be
aJr bubbles l�at may be present 1n the impres � ion material. ig 1-112 Marking the peripheral limits of the cast"s maxillary portion using a _
removed more easily. Fig 1-117 Cast squaring. ThiS procedure can be Improved by us10g calibrated tools. The authors prefer to estab
_ way on the surface of the lower
graph �le penc1L The traced Site IS represented 1n thiS base for subsequent implementation of the mechanical lish well-defined geometries for both the maxillary and mandibular casts to ensure a clearer and immediate view of the case to be
retentiOns on 1ls Internal SJle. Fig 1-113 Deep and pronounced grooves are cut in the base of the cast. These grooves must be executed using treated. Fig 1-118 Completed study casts after the various processing phases are ready Ia be duplicated : Fig 1-11Q_ Silicone d_uplica
a coarse-grained separator disk to achieve a satisfactory retention effect. tion using a 1 , 1 ratio. This material requires l hour to . set. The plaster cas! IS removed from the . du � llcat1on ' atenal after thiS pen
ad. and it is necessary to wait 20 minutes before casting the new plaster model InSide the duplication matenal.
5
Figs 1-120 and 1-121 Patient's general appearance and face when smiling. These images are essential to the dental technician to view the Fig 1-127 Lip profile. which highlights the relationship of the lips to their support.
dentofacial structures and their relationships. Figs 1-128 and 1-12g Profile views of the dental arches for analysis of the overjet and overbite situation and the support of the gingival tissues.
igs 1-122 o 1-124 Three different degrees of smile intensity. which serve to help the dental technician understand the dentolabial relation Fig 1-130 Intraoral image of the arches with the standard ceramic samples to establish a general evaluation of the color. This solution enables
ship and the extent the incisors can be modified when implementing the preliminary diagnostic waxup. the general color to be communicated over a distance Without the techn1c1an see1ng the patient.
Fig 1-125 Overall image of lhe leelh to evaluate the anatomic conditions and relationships. This image facilitates the understanding of which Fig 1-131 Same image using a set of customized ceramic samples. enabling a more specific evaluation of the cores to be added during the
points can be a changed with the waxup to improve the final result. ceramic layering procedure.
Fig 1-126 1ntraoral view showing occlusal contact to evaluate the Incisal cores to be used. An image that places the two arches on the same
Fig 1-132 Slide taken using a black background sheet that highlights the incisal effects in the natural dentition.
plane. and therefore achieves the same luminous reflection. helps to harmonize the colorimetric relationship of the final prosthesis more
effectively. Fig 1-133 Lingual view provides additional information to achieve the best. possible chromatic resuU during the stratification procedure.
However. the authors use a smaller number of ceramic cores 1n thiS Site. wh1ch IS less Important esthetically compared With the buccal Site.
47
Figs 1-120 and 1-121 Patient's general appearance and face when smiling. These images are essential to the dental technician to view the Fig 1-127 Lip profile. which highlights the relationship of the lips to their support.
dentofacial structures and their relationships. Figs 1-128 and 1-12g Profile views of the dental arches for analysis of the overjet and overbite situation and the support of the gingival tissues.
igs 1-122 o 1-124 Three different degrees of smile intensity. which serve to help the dental technician understand the dentolabial relation Fig 1-130 Intraoral image of the arches with the standard ceramic samples to establish a general evaluation of the color. This solution enables
ship and the extent the incisors can be modified when implementing the preliminary diagnostic waxup. the general color to be communicated over a distance Without the techn1c1an see1ng the patient.
Fig 1-125 Overall image of lhe leelh to evaluate the anatomic conditions and relationships. This image facilitates the understanding of which Fig 1-131 Same image using a set of customized ceramic samples. enabling a more specific evaluation of the cores to be added during the
points can be a changed with the waxup to improve the final result. ceramic layering procedure.
Fig 1-126 1ntraoral view showing occlusal contact to evaluate the Incisal cores to be used. An image that places the two arches on the same
Fig 1-132 Slide taken using a black background sheet that highlights the incisal effects in the natural dentition.
plane. and therefore achieves the same luminous reflection. helps to harmonize the colorimetric relationship of the final prosthesis more
effectively. Fig 1-133 Lingual view provides additional information to achieve the best. possible chromatic resuU during the stratification procedure.
However. the authors use a smaller number of ceramic cores 1n thiS Site. wh1ch IS less Important esthetically compared With the buccal Site.
47
CHAPTER 1
• Diag nostic waxup (eg, gingival and/or ridge remodeling, orthodontic

treatment), the tooth preparation, and any provi
Once the study casts have been poured, the techni sional restorative treatment corresponding to the
cal or laboratory treatment plan can be developed new situation.
to define the functional and esthetic restoration. The waxup, which is executed by applying mono
This is the opportunity for the dental technician chromatic wax (white or gray) on the plaster stone
to adjust the esthetics to fit the patient's personali cast, provides the patient with a n idea of the pro
ty and to determine the best technique for the situ posed restoration and the appearance23 of the
ation.22 The level of creative contribution depends veneers. 24
on the type of treatment. Restorative objectives must be defined in this
The creativity involved in restoring one or two first phase of the diagnostic approach. The techni
anterior teeth is significantly reduced when the in cian can better understand the patient's expecta
tact homologous contralaterals can serve as an es tions by analyzing the patient's requests and charac
thetic reference. This does not make the work less ter and using intuition. During the execution of the
difficult, however, since significant creativity is re diagnostic waxup, the technician can use the proxi
quired to stratify the restoration, and because the
inal result will be compared directly with the adja
mal vertical ridges to determine the placement of
vertical lobes and the subsequent modeling of tooth
P AT I E N T A N A LY S I S P H O T O G R A P H I C D O C U M E N TA T I O N
cent tooth (Figs 1-136 and 1-139). shape. I n the second stage, the dental technician re
Restorations involving two homologous anterior creates the surfaces of the vetical lobes and devel
teeth provide greater creativity with regard to the ops the horizontal lines that deine the second and
shape and position of the teeth. When the dental third layers of the enamel.25
technician is recreating the central incisors, for The technique for tooth buildup of the diagnos
example, the creative scope is only partially limited tic waxup is chosen depending on the requirements
by the presence of adjacent and opposing teeth of the restoration. Additive waxup 26 is appropriate
(Figs 1-140 and 1-141). when the restoration uses bonding techniques and
For restoration of a complete anterior segment, requires redefining the veneers and the labial
the dental technician must redefine the shape, the spacing of the teeth. The technician simply applies
position, and the space distribution for each tooth. wax on the plaster teeth of the study cast to build
This situation requires the highest level of creativity up the shape and the length of the veneers (Figs 1·
of the dental technician (Figs 1-142 to 1-147). 148 to 1-154).
Using the diagnostic waxup, the dental technician Plaster veneer waxup'4 is appropriate for ceram
can redeine the relationships between the dental ic fixed partial dentures and crowns that call for
arches and the inside of the single arch. The waxup restoration of all tooth surfaces, and not just the
determines the preprosthetic preparation, the neces labial surface, as i n the case of ceramic veneers.
sity of implementing other treatment operations
Fig 1-134 Images must also provide information concerning the surface texture and the internal and external chromatic char
acterizations. In fact. these represent crucial factors for the outcome of the prosthetic restorative treatment. s1nce they are
closely associated with the characteristics of the anatomic shape and the chromatic appearance of the teeth.
Fig 1-135 1mage of the prosthetic preparations of the denttion. This ! mage provides significant info_rmation. parti cularly with
all-ceramic restorations. where the color of the prosthetic preparations IS an Integral part of the final outcome.
"
CHAPTER 1
• Diag nostic waxup (eg, gingival and/or ridge remodeling, orthodontic

treatment), the tooth preparation, and any provi
Once the study casts have been poured, the techni sional restorative treatment corresponding to the
cal or laboratory treatment plan can be developed new situation.
to define the functional and esthetic restoration. The waxup, which is executed by applying mono
This is the opportunity for the dental technician chromatic wax (white or gray) on the plaster stone
to adjust the esthetics to fit the patient's personali cast, provides the patient with a n idea of the pro
ty and to determine the best technique for the situ posed restoration and the appearance23 of the
ation.22 The level of creative contribution depends veneers. 24
on the type of treatment. Restorative objectives must be defined in this
The creativity involved in restoring one or two first phase of the diagnostic approach. The techni
anterior teeth is significantly reduced when the in cian can better understand the patient's expecta
tact homologous contralaterals can serve as an es tions by analyzing the patient's requests and charac
thetic reference. This does not make the work less ter and using intuition. During the execution of the
difficult, however, since significant creativity is re diagnostic waxup, the technician can use the proxi
quired to stratify the restoration, and because the
inal result will be compared directly with the adja
mal vertical ridges to determine the placement of
vertical lobes and the subsequent modeling of tooth
P AT I E N T A N A LY S I S P H O T O G R A P H I C D O C U M E N TA T I O N
cent tooth (Figs 1-136 and 1-139). shape. I n the second stage, the dental technician re
Restorations involving two homologous anterior creates the surfaces of the vetical lobes and devel
teeth provide greater creativity with regard to the ops the horizontal lines that deine the second and
shape and position of the teeth. When the dental third layers of the enamel.25
technician is recreating the central incisors, for The technique for tooth buildup of the diagnos
example, the creative scope is only partially limited tic waxup is chosen depending on the requirements
by the presence of adjacent and opposing teeth of the restoration. Additive waxup 26 is appropriate
(Figs 1-140 and 1-141). when the restoration uses bonding techniques and
For restoration of a complete anterior segment, requires redefining the veneers and the labial
the dental technician must redefine the shape, the spacing of the teeth. The technician simply applies
position, and the space distribution for each tooth. wax on the plaster teeth of the study cast to build
This situation requires the highest level of creativity up the shape and the length of the veneers (Figs 1·
of the dental technician (Figs 1-142 to 1-147). 148 to 1-154).
Using the diagnostic waxup, the dental technician Plaster veneer waxup'4 is appropriate for ceram
can redeine the relationships between the dental ic fixed partial dentures and crowns that call for
arches and the inside of the single arch. The waxup restoration of all tooth surfaces, and not just the
determines the preprosthetic preparation, the neces labial surface, as i n the case of ceramic veneers.
sity of implementing other treatment operations
Fig 1-134 Images must also provide information concerning the surface texture and the internal and external chromatic char
acterizations. In fact. these represent crucial factors for the outcome of the prosthetic restorative treatment. s1nce they are
closely associated with the characteristics of the anatomic shape and the chromatic appearance of the teeth.
Fig 1-135 1mage of the prosthetic preparations of the denttion. This ! mage provides significant info_rmation. parti cularly with
all-ceramic restorations. where the color of the prosthetic preparations IS an Integral part of the final outcome.
"
l
CHAPTER 1
Managing the Treatment Plan with the Prosthetic Team J
igs 1-136 D 1-13g Status before (Figs 1 - 1 3 6 and 1 - 1 381 and after (Figs 1 - 1 37 and 1 - 1 39) the bond-type cementation of two different cases. Figs 1-142 and 1-143 When restoring an entire maxillary segment. the essential requirement is to re-create the parameters that relate not only
The first case shows a single fetdspathiC ceramic veneer. and the second shows the restorative treatment of two teeth. The two different clin to the shape and position of the teeth. but also to the division of the space for each tooth.
ical situations both have homologous intact contralateral teeth. The level of creativity is minimal and focus is on the shape of the contralat Figs 1-144 and 1-145 Clinical case involving the complete redefinition of the maxillary anterior segment. The creative level is at a maximum.
eral and its characterization and color. with clear instructions not to modify the initial situation. and the dental technician must interpret the patient"s requirements and needs.
igs 1-10 and 1 -141 Clinical case of ceramic restorative treatment of two homologous teeth. This clinical situation provides greater creativi Figs 1-146 and 1-147 Initial and final smile of a complete redefinition of the anterior segment.
ty to the dental technician in relation to the shape and spatial position of the teeth involved in the restoration.
o 51
l
CHAPTER 1
Managing the Treatment Plan with the Prosthetic Team J
igs 1-136 D 1-13g Status before (Figs 1 - 1 3 6 and 1 - 1 381 and after (Figs 1 - 1 37 and 1 - 1 39) the bond-type cementation of two different cases. Figs 1-142 and 1-143 When restoring an entire maxillary segment. the essential requirement is to re-create the parameters that relate not only
The first case shows a single fetdspathiC ceramic veneer. and the second shows the restorative treatment of two teeth. The two different clin to the shape and position of the teeth. but also to the division of the space for each tooth.
ical situations both have homologous intact contralateral teeth. The level of creativity is minimal and focus is on the shape of the contralat Figs 1-144 and 1-145 Clinical case involving the complete redefinition of the maxillary anterior segment. The creative level is at a maximum.
eral and its characterization and color. with clear instructions not to modify the initial situation. and the dental technician must interpret the patient"s requirements and needs.
igs 1-10 and 1 -141 Clinical case of ceramic restorative treatment of two homologous teeth. This clinical situation provides greater creativi Figs 1-146 and 1-147 Initial and final smile of a complete redefinition of the anterior segment.
ty to the dental technician in relation to the shape and spatial position of the teeth involved in the restoration.
o 51
T
Managing the Treatment Plan with the Prosthetic Team ]
F1gs 1-148 and 1-149 Study of dental anatomy 1n a clinical restoration of the four maxillary incisors. The clinical requirement is to redefine .. After carefully reviewing the intact dentition i n ed with the addition of new wax, particularly in the
the relationships between the arches and advance a possible outcome in wax. Fig 1-150 Additive waxup during the laboratory phases. Note extrahard plaster, the most appropriate are used to palatal aspect (Fig 1-156).
the posil1on of the vertical proximal ridgu in a structural detail and the implementation of the incisal cones and the central lobe. Fig 1-151
Wax anatomy completed. The black linu highlight the position of the ridges and the tooth's macrogeography. This phase is implemented by prepare labial wax veneers (gray wax), which can be This method ensures a natural waxup regardless
us1ng a le Cron-lype Instrument to model the surfaces of the vertical lobes and the horizontal lines. Figs 1-152 and 1-153 Final view of the of the operator's artistic talent; furthermore, the
stored in a repository of age- and gender-specific
modeling 1n frontal and occlusal views The need to restore the labial anatomy can be noted from the occlusal view. especially if a com par
liOn is made Wllh the homologous contralateral. F1g 1-14 Diagnostic waxing completed. This diagnostic study can influence the preproslhei veneers for use in future clinical cases. Wax technique saves a significant amount of time over
IC phase. and 1f applicable. can lead to such treatment as chang1ng the gingival contours or orthodontic treatment. among others. Fig 1-155
veneers can be positioned directly on casts (Fig 1· the traditional methods requiring a full restoration
Wuup Implemented with the help of wax veneers. The veneers are positioned on the reduced Ieeth of the plaster cast. The wax veneer is
bonded to the plaster site USing spent wax. Fig 1-156 Overall diagnostic waxing completed. using stored wax veneers. This technique differs 155) once the elements to be restored have been to be made using wax (ie, full waxup).27 ,
from a trad111onal d1agnoshc waxing in which a 11ngle wax veneer is modeled for each tooth, one by one. By contrast. this method saves lime.
but a cert11n degrn of care is reqUired to add wax and customize changes to improve and personalize the veneer shapes. reduced in size and their shape has been complet-
52 3
T
Managing the Treatment Plan with the Prosthetic Team ]
F1gs 1-148 and 1-149 Study of dental anatomy 1n a clinical restoration of the four maxillary incisors. The clinical requirement is to redefine .. After carefully reviewing the intact dentition i n ed with the addition of new wax, particularly in the
the relationships between the arches and advance a possible outcome in wax. Fig 1-150 Additive waxup during the laboratory phases. Note extrahard plaster, the most appropriate are used to palatal aspect (Fig 1-156).
the posil1on of the vertical proximal ridgu in a structural detail and the implementation of the incisal cones and the central lobe. Fig 1-151
Wax anatomy completed. The black linu highlight the position of the ridges and the tooth's macrogeography. This phase is implemented by prepare labial wax veneers (gray wax), which can be This method ensures a natural waxup regardless
us1ng a le Cron-lype Instrument to model the surfaces of the vertical lobes and the horizontal lines. Figs 1-152 and 1-153 Final view of the of the operator's artistic talent; furthermore, the
stored in a repository of age- and gender-specific
modeling 1n frontal and occlusal views The need to restore the labial anatomy can be noted from the occlusal view. especially if a com par
liOn is made Wllh the homologous contralateral. F1g 1-14 Diagnostic waxing completed. This diagnostic study can influence the preproslhei veneers for use in future clinical cases. Wax technique saves a significant amount of time over
IC phase. and 1f applicable. can lead to such treatment as chang1ng the gingival contours or orthodontic treatment. among others. Fig 1-155
veneers can be positioned directly on casts (Fig 1· the traditional methods requiring a full restoration
Wuup Implemented with the help of wax veneers. The veneers are positioned on the reduced Ieeth of the plaster cast. The wax veneer is
bonded to the plaster site USing spent wax. Fig 1-156 Overall diagnostic waxing completed. using stored wax veneers. This technique differs 155) once the elements to be restored have been to be made using wax (ie, full waxup).27 ,
from a trad111onal d1agnoshc waxing in which a 11ngle wax veneer is modeled for each tooth, one by one. By contrast. this method saves lime.
but a cert11n degrn of care is reqUired to add wax and customize changes to improve and personalize the veneer shapes. reduced in size and their shape has been complet-
52 3
CHAPTER 1
Managing the Treatment Plan w1th the Prosthetic Team
..Si licone i n dex prevent the undesired tendency for the crowns to in
crease in length after the reduction procedure.
After completing the waxup, the dental technician The silicone index also can serve as a guide for
prepares at least three silicone indices to be for the clinician when redefining an anterior arch seg
warded to the dental office. Two indices are sec ment. When orthodontic movement for esthetic and
tioned on the vertical or horizontal plane for use i n preprosthetic purposes is planned prior to the diag FIG 1 - 1 57
checking t h e space of t h e oral cavity during the nostic waxup, the silicone index helps identify the
preparatory phases. The third index enables the clin correct dental position. Therefore, after completing
ician to prepare a provisional prosthesis (if needed) the waxup based on ideal position, the dental tech
directly in the oral cavity using acrylic resin. When nician must provide the orthodontist with a silicone
communication with the dental office must be com index of the palatal-incisal shape that can verify any
pleted, the dental technician can provide a fourth dental displacements made in relation to the most
index, sectioned occlusally, to extend the immediate appropriate position. The palatal-incisal shape must
view of the buccal and lingual sites of the prepared be in the center of the mold to help the operator fol
teeth (Fig 1-15 7). low the technical details as closely as possible (Figs
The silicone index also facilitates other important 1-158 and 1-159). This also allows for the possibility
procedures, for example, by guiding the dentist to of implementing a classic setup beforehand and
FIG l - 1 58 FIG 1-159
reduce the teeth without distorting their position or adapting the palatal-incisal silicone index to it. Once
length. This index is prepared using silicone and has positioned i n the oral cavity, the index will verify
a positioning and centering function. Care must be that the dentition displaced through orthodontic
taken to section the index only on the middle third treatment will achieve the position closest to the
when the preparation has been completed and is in
position o n the plaster cast. The silicone index in
treatment plan (Figs 1-160 and 1-161).
In this case the setup has the same morphology
S I L I C O N E I N 0 E X C O M M U N I C AT I O N T 0 0 l
cludes the provisional crowns as well as the occlusal as the natural teeth, and the correct orthodontic
information of the immediately adjacent teeth. The position is verified when the optimum joint. or the
occlusal stops on the adjacent teeth provide a sta· nearest possible position, is achieved i n the sili-
ble position and centering reference and, above all, cone index. ..
Fig 1-157 Th1s Silicone 1ndu. labmated in the laboratory d�reclly on I he diagnostic waxing. IS des1gned alter the appropriate
homontal cut to prov1de a pos11ion1ng gu1de.
Fig 1-158 Completed d11gnost1c wax up The shape ond anatomy have been established by the dental technician based on clin
Ical prescr1pt1on
Fig 1-1sg The cliniCian uses the siliCone 1ndn directly 1n the mouth during orthodontic movement. The aim is to recenler the
new pos11ion of the denllllon 1n accordance w1th the information prov1ded in the planning phase of the diagnostic waxup lor
the prosthetiC preparollon phase.
Fi g 1 10 S i l i cone index pos1t1oned on the setup model This tool helps the orthodontist to evaluate the orthodontic treatment
to be 1mplemenlld The correct pos1t1on of the dent11ion must be established following the orthodontic treatment to achieve a FIG 1 -160 FIG 1-161
satiSfactory esthetic ruu ll
F1g 1 161 Extra hard silicone 1ndn inserted 1n the oral cav1ty dunng the rtcenterlng phase to enable the clinician to mw the
1dul poSition of the restored elements ThiS procedure w1ll help the operator to 1mplemenl the d11gnost1t plan as p r eme l y
I I pOSSible
5
CHAPTER 1
Managing the Treatment Plan w1th the Prosthetic Team
..Si licone i n dex prevent the undesired tendency for the crowns to in
crease in length after the reduction procedure.
After completing the waxup, the dental technician The silicone index also can serve as a guide for
prepares at least three silicone indices to be for the clinician when redefining an anterior arch seg
warded to the dental office. Two indices are sec ment. When orthodontic movement for esthetic and
tioned on the vertical or horizontal plane for use i n preprosthetic purposes is planned prior to the diag FIG 1 - 1 57
checking t h e space of t h e oral cavity during the nostic waxup, the silicone index helps identify the
preparatory phases. The third index enables the clin correct dental position. Therefore, after completing
ician to prepare a provisional prosthesis (if needed) the waxup based on ideal position, the dental tech
directly in the oral cavity using acrylic resin. When nician must provide the orthodontist with a silicone
communication with the dental office must be com index of the palatal-incisal shape that can verify any
pleted, the dental technician can provide a fourth dental displacements made in relation to the most
index, sectioned occlusally, to extend the immediate appropriate position. The palatal-incisal shape must
view of the buccal and lingual sites of the prepared be in the center of the mold to help the operator fol
teeth (Fig 1-15 7). low the technical details as closely as possible (Figs
The silicone index also facilitates other important 1-158 and 1-159). This also allows for the possibility
procedures, for example, by guiding the dentist to of implementing a classic setup beforehand and
FIG l - 1 58 FIG 1-159
reduce the teeth without distorting their position or adapting the palatal-incisal silicone index to it. Once
length. This index is prepared using silicone and has positioned i n the oral cavity, the index will verify
a positioning and centering function. Care must be that the dentition displaced through orthodontic
taken to section the index only on the middle third treatment will achieve the position closest to the
when the preparation has been completed and is in
position o n the plaster cast. The silicone index in
treatment plan (Figs 1-160 and 1-161).
In this case the setup has the same morphology
S I L I C O N E I N 0 E X C O M M U N I C AT I O N T 0 0 l
cludes the provisional crowns as well as the occlusal as the natural teeth, and the correct orthodontic
information of the immediately adjacent teeth. The position is verified when the optimum joint. or the
occlusal stops on the adjacent teeth provide a sta· nearest possible position, is achieved i n the sili-
ble position and centering reference and, above all, cone index. ..
Fig 1-157 Th1s Silicone 1ndu. labmated in the laboratory d�reclly on I he diagnostic waxing. IS des1gned alter the appropriate
homontal cut to prov1de a pos11ion1ng gu1de.
Fig 1-158 Completed d11gnost1c wax up The shape ond anatomy have been established by the dental technician based on clin
Ical prescr1pt1on
Fig 1-1sg The cliniCian uses the siliCone 1ndn directly 1n the mouth during orthodontic movement. The aim is to recenler the
new pos11ion of the denllllon 1n accordance w1th the information prov1ded in the planning phase of the diagnostic waxup lor
the prosthetiC preparollon phase.
Fi g 1 10 S i l i cone index pos1t1oned on the setup model This tool helps the orthodontist to evaluate the orthodontic treatment
to be 1mplemenlld The correct pos1t1on of the dent11ion must be established following the orthodontic treatment to achieve a FIG 1 -160 FIG 1-161
satiSfactory esthetic ruu ll
F1g 1 161 Extra hard silicone 1ndn inserted 1n the oral cav1ty dunng the rtcenterlng phase to enable the clinician to mw the
1dul poSition of the restored elements ThiS procedure w1ll help the operator to 1mplemenl the d11gnost1t plan as p r eme l y
I I pOSSible
5
CHAPTER 1
� CO M MU N I CATI N G WITH T H E As the clinician listens, the patient's ideas are, in � · Restoration involves the integration of missing U n d e rsta n di n g the psychological
PATI E NT turn, subjected to personal interpretation that may teeth and a partial change in appearance (if aspect
change the real request. The same problem is re applicable) and in the dental parameters.
peated when the clinician communicates the con · Redeinition is a re-evaluation and correction of The patient should be given both verbal explana
Dental tech n ician-patient re lationships
cepts to the dental technician. The dental technician missing teeth to re-establish harmony that can be tions and visual examples of treatment possibilities
The sophisticated techniques of esthetic restoration must further interpret the information according to integrated with the patient's overall appearance. to maximize the likelihood for success i n the esthet
require the participation of a highly qualified team personal perception, and must also take into • An ideal relationship can be established between ic outcome of the treatment and to reduce the pos
of dental technicians. The patient should understand account any practical limitations. Restorative treat the patient and the prosthetic team, which in turn sibility that the patient will be disappointed. It is
the laboratory phase of the treatment as well. For ment incurs all the risks associated with having a can enhance the interaction between the clinician important to understand the patient's social culture
this reason, the patient should be presented to the predominantly esthetic impact, including failure to and technician. and any esthetic touchstones (frequently associated
dental technician early in the treatment. A good rela meet the patient's requests and expectations. • Direct interpersonal contact gives the technician with the prevailing fashion) that influence his or her
tionship should be established based on trust and This traditional method must be used for long the opportunity to make a visual assessment of perception of oral esthetics. In discussing dental es
cooperation, which the professionalism of the pros distance communication between the clinician and the the patient and gives the patient the opportunity thetics, the team should explain that the formulae
thetic team can foster. This first meeting between dental technician. Especially in cases of esthetic redef to express ideas about restorative treatment for proportional esthetics can hinder creativity and
the dental technician and the patient should provide inition, the clinician must work with the patient to directly to the dental technician. that symmety is not always a synonym for harmony.
the patient with a better understanding of the determine any psychological aspect and send a clin Indeed, symmetry may cause tension and disharmo
prosthodontic aspect and the proposed treatment ical prescription and status photos to the technician. In addition to these potential benefits, the distortion ny if introduced in an asymmetric context. Examples
plan. Subsequent communication between the den The clinician and dental technician should know that occurs when information is relayed and inter of plaster stone casts of intact dentitions and photo·
tal technician and patient develops during the diag each other vey well in terms of one another's pro preted is reduced or eliminated. graphs or slides of the cases treated by the team help
nostic phase i n one of two ways.'J cedures and overall work, so that they can achieve Nevertheless. the principal dificulty experienced the patient better u nderstand objective esthetics.
esthetic results while avoiding the aforementioned by the technician, namely the faithful reproduction The clinician-dental technician relationship re
Indirct communication, Patient to dentist to problems. of details he or she has recorded mentally through quires cooperation between two professionals whose
dental tchnician
meetings with the patient, remains. The technician skills are constantly tested in their daily work. When
In the traditional approach, the patient expresses Dirct communication, Patient to dental must be able to differentiate between what can and one of them sufers a restorative failure and tries to
esthetic requirements to the clinician, who then tchnician what cannot be achieved. Likewise, patients must regain the trust of the other, psychological factors
communicates them to the laboratory. Since several A more recent and, undoubtedly, more profitable understand that their expectations cannot exceed pose a significant challenge to the relationship.
communications are involved, this method can in solution is direct communication between the pa realistic esthetic objectives, which are limited by The team can demonstrate its ability to achieve
crease the risk of distorting the original ideas. tient and dental technician, with the possibility of complications (eg, a significant lack of bone, serious desired esthetic results by showing the patient pre
Patients often have a mental image of the smile subsequent visits with the patient. oral disorders, bad positioning of the teeth). In less and postrestorative treatment images from past cases
they desire based on culture, personality, and facial There are many potential benefits to having the complex cases, the technician can gather essential (Figs 1-16z to 1-164).'8 A combined effort should be
expression. However, this image frequently does not dental technician meet with the patient. information by viewing a video or slides or by com made to discourage "Hollywood"-type esthetics; i n
correspond to their actual needs. In addition, a municating over the Internet through videoconfer stead, a more natural expression can be encouraged
request for improved oral esthetics may stem from a • The dental technician is given direct access to by helping patients understand and accept the har
encing software. In restorations that entail copying
failure to accept himself or herself and, therefore, information that i nfluences three levels of creativ a single tooth, the dental technician's expert eye can mony of the esthetics of their personal appearance.
can have psychological implications. Even as the ity (in order of dificulty): copying, restoration, and identify the chroma and color saturation of the soft Dental technicians and clinicians can use efective
patient expresses his or her own image of re redefinition. tissues and the luminosity, character, and translu communication to help patients overcome their ini-
storative treatment to the dentist, there is a certain · Copying i nvolves the integration of one or more cent and transparent features of the teeth using tial doubts and misconceptions. ..
distortion inherent in this first image and the pa intercalated teeth starting from one or more these Indirect aids.
tient's ideas. existing reference teeth. ..
7
CHAPTER 1
� CO M MU N I CATI N G WITH T H E As the clinician listens, the patient's ideas are, in � · Restoration involves the integration of missing U n d e rsta n di n g the psychological
PATI E NT turn, subjected to personal interpretation that may teeth and a partial change in appearance (if aspect
change the real request. The same problem is re applicable) and in the dental parameters.
peated when the clinician communicates the con · Redeinition is a re-evaluation and correction of The patient should be given both verbal explana
Dental tech n ician-patient re lationships
cepts to the dental technician. The dental technician missing teeth to re-establish harmony that can be tions and visual examples of treatment possibilities
The sophisticated techniques of esthetic restoration must further interpret the information according to integrated with the patient's overall appearance. to maximize the likelihood for success i n the esthet
require the participation of a highly qualified team personal perception, and must also take into • An ideal relationship can be established between ic outcome of the treatment and to reduce the pos
of dental technicians. The patient should understand account any practical limitations. Restorative treat the patient and the prosthetic team, which in turn sibility that the patient will be disappointed. It is
the laboratory phase of the treatment as well. For ment incurs all the risks associated with having a can enhance the interaction between the clinician important to understand the patient's social culture
this reason, the patient should be presented to the predominantly esthetic impact, including failure to and technician. and any esthetic touchstones (frequently associated
dental technician early in the treatment. A good rela meet the patient's requests and expectations. • Direct interpersonal contact gives the technician with the prevailing fashion) that influence his or her
tionship should be established based on trust and This traditional method must be used for long the opportunity to make a visual assessment of perception of oral esthetics. In discussing dental es
cooperation, which the professionalism of the pros distance communication between the clinician and the the patient and gives the patient the opportunity thetics, the team should explain that the formulae
thetic team can foster. This first meeting between dental technician. Especially in cases of esthetic redef to express ideas about restorative treatment for proportional esthetics can hinder creativity and
the dental technician and the patient should provide inition, the clinician must work with the patient to directly to the dental technician. that symmety is not always a synonym for harmony.
the patient with a better understanding of the determine any psychological aspect and send a clin Indeed, symmetry may cause tension and disharmo
prosthodontic aspect and the proposed treatment ical prescription and status photos to the technician. In addition to these potential benefits, the distortion ny if introduced in an asymmetric context. Examples
plan. Subsequent communication between the den The clinician and dental technician should know that occurs when information is relayed and inter of plaster stone casts of intact dentitions and photo·
tal technician and patient develops during the diag each other vey well in terms of one another's pro preted is reduced or eliminated. graphs or slides of the cases treated by the team help
nostic phase i n one of two ways.'J cedures and overall work, so that they can achieve Nevertheless. the principal dificulty experienced the patient better u nderstand objective esthetics.
esthetic results while avoiding the aforementioned by the technician, namely the faithful reproduction The clinician-dental technician relationship re
Indirct communication, Patient to dentist to problems. of details he or she has recorded mentally through quires cooperation between two professionals whose
dental tchnician
meetings with the patient, remains. The technician skills are constantly tested in their daily work. When
In the traditional approach, the patient expresses Dirct communication, Patient to dental must be able to differentiate between what can and one of them sufers a restorative failure and tries to
esthetic requirements to the clinician, who then tchnician what cannot be achieved. Likewise, patients must regain the trust of the other, psychological factors
communicates them to the laboratory. Since several A more recent and, undoubtedly, more profitable understand that their expectations cannot exceed pose a significant challenge to the relationship.
communications are involved, this method can in solution is direct communication between the pa realistic esthetic objectives, which are limited by The team can demonstrate its ability to achieve
crease the risk of distorting the original ideas. tient and dental technician, with the possibility of complications (eg, a significant lack of bone, serious desired esthetic results by showing the patient pre
Patients often have a mental image of the smile subsequent visits with the patient. oral disorders, bad positioning of the teeth). In less and postrestorative treatment images from past cases
they desire based on culture, personality, and facial There are many potential benefits to having the complex cases, the technician can gather essential (Figs 1-16z to 1-164).'8 A combined effort should be
expression. However, this image frequently does not dental technician meet with the patient. information by viewing a video or slides or by com made to discourage "Hollywood"-type esthetics; i n
correspond to their actual needs. In addition, a municating over the Internet through videoconfer stead, a more natural expression can be encouraged
request for improved oral esthetics may stem from a • The dental technician is given direct access to by helping patients understand and accept the har
encing software. In restorations that entail copying
failure to accept himself or herself and, therefore, information that i nfluences three levels of creativ a single tooth, the dental technician's expert eye can mony of the esthetics of their personal appearance.
can have psychological implications. Even as the ity (in order of dificulty): copying, restoration, and identify the chroma and color saturation of the soft Dental technicians and clinicians can use efective
patient expresses his or her own image of re redefinition. tissues and the luminosity, character, and translu communication to help patients overcome their ini-
storative treatment to the dentist, there is a certain · Copying i nvolves the integration of one or more cent and transparent features of the teeth using tial doubts and misconceptions. ..
distortion inherent in this first image and the pa intercalated teeth starting from one or more these Indirect aids.
tient's ideas. existing reference teeth. ..
7
CHAPTER 1
� COLOR M ATC H I N G color, particularly for restorations involving single

units or interconnected units in groups of two.
Color matching, in the authors' opinion, should be Based on professional experience, the authors
carried out by the dental technician. Since the tech· believe that the success of an anterior restoration of
nician will perform the stratification to obtain the four or six adjacent teeth is not strictly limited to the
ceramic element, he or she should also interpret the esthetic quality of the definitive color. This is not to
color information from the patient's ceramic cores say that the colorimetric aspect is unimportant, only
and attributes, if applicable. If the technician is un· that the technician also must focus on the shape of FIG 1-162
able to meet the patient in person, however, the the ceramic tooth to achieve the best result.
clinician must undetake the responsibility of trans· The authors have found the use of codes makes
ferring as much information as possible through it easier to communicate color over a distance. The
drawings as well as photographs. color from the cervical third to the middle third of
the tooth has one code, and that from the middle
third to the incisal third of the tooth has another
Photographic considerations
code (Figs 1-165a and 1-16sb). The laboratory can
Photographic documentation can be shared between i nterpret the coded color information provided by
the dental ofice and laboratory, providing that the the prosthodontist for numerous ceramic cores to
same (or similar) photographic system is used. develop a dynamic stratification solution (Fig 1-166).
Some photographs should be prepared in the labo· To attain reliable color identification:
ratory so that the dental technician can accurately
record the dynamic features of color, which are 1. Select the guide samples that most closely match
essential to the stratification process and depend on the available colors (eg, Vita, lvoclar). Position
personal visual perception. At present, certain visu· them on the same plane as the reference teeth,
al details still cannot be communicated precisely with the reference dentition in full view, and pho·
FIG 1-163
through photography because of the nuances of tograph the image. ..
fig 1-162 Examples of natural dentitions can be an excellent way of communicating esthetics to the patient. Visual examples
improve the efficacy of the communication. above all from the psychological aspect. and help the clinician to obtain patient
consent and acceptance of the esthetic concepts.
fig 1-163 Esthetic parameters are established by analyzing the examples of the wax models with the patient and comparing
them to the diagnostic wax up of the case. Cooperation and direct communication must exist between the dental technician and
the pat1ent.
ig 1-14 Technician showin g cases previously treated by the prosthetic team and explaining the esthetic potential of the den
tition and a possible restorative treatment.
FIG 1-164
8
CHAPTER 1
� COLOR M ATC H I N G color, particularly for restorations involving single

units or interconnected units in groups of two.
Color matching, in the authors' opinion, should be Based on professional experience, the authors
carried out by the dental technician. Since the tech· believe that the success of an anterior restoration of
nician will perform the stratification to obtain the four or six adjacent teeth is not strictly limited to the
ceramic element, he or she should also interpret the esthetic quality of the definitive color. This is not to
color information from the patient's ceramic cores say that the colorimetric aspect is unimportant, only
and attributes, if applicable. If the technician is un· that the technician also must focus on the shape of FIG 1-162
able to meet the patient in person, however, the the ceramic tooth to achieve the best result.
clinician must undetake the responsibility of trans· The authors have found the use of codes makes
ferring as much information as possible through it easier to communicate color over a distance. The
drawings as well as photographs. color from the cervical third to the middle third of
the tooth has one code, and that from the middle
third to the incisal third of the tooth has another
Photographic considerations
code (Figs 1-165a and 1-16sb). The laboratory can
Photographic documentation can be shared between i nterpret the coded color information provided by
the dental ofice and laboratory, providing that the the prosthodontist for numerous ceramic cores to
same (or similar) photographic system is used. develop a dynamic stratification solution (Fig 1-166).
Some photographs should be prepared in the labo· To attain reliable color identification:
ratory so that the dental technician can accurately
record the dynamic features of color, which are 1. Select the guide samples that most closely match
essential to the stratification process and depend on the available colors (eg, Vita, lvoclar). Position
personal visual perception. At present, certain visu· them on the same plane as the reference teeth,
al details still cannot be communicated precisely with the reference dentition in full view, and pho·
FIG 1-163
through photography because of the nuances of tograph the image. ..
fig 1-162 Examples of natural dentitions can be an excellent way of communicating esthetics to the patient. Visual examples
improve the efficacy of the communication. above all from the psychological aspect. and help the clinician to obtain patient
consent and acceptance of the esthetic concepts.
fig 1-163 Esthetic parameters are established by analyzing the examples of the wax models with the patient and comparing
them to the diagnostic wax up of the case. Cooperation and direct communication must exist between the dental technician and
the pat1ent.
ig 1-14 Technician showin g cases previously treated by the prosthetic team and explaining the esthetic potential of the den
tition and a possible restorative treatment.
FIG 1-164
8
CHAPTER 1
A3
• 2. Change the light source to observe the color be of the elements to be reconstructed in the subse
havior of the dental cores; record all information quent stratification process.
corresponding to each ceramic core. The follow The dental technician must imagine the final re
ing light sources should be used:
• Natural light, which highlights the characteris
sult that will be obtained once the baking is com
pleted and the cores have been selected. This requires
A2
tics of cores that have a high refractive index, an in-depth knowledge of the effects of overlapping - --
since the light is highly luminous. However, single ceramic cores as well as the ability to find the
daylight has the lowest lighting value and is right position during the stratification procedure.
FIG 1-165a
inconstant, changing with the time of day and The esthetic effects are derived from the slight inter
the season. mingling of the moist cores as they contact each
• Artificial lighting that burns at s . s oo K, which other, creating shades of color useful for achieving
provides the most constant value as a neutral the natural look of the stratification procedure. Some
light source. The authors recommend turning on times it is extremely difficult to find the ideal posi
the lighting s minutes before use for optimal tion to achieve a satisfactory result. Unfortunately,
eficiency, as well as tracking the hours of the results may be judged a success or failure only
usage because artificial lights tend to deterio after baking has been completed.
rate with use. Standard color samples (eg,Vita, lvoclar) are used
3 . Use two flashes, with one mounted on each in identifying the tooth color without the cervical
side of the camera, to obtain the most precise collar. These samples are later compared with the
photographs. The authors recommend avoiding customized colors of the ceramic system used in the
the use of ring flashes because they reflect the laboratory. The selected reference cores are copied
light excessively and flatten the image. in an individual stratification scheme.
When the color of adjacent natural dentition is
copied, a piece of black cardboard is placed behind
Un dersta n d i n g color
the teeth to absorb the light that filters through the FIG 1-165b
Color must be understood and interpreted; that is, enamel, highlighting the characterizations of the
the ceramist must identify the overlapping of select teeth, in particular the dentin. ..
ed cores in order to conceive the color and the value
Fig 1-165a Separate color matching codes for the gingival and incisal areas of the tooth. These codes help communicate color
parameters over a distance for restorative treatment leg. two central incisors) or redefinition treatment leg. four or six ante
rior teeth). The clinician can easily communicate color information using this system. The ceramist will break down and
interpret these codes into numerous ceramic cores necessary to reproduce the effects.
ig 1-165b Standard color samples (Vital used by dentists to facilitate color matching.
ig 1-166 Stratification scheme created by the dental technician after seeing the patient in person. This solution can also be
obtained by deciphering the coded information communicated by the clinician and dividing the color cores directly from the
standard collection of samples. I n the latter scenario it is also possible to use a number of ceramic cores. varying from 8 to
15. to implement the stratification. even though the information that is provided only describes two colors leg. AJ. C2). j
s 21 � {2 !
2.
� -
FIG 1-166
CHAPTER 1
A3
• 2. Change the light source to observe the color be of the elements to be reconstructed in the subse
havior of the dental cores; record all information quent stratification process.
corresponding to each ceramic core. The follow The dental technician must imagine the final re
ing light sources should be used:
• Natural light, which highlights the characteris
sult that will be obtained once the baking is com
pleted and the cores have been selected. This requires
A2
tics of cores that have a high refractive index, an in-depth knowledge of the effects of overlapping - --
since the light is highly luminous. However, single ceramic cores as well as the ability to find the
daylight has the lowest lighting value and is right position during the stratification procedure.
FIG 1-165a
inconstant, changing with the time of day and The esthetic effects are derived from the slight inter
the season. mingling of the moist cores as they contact each
• Artificial lighting that burns at s . s oo K, which other, creating shades of color useful for achieving
provides the most constant value as a neutral the natural look of the stratification procedure. Some
light source. The authors recommend turning on times it is extremely difficult to find the ideal posi
the lighting s minutes before use for optimal tion to achieve a satisfactory result. Unfortunately,
eficiency, as well as tracking the hours of the results may be judged a success or failure only
usage because artificial lights tend to deterio after baking has been completed.
rate with use. Standard color samples (eg,Vita, lvoclar) are used
3 . Use two flashes, with one mounted on each in identifying the tooth color without the cervical
side of the camera, to obtain the most precise collar. These samples are later compared with the
photographs. The authors recommend avoiding customized colors of the ceramic system used in the
the use of ring flashes because they reflect the laboratory. The selected reference cores are copied
light excessively and flatten the image. in an individual stratification scheme.
When the color of adjacent natural dentition is
copied, a piece of black cardboard is placed behind
Un dersta n d i n g color
the teeth to absorb the light that filters through the FIG 1-165b
Color must be understood and interpreted; that is, enamel, highlighting the characterizations of the
the ceramist must identify the overlapping of select teeth, in particular the dentin. ..
ed cores in order to conceive the color and the value
Fig 1-165a Separate color matching codes for the gingival and incisal areas of the tooth. These codes help communicate color
parameters over a distance for restorative treatment leg. two central incisors) or redefinition treatment leg. four or six ante
rior teeth). The clinician can easily communicate color information using this system. The ceramist will break down and
interpret these codes into numerous ceramic cores necessary to reproduce the effects.
ig 1-165b Standard color samples (Vital used by dentists to facilitate color matching.
ig 1-166 Stratification scheme created by the dental technician after seeing the patient in person. This solution can also be
obtained by deciphering the coded information communicated by the clinician and dividing the color cores directly from the
standard collection of samples. I n the latter scenario it is also possible to use a number of ceramic cores. varying from 8 to
15. to implement the stratification. even though the information that is provided only describes two colors leg. AJ. C2). j
s 21 � {2 !
2.
� -
FIG 1-166
CHAPT[R 1
Managmg The Treatment Plan Wtth The Prosthetic Team
. The protrusive position is the best for displaying For color matching. the technician must accurate· 10. Siegel SC. Driscoll CF. Feldman 5. Tooth stabilization 20. Mirfazaelian A. Fabricating a fit checker. ) Prosthet Dent
and splinting before and a�er periodontal therapy with 2000;8):)76.

the luminous value of the incisal edge of the maXIlla / ly int rpret the composition of the tooth's cores.
fixed panial dentures. Dent Clin Nonh Am 1999;43: 21. Pohjola RM. Fit checker for all ceramic restorations. Oper
anterior te th compared with the mandibular teeth. Since dentin and enamel have ve/ diff rent refrac·
45 76. Dent 2004;29:346.
The technician must va/ the point of observation tion indices and degrees of opacity. they must be
11. Malament KA. Periodontics and prosthodontiCS: Goals, 22. Magne P, Belser U. Bonded Porcelain Restorations in
by altering the viewing axis; this changes the renee· assessed independently.
objectrves. and clinical reality. I Prosthet Dent 1992:67: the Anterior Dentition: A Biomimetic Approach. Chicago:
tion of light on the tooth surface and records the lin· Whenever the expression or the smile needs to
259 ·26). Quintessence. 2002:179-234.
gual characteristics, which are integral to the color· be changed. which is frequently the case, a photo·
12. Morr . Understanding the esthetic evaluation for sue· 23. Magne M. Romeo G. lntereS d'une relation directe entre
matching process. Using a mirror, the technician graph or the patient's face and upper body will help
cess. I Calif Dent Assoc 2004;J2:15J-16o. le prothesiste dentaire et le patient. Reatites Cliniques
should also take a series of slides for visual support the dental technician remember the personality or 2001;12:277-290.
13. Wolfe GN, van der Weijden FA, Spanauf A), de Quincey
when the palatal aspect is stratified. The lingual sur· the patient. GN. Lengthening clinical crowns: A solution for specific 24. agne P, agne M. Belser U. Ceramic laminate veneers:
face is no less important than the buccal surface; Knowledge or the visual characteristics of ceram· periodontal, restorative, and esthetic problems. Quintes Continuous evolution of indications. I Esthet Dent 1997;
the cores that will be used must be copied in an ics is crucial for simulating the effects of natural sence tnt 1994:25:81-88. 9:197-207.
individual stratification scheme in the same way as teeth with artificial cores. The technician needs to 14. Kokich VG. Esthetics: The orthodontic-periodontic restor· 25. Magne P, Douglas WH. Additive contour of porcelain
those selected for the buccal aspect. have met the patient to achieve the best results. ative connection. Semin Orthod 1996:2:21-]0. veneers: A key element in enamel presevation, adhe·
A marked overjet is a bad position for the maxil· Although it may be an excellent qualitative image, 15. Goldstein CE. Catena . Predictable translucency and sion, and esthetics for aging dentition. I Adhes Dent
lal'/ anterior teeth; photographing the profile is ve/ a photograph cannot provide the technician with a aesthetic success with pressed ceramics. Pract Proced 1999:1:8192.
Aesthet Dent 2001:13:365-367. 26. agne P, Magne M. Belser U. The diagnostic template:
useful for quantifying the extent of the problem and nuanced understanding of the numerous light effects
•
16. Belser UC, agne P, agne M. Ceramic laminate veneers: A key element to the comprehensive aesthetic treatment
the dentolabial and maxillomandibular relationships. that take place in the oral cavity.
Continuous evolution of indications. J Esthet Dent 1997: concept. lnt J PeriodontiCS Restorative Dent 1996;16:
9:197-207. 561-569.
17. Blatz MB. Long·term clinical success of atl·ceramic pos· 27. Levrnson NA. sychologic acets of esthetic dental health
terior restorations. Quintessence lnt 2002;)):41S-426. care: A developmental perspective. J Prosthet Dent 1990;
18. Piwowarczyk A, Oul P. Buchler A. Lauer HC, Hofmann A. 64:486-491.
In vitro study on the dimensional accuracy of selected 28. Romeo G. Contomo additivo delle veneers adesive per
materials for monophase elastic impression making. lnt preservare lo smalto e l'estetica. II Nuovo Laboratorio
REFERENCES 5· Akerly WB. Recording jaw relationships in edentulous
J Prosthodont 2002;15:168-174· Odontotecnico 2002;4:37-48.
patients. Dent Clin Nonh Am 1996:40:53-70.
19. White SN. Sorensen )A, Kang SK. Improved marginal
1. Hildeboll CF, Vannler MW, Shrout MK, et at. Periodontal 6. Levine )B. Esthetic diagnosis. Curr Opin Cosmet Dent
seating of cast restorations uslng a silicone disclosing
disease morbidity quanuncation. II. Validation of alveo· 1995:2:9-17.
medium. lnt J Prosthodont 1991;4:323-326.
tar bone loss measurements and vertital defect diagno 7. Garcia LT. Bohnenkamp OM. The use of diagnostic wax·
sis from digital bite·w1ng images. J Periodontal 1990:61: ups In treatment planning. Compend Conlin Educ Dent
623632. 200);24:21D-2 14.
2. Kantor ML, Slome BA. Efficacy of panoramic radlogra· 8. Terry OA. McGuire M. The perio·aesthetlc· restorative
phy In dental diagnosis and treatment planning. I Dent approach for anterior reconstruction. Part 1: Evaluation
Rs 1989:B:81-812. and periodontal surgery. Pract Proced Aesthet Dent
3. lohnson A, Winstanley RB. Recording sagiual condylar 2002;14:283 ·291.
angles using a mand1bular facebow. Oral Rehabil 1997: 9· Terry OA, McGuire M. The perio·aesthetlc·restorative
24 '0'•8. approach for anterior reconstruction. Part II: Restorative
4. Bowley )F, Michaels GC, La1 TW, lin PP. Reliability of a treatment. Pract Proced Aesthet Dent 2002;14:363-369.
facebow transfer procedure. I Prosthrt Dent 1992:67:

491 498.
CHAPT[R 1
Managmg The Treatment Plan Wtth The Prosthetic Team
. The protrusive position is the best for displaying For color matching. the technician must accurate· 10. Siegel SC. Driscoll CF. Feldman 5. Tooth stabilization 20. Mirfazaelian A. Fabricating a fit checker. ) Prosthet Dent
and splinting before and a�er periodontal therapy with 2000;8):)76.

the luminous value of the incisal edge of the maXIlla / ly int rpret the composition of the tooth's cores.
fixed panial dentures. Dent Clin Nonh Am 1999;43: 21. Pohjola RM. Fit checker for all ceramic restorations. Oper
anterior te th compared with the mandibular teeth. Since dentin and enamel have ve/ diff rent refrac·
45 76. Dent 2004;29:346.
The technician must va/ the point of observation tion indices and degrees of opacity. they must be
11. Malament KA. Periodontics and prosthodontiCS: Goals, 22. Magne P, Belser U. Bonded Porcelain Restorations in
by altering the viewing axis; this changes the renee· assessed independently.
objectrves. and clinical reality. I Prosthet Dent 1992:67: the Anterior Dentition: A Biomimetic Approach. Chicago:
tion of light on the tooth surface and records the lin· Whenever the expression or the smile needs to
259 ·26). Quintessence. 2002:179-234.
gual characteristics, which are integral to the color· be changed. which is frequently the case, a photo·
12. Morr . Understanding the esthetic evaluation for sue· 23. Magne M. Romeo G. lntereS d'une relation directe entre
matching process. Using a mirror, the technician graph or the patient's face and upper body will help
cess. I Calif Dent Assoc 2004;J2:15J-16o. le prothesiste dentaire et le patient. Reatites Cliniques
should also take a series of slides for visual support the dental technician remember the personality or 2001;12:277-290.
13. Wolfe GN, van der Weijden FA, Spanauf A), de Quincey
when the palatal aspect is stratified. The lingual sur· the patient. GN. Lengthening clinical crowns: A solution for specific 24. agne P, agne M. Belser U. Ceramic laminate veneers:
face is no less important than the buccal surface; Knowledge or the visual characteristics of ceram· periodontal, restorative, and esthetic problems. Quintes Continuous evolution of indications. I Esthet Dent 1997;
the cores that will be used must be copied in an ics is crucial for simulating the effects of natural sence tnt 1994:25:81-88. 9:197-207.
individual stratification scheme in the same way as teeth with artificial cores. The technician needs to 14. Kokich VG. Esthetics: The orthodontic-periodontic restor· 25. Magne P, Douglas WH. Additive contour of porcelain
those selected for the buccal aspect. have met the patient to achieve the best results. ative connection. Semin Orthod 1996:2:21-]0. veneers: A key element in enamel presevation, adhe·
A marked overjet is a bad position for the maxil· Although it may be an excellent qualitative image, 15. Goldstein CE. Catena . Predictable translucency and sion, and esthetics for aging dentition. I Adhes Dent
lal'/ anterior teeth; photographing the profile is ve/ a photograph cannot provide the technician with a aesthetic success with pressed ceramics. Pract Proced 1999:1:8192.
Aesthet Dent 2001:13:365-367. 26. agne P, Magne M. Belser U. The diagnostic template:
useful for quantifying the extent of the problem and nuanced understanding of the numerous light effects
•
16. Belser UC, agne P, agne M. Ceramic laminate veneers: A key element to the comprehensive aesthetic treatment
the dentolabial and maxillomandibular relationships. that take place in the oral cavity.
Continuous evolution of indications. J Esthet Dent 1997: concept. lnt J PeriodontiCS Restorative Dent 1996;16:
9:197-207. 561-569.
17. Blatz MB. Long·term clinical success of atl·ceramic pos· 27. Levrnson NA. sychologic acets of esthetic dental health
terior restorations. Quintessence lnt 2002;)):41S-426. care: A developmental perspective. J Prosthet Dent 1990;
18. Piwowarczyk A, Oul P. Buchler A. Lauer HC, Hofmann A. 64:486-491.
In vitro study on the dimensional accuracy of selected 28. Romeo G. Contomo additivo delle veneers adesive per
materials for monophase elastic impression making. lnt preservare lo smalto e l'estetica. II Nuovo Laboratorio
REFERENCES 5· Akerly WB. Recording jaw relationships in edentulous
J Prosthodont 2002;15:168-174· Odontotecnico 2002;4:37-48.
patients. Dent Clin Nonh Am 1996:40:53-70.
19. White SN. Sorensen )A, Kang SK. Improved marginal
1. Hildeboll CF, Vannler MW, Shrout MK, et at. Periodontal 6. Levine )B. Esthetic diagnosis. Curr Opin Cosmet Dent
seating of cast restorations uslng a silicone disclosing
disease morbidity quanuncation. II. Validation of alveo· 1995:2:9-17.
medium. lnt J Prosthodont 1991;4:323-326.
tar bone loss measurements and vertital defect diagno 7. Garcia LT. Bohnenkamp OM. The use of diagnostic wax·
sis from digital bite·w1ng images. J Periodontal 1990:61: ups In treatment planning. Compend Conlin Educ Dent
623632. 200);24:21D-2 14.
2. Kantor ML, Slome BA. Efficacy of panoramic radlogra· 8. Terry OA. McGuire M. The perio·aesthetlc· restorative
phy In dental diagnosis and treatment planning. I Dent approach for anterior reconstruction. Part 1: Evaluation
Rs 1989:B:81-812. and periodontal surgery. Pract Proced Aesthet Dent
3. lohnson A, Winstanley RB. Recording sagiual condylar 2002;14:283 ·291.
angles using a mand1bular facebow. Oral Rehabil 1997: 9· Terry OA, McGuire M. The perio·aesthetlc·restorative
24 '0'•8. approach for anterior reconstruction. Part II: Restorative
4. Bowley )F, Michaels GC, La1 TW, lin PP. Reliability of a treatment. Pract Proced Aesthet Dent 2002;14:363-369.
facebow transfer procedure. I Prosthrt Dent 1992:67:

491 498.
C H A P T E R 2
MAGN I F I C AT I O N S Y S TE M S
U S E D I N D E N T I S TR Y
FIG 2-1
T
he two types of magnification instruments but this was a monocular instrument with only one
generally used in dentistry are operating micro enlargement (10x). The experience gave him the idea
scopes and surgical loupes (Figs 2-1 to 2-3). of stereoscopic vision. In 1953, Zeiss presented the
Microscope use has become increasingly popular first stereomicroscope, OPMI 1, which featured coax
among both clinicians and technicians in prostho ial illumination and the ability to vary the working
dontics. restorative dentistry, endodontics, and peri distance.
odontics. •-3 In dentisty, the stereomicroscope was first used
The first specialized magnification systems were by dental technicians for fixed prosthodontics. Since
made in the early twentieth century in )ena, Ger the early 1980s, it has been routinely used in the
many, by an American zoologist named Greenough laboratory to improve the view of preparation mar
and a German technician named Abbe, who worked gins and in the crafting of a precise final prosthesis.
at Zeiss. Their idea was to create a binocular instru Because of the attention to detail required in clini
FIG 2-2
ment that would produce three-dimensional images. cal practice and in the laboratoy, the use of magni
In the early 1920s, a Germany surgeon named Holm fication systems in daily practice continues to
gren irst used an optical microscope i n microsurgery, grow.4-S ..
Fig 2-1 Prismalic surgical loupes with a Zeiss headband used in a lwo-person operalion. The help of a skilled assistanl is
essential for coordinaling the clinicians use of the magnification syslem. so lhal the clinician does nol need to constanlly
pick up and pul down instruments. The reduced visual field is another challenge lhat requires an assislanl who is familiar
with the practical aspects of working al high magnificalions. Fig 2-2 Zeiss OPMI ORL slereomicroscope. equipped wilh an ana
logue slill camera (Contax 1 67MT) and JVC 3CCO ( charge-coupled device! video camera. as well as a coaxial flash for high
magnification photographs. This model has recenlly been superseded by more advanced units. bul it is of great use for lak
ing photographs and working at very high magnificalions ( 1 6 X to 24 X I . The newer models no longer fealure a coaxial flash.
Fig 2-3 Technical laboralory procedures are greally improved by the use microscope. but laboratories must consider the
greater expense of these systems.
A6 2-3
C H A P T E R 2
MAGN I F I C AT I O N S Y S TE M S
U S E D I N D E N T I S TR Y
FIG 2-1
T
he two types of magnification instruments but this was a monocular instrument with only one
generally used in dentistry are operating micro enlargement (10x). The experience gave him the idea
scopes and surgical loupes (Figs 2-1 to 2-3). of stereoscopic vision. In 1953, Zeiss presented the
Microscope use has become increasingly popular first stereomicroscope, OPMI 1, which featured coax
among both clinicians and technicians in prostho ial illumination and the ability to vary the working
dontics. restorative dentistry, endodontics, and peri distance.
odontics. •-3 In dentisty, the stereomicroscope was first used
The first specialized magnification systems were by dental technicians for fixed prosthodontics. Since
made in the early twentieth century in )ena, Ger the early 1980s, it has been routinely used in the
many, by an American zoologist named Greenough laboratory to improve the view of preparation mar
and a German technician named Abbe, who worked gins and in the crafting of a precise final prosthesis.
at Zeiss. Their idea was to create a binocular instru Because of the attention to detail required in clini
FIG 2-2
ment that would produce three-dimensional images. cal practice and in the laboratoy, the use of magni
In the early 1920s, a Germany surgeon named Holm fication systems in daily practice continues to
gren irst used an optical microscope i n microsurgery, grow.4-S ..
Fig 2-1 Prismalic surgical loupes with a Zeiss headband used in a lwo-person operalion. The help of a skilled assistanl is
essential for coordinaling the clinicians use of the magnification syslem. so lhal the clinician does nol need to constanlly
pick up and pul down instruments. The reduced visual field is another challenge lhat requires an assislanl who is familiar
with the practical aspects of working al high magnificalions. Fig 2-2 Zeiss OPMI ORL slereomicroscope. equipped wilh an ana
logue slill camera (Contax 1 67MT) and JVC 3CCO ( charge-coupled device! video camera. as well as a coaxial flash for high
magnification photographs. This model has recenlly been superseded by more advanced units. bul it is of great use for lak
ing photographs and working at very high magnificalions ( 1 6 X to 24 X I . The newer models no longer fealure a coaxial flash.
Fig 2-3 Technical laboralory procedures are greally improved by the use microscope. but laboratories must consider the
greater expense of these systems.
A6 2-3
CHAPTER 2
Magnification Systems Used in Dentistry
. For those contemplating the purchase of a stereo- Surgical lou pes . operating field. The Zeiss system, for example, heavy or uncomfortable. The latter system can be
microscope for clinical or laboratoy work, it is allows a focal distance of 190 mm (Sx) to sao mm fitted with supports directly on the frame and is
important to consider the overall advantages and Galilean system (3.2X) from the operating field (Figs 2-6 to 2-9). The equipped with a threaded mount in the lens area
disadvantages of their operation and management. There is often confusion about the differences be operator must maintain a focal distance between into which protective lenses can be screwed; this
tween prismatic and Galilean systems. The Galilean 300 and 450 mm to assume a posture that is not system is usually preferred by clinicians with impaired
Advantages include: system is composed of a simple eyepiece and damaging to the spinal column. and this position vision. Because these accessory lenses are available
• Better perception of details during all operative another lens without prisms (Fig 2-4). The object in can be obtained only when using the stereomicro· in various gradations, it is possible to adjust the
stages the middle of the visual field remains i n focus, while scope (Fig 2-10).' magnifying apparatus for use without glasses.
• Means of quality control and analysis those on the periphery are distorted. This is a func In the authors' experience, it is a common mis A fiber-optic system connected to a power source
• Proper posture tion of the focal distance and the distance between take for new users to focus on a specific object can also be clipped onto the headband to illuminate
• Ample opportunity for documentation the two lenses. Because of the limited focal area, immediately upon donning the headband. This caus the visual field. It is not compatible with the eye
Galilean systems are professionally fitted for one es disturbances in the user's dioptric functional bal glass-type support. From a clinical perspective, illu·
Disadvantages include: individual. The optician custom sizes the interpupil ance and binocular vision. mination is certainly an advantage, but the addi
• Cumbersomeness and difficulty getting close lary distance, thus preventing the instrument from To avoid these problems, a simple procedure is tional weight of the fiber-optic cable on the head
• Steep learning curve being used by more than one operator. For technical recommended for centering and adapting prismatic band and the constancy of the bright illumination
• Need for skilled assistants reasons, it is not advisable to use a Galilean instru systems to the interpupillary distance. (As noted eventually cause visual and muscular fatigue, mak
• Special operating protocols ment with a magniying power greater than 2.8 X , as earlier, Galilean systems must be adjusted by an ing the accessory impractical in the authors' view.
• High cost will be explained i n the section on Physiologic optician.) First, place the prismatic system's head Fiber optics will be more practical when the weight
Effects and Instrument Maintenance. band firmly around the head without tightening the of the apparatus is reduced.
screws and position the eyepieces 1 em from the eye The headband can also support the attachment
TYPES OF M AG N I YI N G Prisaic system on a horizontal plane. The screw can now be tight of a prismatic telecamera video camera (eg, Telespee,
I N STR U M ENTS The prismatic system has binocular magniying units ened. Next, set the interpupillary distance by adjust 4T Devices). The video telecamera can be connected
consisting of an eyepiece and another lens with a ing the two eyepieces as one would on a telescope, directly to the optical instrument and permits real
A distinction is made between magniying instruments series of intermediate "roof-type" prisms that pro while directing the gaze toward a plain white sur time recording of all that the operator sees. A con
suppoted by the operator (ie, surgical loupes) and duce a clear image in the periphery (Fig 2-5). face. The interpupillary distance is set correctly verter changes the image from a round to a rectan
those that are freestanding or otherwise supported. Prismatic systems can be adjusted by the user. This when the white area in each eyepiece is free of gular viewing ield. This accessory is paticularly
The various types of magniying instruments are system permits magnifications greater than 2.8X shadows or fuzzy halos. Only then should all the useful in teaching and in the recording of images
classified as follows: because it has focal distances of diferent measures screws be tightened definitively. The instrument is (ig 2-ll).
that allow continuous use without visual fatigue. now ready to be used.
• Galilean surgical loupes worn by the operator The magniication ranges from J.2X to 8X and Using surgical lupes
• Prismatic surgical loupes worn by the operator has variable focal distances to match the operator's Accessories for surgical loupes Clinicians and technicians require instruction and
• Operating stereomicroscopes with stand habits and biometric data.6 The ideal range of The headband accessory is a kind of helmet de training on the proper use of both Galilean and pris
• Laboratory stereomicroscopes, countertop model enlargement, i n clinical and practical terms, is from signed to support the optical apparatus suspended matic instruments. There is a learning cuve associ
or with stand 4X to sx because this range allows the operator to in front of the eyes. An eyeglass-type support is also ated with the use of instruments that requires time
• Optical microscopes maintain a proper degree of focal distance from the . available for operators who find the headband too and practice by new users. Based on 20 years of .
" 17
CHAPTER 2
. For those contemplating the purchase of a stereo- Surgical lou pes . operating field. The Zeiss system, for example, heavy or uncomfortable. The latter system can be
microscope for clinical or laboratoy work, it is allows a focal distance of 190 mm (Sx) to sao mm fitted with supports directly on the frame and is
important to consider the overall advantages and Galilean system (3.2X) from the operating field (Figs 2-6 to 2-9). The equipped with a threaded mount in the lens area
disadvantages of their operation and management. There is often confusion about the differences be operator must maintain a focal distance between into which protective lenses can be screwed; this
tween prismatic and Galilean systems. The Galilean 300 and 450 mm to assume a posture that is not system is usually preferred by clinicians with impaired
Advantages include: system is composed of a simple eyepiece and damaging to the spinal column. and this position vision. Because these accessory lenses are available
• Better perception of details during all operative another lens without prisms (Fig 2-4). The object in can be obtained only when using the stereomicro· in various gradations, it is possible to adjust the
stages the middle of the visual field remains i n focus, while scope (Fig 2-10).' magnifying apparatus for use without glasses.
• Means of quality control and analysis those on the periphery are distorted. This is a func In the authors' experience, it is a common mis A fiber-optic system connected to a power source
• Proper posture tion of the focal distance and the distance between take for new users to focus on a specific object can also be clipped onto the headband to illuminate
• Ample opportunity for documentation the two lenses. Because of the limited focal area, immediately upon donning the headband. This caus the visual field. It is not compatible with the eye
Galilean systems are professionally fitted for one es disturbances in the user's dioptric functional bal glass-type support. From a clinical perspective, illu·
Disadvantages include: individual. The optician custom sizes the interpupil ance and binocular vision. mination is certainly an advantage, but the addi
• Cumbersomeness and difficulty getting close lary distance, thus preventing the instrument from To avoid these problems, a simple procedure is tional weight of the fiber-optic cable on the head
• Steep learning curve being used by more than one operator. For technical recommended for centering and adapting prismatic band and the constancy of the bright illumination
• Need for skilled assistants reasons, it is not advisable to use a Galilean instru systems to the interpupillary distance. (As noted eventually cause visual and muscular fatigue, mak
• Special operating protocols ment with a magniying power greater than 2.8 X , as earlier, Galilean systems must be adjusted by an ing the accessory impractical in the authors' view.
• High cost will be explained i n the section on Physiologic optician.) First, place the prismatic system's head Fiber optics will be more practical when the weight
Effects and Instrument Maintenance. band firmly around the head without tightening the of the apparatus is reduced.
screws and position the eyepieces 1 em from the eye The headband can also support the attachment
TYPES OF M AG N I YI N G Prisaic system on a horizontal plane. The screw can now be tight of a prismatic telecamera video camera (eg, Telespee,
I N STR U M ENTS The prismatic system has binocular magniying units ened. Next, set the interpupillary distance by adjust 4T Devices). The video telecamera can be connected
consisting of an eyepiece and another lens with a ing the two eyepieces as one would on a telescope, directly to the optical instrument and permits real
A distinction is made between magniying instruments series of intermediate "roof-type" prisms that pro while directing the gaze toward a plain white sur time recording of all that the operator sees. A con
suppoted by the operator (ie, surgical loupes) and duce a clear image in the periphery (Fig 2-5). face. The interpupillary distance is set correctly verter changes the image from a round to a rectan
those that are freestanding or otherwise supported. Prismatic systems can be adjusted by the user. This when the white area in each eyepiece is free of gular viewing ield. This accessory is paticularly
The various types of magniying instruments are system permits magnifications greater than 2.8X shadows or fuzzy halos. Only then should all the useful in teaching and in the recording of images
classified as follows: because it has focal distances of diferent measures screws be tightened definitively. The instrument is (ig 2-ll).
that allow continuous use without visual fatigue. now ready to be used.
• Galilean surgical loupes worn by the operator The magniication ranges from J.2X to 8X and Using surgical lupes
• Prismatic surgical loupes worn by the operator has variable focal distances to match the operator's Accessories for surgical loupes Clinicians and technicians require instruction and
• Operating stereomicroscopes with stand habits and biometric data.6 The ideal range of The headband accessory is a kind of helmet de training on the proper use of both Galilean and pris
• Laboratory stereomicroscopes, countertop model enlargement, i n clinical and practical terms, is from signed to support the optical apparatus suspended matic instruments. There is a learning cuve associ
or with stand 4X to sx because this range allows the operator to in front of the eyes. An eyeglass-type support is also ated with the use of instruments that requires time
• Optical microscopes maintain a proper degree of focal distance from the . available for operators who find the headband too and practice by new users. Based on 20 years of .
" 17
Fig 2-4 Galilean surgical loupes with an eyeglass-type support and fiber-optic light on a fixed mount. An optician must center and adapt the
Galilean system by measuring the operator's interpupillary distance.
Fig 2-5 Prismatic surgical loupes with headband and fixed fiber-optic system. The interpupillary distance can be adjusted by the operator.
Fig 2-6 Operator working without magnification. The clinician is positioned too close to the patient. and the angle between the dorsal section of
the spinal column and the cervical section is accentuated to about 70 degrees.
Figs 2-7 and 2-8 Galilean and prismatic systems both require a focal distance of 300 mm. The operator maintains a more suitable posture than
without magnification. but still tilts the cervical region of the spine to 40 or 45 degrees.
Fig 2-g Prismatic system at 4.3 X magnification with a focal distance of 400 mm. The operator's posture is improved though still not optimal. The
angle formed by the two vertebral tracts is about 30 degrees.
Fig 2-10 When a stereomicroscope is used. the operator's posture has almost no angle between the dorsal and cervical tracts of the vertebral
column. and the operator's forearms can be held parallel to the ground.
Fig 2-11 4T Telespee video camera mounted directly on the headband and prismatic system. The operator is obtaining real-time images of the
situation being analyzed. Accessories such as fiber-optic illumination. spray-guard lenses. and a video camera can facilitate teaching or other
communication objectives.
1
"
Fig 2-4 Galilean surgical loupes with an eyeglass-type support and fiber-optic light on a fixed mount. An optician must center and adapt the
Galilean system by measuring the operator's interpupillary distance.
Fig 2-5 Prismatic surgical loupes with headband and fixed fiber-optic system. The interpupillary distance can be adjusted by the operator.
Fig 2-6 Operator working without magnification. The clinician is positioned too close to the patient. and the angle between the dorsal section of
the spinal column and the cervical section is accentuated to about 70 degrees.
Figs 2-7 and 2-8 Galilean and prismatic systems both require a focal distance of 300 mm. The operator maintains a more suitable posture than
without magnification. but still tilts the cervical region of the spine to 40 or 45 degrees.
Fig 2-g Prismatic system at 4.3 X magnification with a focal distance of 400 mm. The operator's posture is improved though still not optimal. The
angle formed by the two vertebral tracts is about 30 degrees.
Fig 2-10 When a stereomicroscope is used. the operator's posture has almost no angle between the dorsal and cervical tracts of the vertebral
column. and the operator's forearms can be held parallel to the ground.
Fig 2-11 4T Telespee video camera mounted directly on the headband and prismatic system. The operator is obtaining real-time images of the
situation being analyzed. Accessories such as fiber-optic illumination. spray-guard lenses. and a video camera can facilitate teaching or other
communication objectives.
1
"
CHAPTER 2
Magniication Systems Used in Dentistry
C O I N V I E WE D AT 4 X T O S O x M A G N IF I C AT I O N
Figs 2-12to2-11 Enlargements of a Euro illustrate the possibilities magnification instruments offer, 4 X. B x . l O X . 1 6 X . 2 4 X .
a n d SOX. respe ctively. Magnification a t S O x c a n be u s e d only f o r photography. n o t f o r operative purposes.
. experience, the authors recommend initially using rectly, an immediate advantage is the ease with .. Stereom icroscopes plane on which the object being viewed is resting .
these instruments for limited procedures, perhaps which the preparations of the maxillay teeth can be In the Greenough-type system, two identical lenses
beginning with Class 5 restorations where access is accomplished (indirect vision). Because the chances The stereomicroscope is a technologically advanced are positioned at a n 11- to 16-degree incline in rela
easy. Once these are mastered, users can move on of creating undesirable undercuts is greatly reduced, instrument that achieves all of the magnifications tion to a third lens. The axes of this optical system
to marginal finishing of preparations i n the anterior the quality of the preparations improves consider and focal distances used in clinical and laboratory are not perpendicular to the plane of the object
areas before finally applying them in all phases of ably. work (Fig 2-18). The operator can use magniications being viewed. The magniying system is mounted on
preparation. This type of gradual training enables The authors have found that excessive use of ranging from 4X to 25 x while maintaining optimal a stand or base using magnets or friction and can
the operator to adapt to the instrument's different magnifiers is a common problem. Some operators posture and vision (see Fig 2·10).7-9 be attached to the floor, a wall, or the ceiling (Figs
visualization of spatial relationships and its efect on routinely perform all procedures under magnification 2-19 to 2-21). The system is called stereoscopic be
the perception of parallelism in the preparation of out of convenience and a desire to see objects bet Types of stereomicroscopes cause it consists of two lenses centered on the same
several teeth. Another factor to consider is the ter, even when it is not necessary (eg, in objective The two types of stereomicroscopes are the tete object, allowing each of the two eyes to perceive a
reduction or enlargement of the field of vision in examinations of the oral cavity). Magnifying systems scope type (eg, Stemi SV 6 and SV 11, Zeiss) and the diferent image and requiring the construction of a
proportion to the degree of enlargement. For should be used in moderation to prevent the devel Greenough type (Stemi 1000 and 2000, Zeiss). The three-dimensional precept by the visual system. ..
instance, the visual field becomes proportionately opment of visual disturbances such as those de telescope-type system operates on the principle of
smaller at higher magniications (Figs 2-12 to 2-17). scribed in the section on Physiologic Effects and two separate but parallel optic paths, which use the
Ater learning to use these enlargement systems cor- Instrument Maintenance. same primay lens. The axis is perpendicular to the
0 71
CHAPTER 2
C O I N V I E WE D AT 4 X T O S O x M A G N IF I C AT I O N
Figs 2-12to2-11 Enlargements of a Euro illustrate the possibilities magnification instruments offer, 4 X. B x . l O X . 1 6 X . 2 4 X .
a n d SOX. respe ctively. Magnification a t S O x c a n be u s e d only f o r photography. n o t f o r operative purposes.
. experience, the authors recommend initially using rectly, an immediate advantage is the ease with .. Stereom icroscopes plane on which the object being viewed is resting .
these instruments for limited procedures, perhaps which the preparations of the maxillay teeth can be In the Greenough-type system, two identical lenses
beginning with Class 5 restorations where access is accomplished (indirect vision). Because the chances The stereomicroscope is a technologically advanced are positioned at a n 11- to 16-degree incline in rela
easy. Once these are mastered, users can move on of creating undesirable undercuts is greatly reduced, instrument that achieves all of the magnifications tion to a third lens. The axes of this optical system
to marginal finishing of preparations i n the anterior the quality of the preparations improves consider and focal distances used in clinical and laboratory are not perpendicular to the plane of the object
areas before finally applying them in all phases of ably. work (Fig 2-18). The operator can use magniications being viewed. The magniying system is mounted on
preparation. This type of gradual training enables The authors have found that excessive use of ranging from 4X to 25 x while maintaining optimal a stand or base using magnets or friction and can
the operator to adapt to the instrument's different magnifiers is a common problem. Some operators posture and vision (see Fig 2·10).7-9 be attached to the floor, a wall, or the ceiling (Figs
visualization of spatial relationships and its efect on routinely perform all procedures under magnification 2-19 to 2-21). The system is called stereoscopic be
the perception of parallelism in the preparation of out of convenience and a desire to see objects bet Types of stereomicroscopes cause it consists of two lenses centered on the same
several teeth. Another factor to consider is the ter, even when it is not necessary (eg, in objective The two types of stereomicroscopes are the tete object, allowing each of the two eyes to perceive a
reduction or enlargement of the field of vision in examinations of the oral cavity). Magnifying systems scope type (eg, Stemi SV 6 and SV 11, Zeiss) and the diferent image and requiring the construction of a
proportion to the degree of enlargement. For should be used in moderation to prevent the devel Greenough type (Stemi 1000 and 2000, Zeiss). The three-dimensional precept by the visual system. ..
instance, the visual field becomes proportionately opment of visual disturbances such as those de telescope-type system operates on the principle of
smaller at higher magniications (Figs 2-12 to 2-17). scribed in the section on Physiologic Effects and two separate but parallel optic paths, which use the
Ater learning to use these enlargement systems cor- Instrument Maintenance. same primay lens. The axis is perpendicular to the
0 71
CHAPTER 2
.. Advantages of stereoscopic vision Stereoscopic agnification

Stereoscopic vision offers the ability to increase the One of the interesting aspects of the stereomicro
depth of field, an advantage that allows the user to scope is that the operator knows the levels of mag
maintain a suitable working distance for clinical oper nification that can be achieved with a particular
ations.'0 A greater depth of ield is useful in every instrument and can thus view the degree of enlarge
stage of work (tooth preparation, for instance) because ment during every stage of operation. However, the
it permits the viewer to observe the entire length of values shown on the instrument do not reflect the
the preparation even at high magnification (Fig 2-22). focal distance and the eyepiece factor. To determine
The stereomicroscope is also helpful in the clini the true degree of enlargement, the operator must
cal analysis of i mpressions (Fig 2-23). Generally, an apply the following formula:
impression is visually inspected by the clinician
immediately after it is removed from the oral cavity. focal tube length + objective focal lens distance
If approved, the i mpression is sent to a dental labo X eyepiece factor X magnifying value
ratoy, where the master cast is made. Imperfections
are more noticeable on the cast, which is the posi For example, the authors' operating stereomicro
tive inversion of the impression, than on the actual scope has a focal tube length of 170 mm, a focal lens
(negative) impression. Ater the i mpression has been distance of 200 mm, an eyepiece factor of 12, and a
poured, the dental technician often suggests that the magnification range of 8X to 2 5 X . For convenience,
impression be retaken at a subsequent clinical appoint operators can approximate 2.4 as corresponding to
ment. This is inconvenient for the patient, who is 2 5 X magnification and o.8 as corresponding to Bx
once more subjected to a time-consuming and un magnification. Therefore, for maximum magnification:
pleasant procedure, and for the clinician, who loses
time and money in correcting an error. In the authors' 170 + 200 x 12 x 2 - 4 = 24-48 magnification
2-20 2•2 1
opinion, the ability to examine impressions under
powerful magniication before sending it to a dental To determine the minimum degree of magnification:
laboratory is one of the principal reasons for equip
ping a clinician's office with a stereomicroscope. 170 + 200 x 1 2 x o.B = 8.16 magnification
For clinicians who do not wish to use an operat
Rg 2-18 Detail of the optic group and directional command knobs of a Leica MSOO stereomicroscope. The instrument is quite versatile and
ing microscope during clinical procedures, it is pos Accessoy lenses can range from 150 to Boo mm, and
lighl. and it easily moves and refocuses. guided solely by the movement of the forehead and eyes.
sible to purchase freestanding instruments that are some microscopes have eyepiece factors of 10. Rg2-1 g Leica MSOO stereomicroscope with floor-based stand. This unit can be moved to different operating rooms. unlike ceiling- or wall
ideal for checking the quality of impressions. These Lenses of 200 and 250 mm permit optimal and mounted units.
F1g 2-20 Zeiss OPMI PROergo operating stereomicroscope with wall-mounted supporl. It is important to carefully analyze the range of
instruments, which are less expensive than an oper ergonomically sound working distances. To increase
motion of this instrument before mounting the support to avoid difficullies in function.
ating microscope, also permit the clinician to finish magnification, a focal lens distance of 150 mm can F1g 2-21 Zeiss OPMI PROergo stereomicroscope with ceiling mounl. This is the most practical and ergonomic solution for a fixed instrument
provisional prostheses and check the casting of pros be used: because it has the greatest range of motion. However. the stereomicroscope cannot be moved to other operating areas.
theses before fitting them in the patient's mouth

(Figs 2-24 and 2-25). The objective lens and the eye 170 + 150 X 1 2 X 2.4 = 32.64 magnification
piece are the basic components: the irst captures
the image of the object to be enlarged, and the sec· However, this reduces the working distance and ere-
ond, after another magnification, conveys the image ates less comfortable conditions. ..
through two visual systems. one for each eye.
n n
CHAPTER 2
.. Advantages of stereoscopic vision Stereoscopic agnification

Stereoscopic vision offers the ability to increase the One of the interesting aspects of the stereomicro
depth of field, an advantage that allows the user to scope is that the operator knows the levels of mag
maintain a suitable working distance for clinical oper nification that can be achieved with a particular
ations.'0 A greater depth of ield is useful in every instrument and can thus view the degree of enlarge
stage of work (tooth preparation, for instance) because ment during every stage of operation. However, the
it permits the viewer to observe the entire length of values shown on the instrument do not reflect the
the preparation even at high magnification (Fig 2-22). focal distance and the eyepiece factor. To determine
The stereomicroscope is also helpful in the clini the true degree of enlargement, the operator must
cal analysis of i mpressions (Fig 2-23). Generally, an apply the following formula:
impression is visually inspected by the clinician
immediately after it is removed from the oral cavity. focal tube length + objective focal lens distance
If approved, the i mpression is sent to a dental labo X eyepiece factor X magnifying value
ratoy, where the master cast is made. Imperfections
are more noticeable on the cast, which is the posi For example, the authors' operating stereomicro
tive inversion of the impression, than on the actual scope has a focal tube length of 170 mm, a focal lens
(negative) impression. Ater the i mpression has been distance of 200 mm, an eyepiece factor of 12, and a
poured, the dental technician often suggests that the magnification range of 8X to 2 5 X . For convenience,
impression be retaken at a subsequent clinical appoint operators can approximate 2.4 as corresponding to
ment. This is inconvenient for the patient, who is 2 5 X magnification and o.8 as corresponding to Bx
once more subjected to a time-consuming and un magnification. Therefore, for maximum magnification:
pleasant procedure, and for the clinician, who loses
time and money in correcting an error. In the authors' 170 + 200 x 12 x 2 - 4 = 24-48 magnification
2-20 2•2 1
opinion, the ability to examine impressions under
powerful magniication before sending it to a dental To determine the minimum degree of magnification:
laboratory is one of the principal reasons for equip
ping a clinician's office with a stereomicroscope. 170 + 200 x 1 2 x o.B = 8.16 magnification
For clinicians who do not wish to use an operat
Rg 2-18 Detail of the optic group and directional command knobs of a Leica MSOO stereomicroscope. The instrument is quite versatile and
ing microscope during clinical procedures, it is pos Accessoy lenses can range from 150 to Boo mm, and
lighl. and it easily moves and refocuses. guided solely by the movement of the forehead and eyes.
sible to purchase freestanding instruments that are some microscopes have eyepiece factors of 10. Rg2-1 g Leica MSOO stereomicroscope with floor-based stand. This unit can be moved to different operating rooms. unlike ceiling- or wall
ideal for checking the quality of impressions. These Lenses of 200 and 250 mm permit optimal and mounted units.
F1g 2-20 Zeiss OPMI PROergo operating stereomicroscope with wall-mounted supporl. It is important to carefully analyze the range of
instruments, which are less expensive than an oper ergonomically sound working distances. To increase
motion of this instrument before mounting the support to avoid difficullies in function.
ating microscope, also permit the clinician to finish magnification, a focal lens distance of 150 mm can F1g 2-21 Zeiss OPMI PROergo stereomicroscope with ceiling mounl. This is the most practical and ergonomic solution for a fixed instrument
provisional prostheses and check the casting of pros be used: because it has the greatest range of motion. However. the stereomicroscope cannot be moved to other operating areas.
theses before fitting them in the patient's mouth

(Figs 2-24 and 2-25). The objective lens and the eye 170 + 150 X 1 2 X 2.4 = 32.64 magnification
piece are the basic components: the irst captures
the image of the object to be enlarged, and the sec· However, this reduces the working distance and ere-
ond, after another magnification, conveys the image ates less comfortable conditions. ..
through two visual systems. one for each eye.
n n
CHAPTER 2
.. Accessories for operatin g microscopes For all of these periodontal procedures. the operat
Manufacturers now produce instruments with vari ing stereomicroscope is associated with superior
able focal distances as well as inserts and other clinical healing when compared with traditional tech·
accessories (Fig 2-26), all intended to improve their niques; such differences are well documented in the
practical value. permit video recording and still pho literature -"->S
tography, and facilitate their use i n a limited space
or under conditions where access is dificult." Using CoSerBtve rstomtve tratment
the stereomicroscope i n indirect vision. it is now • Cavity preparation
possible to access and view all areas of the oral cav Finishing and polishing of various restorative
ity and all dental surfaces. The image is reflected in materials
a rhodium-plated operating mirror that has a slight
ly larger diameter to promote the most optimal Prsthodonts
working posture. In the authors' view, there are specific applications
of the operating stereomicroscope in prosthodon
Areas of application tics, and procedures for use with both traditiona\'6
The operating microscope is used by dental special and esthetic'7 prostheses have been described.'a
ists engaged in clinical practice of the various pro
cedures listed below (Figs 2-27 to 2-31). • Primay preparation
• Repositioning of the finish line
oSwgal endodonts • Finishing stage
• Locating root canal openings • Evaluation of the impression
• Reaming root canals • Finishing of the provisional prosthesis
• Removing broken instruments and various types • Evaluation of the framework on the stone master
of canal pins cast
• Obturating false paths • Evaluation of the casting in the patient's mouth
• Esthetic evaluation (texture)
Swgal endodonts • Removal of excess cement
• Apicoectomies
• Retrograde radicular obturation The authors do not use the microscope for routine
separation and shaping during the initial preparation
erodonts because the field is too small and the tooth prepa
• Mucogingival surgey ration is difficult to see in relation to the other teeth Figs 2-22 and 2-23 Magnified analysis of tooth preparation and impression. Depth of field is fully exploited in analyzing the impression: the
operator can check the finish lines as well as the internal portion of the impression. where slratned spots and uneven 1reas should be visible.
• Resective surgery to be prepared, risking serious errors of parallelism Figs 2-24 and 2-25 Finishing of a provisional restoration is easier to complete using a freestanding. countertop microscope. This type of m icro
• Regenerative surgery and undercut. . scope can also be used to evaluate the quality of an impression or the framework coming from the laboratory before try-in.
Fig 2-26 Accessories for a leica stereomicroscope. Clockwise from top left: adapter for simultaneous use of still and video cameras: double
diaphragm. iris-type. for regulating depth of field: video camera TV adapter: and removable. sterilizable control knobs.
74 5
CHAPTER 2
.. Accessories for operatin g microscopes For all of these periodontal procedures. the operat
Manufacturers now produce instruments with vari ing stereomicroscope is associated with superior
able focal distances as well as inserts and other clinical healing when compared with traditional tech·
accessories (Fig 2-26), all intended to improve their niques; such differences are well documented in the
practical value. permit video recording and still pho literature -"->S
tography, and facilitate their use i n a limited space
or under conditions where access is dificult." Using CoSerBtve rstomtve tratment
the stereomicroscope i n indirect vision. it is now • Cavity preparation
possible to access and view all areas of the oral cav Finishing and polishing of various restorative
ity and all dental surfaces. The image is reflected in materials
a rhodium-plated operating mirror that has a slight
ly larger diameter to promote the most optimal Prsthodonts
working posture. In the authors' view, there are specific applications
of the operating stereomicroscope in prosthodon
Areas of application tics, and procedures for use with both traditiona\'6
The operating microscope is used by dental special and esthetic'7 prostheses have been described.'a
ists engaged in clinical practice of the various pro
cedures listed below (Figs 2-27 to 2-31). • Primay preparation
• Repositioning of the finish line
oSwgal endodonts • Finishing stage
• Locating root canal openings • Evaluation of the impression
• Reaming root canals • Finishing of the provisional prosthesis
• Removing broken instruments and various types • Evaluation of the framework on the stone master
of canal pins cast
• Obturating false paths • Evaluation of the casting in the patient's mouth
• Esthetic evaluation (texture)
Swgal endodonts • Removal of excess cement
• Apicoectomies
• Retrograde radicular obturation The authors do not use the microscope for routine
separation and shaping during the initial preparation
erodonts because the field is too small and the tooth prepa
• Mucogingival surgey ration is difficult to see in relation to the other teeth Figs 2-22 and 2-23 Magnified analysis of tooth preparation and impression. Depth of field is fully exploited in analyzing the impression: the
operator can check the finish lines as well as the internal portion of the impression. where slratned spots and uneven 1reas should be visible.
• Resective surgery to be prepared, risking serious errors of parallelism Figs 2-24 and 2-25 Finishing of a provisional restoration is easier to complete using a freestanding. countertop microscope. This type of m icro
• Regenerative surgery and undercut. . scope can also be used to evaluate the quality of an impression or the framework coming from the laboratory before try-in.
Fig 2-26 Accessories for a leica stereomicroscope. Clockwise from top left: adapter for simultaneous use of still and video cameras: double
diaphragm. iris-type. for regulating depth of field: video camera TV adapter: and removable. sterilizable control knobs.
74 5
CHAPTER 2
� Many clinicians use the microscope for all proce- Optical m icroscopes
dures, which is, in the authors' view, counterproduc
tive to an optimal clinical outcome, because a per Several highly developed types of microscopes, such
fed finish line i n two divergent tooth prepa �ations as the optical microscope, also are available for use
results i n distortion of the i mpression. With regard to in dentistry, but they are suitable for research and
dental technology, the microscope is principally used analysis rather than for clinical operations. Unlike
for the following (Figs 2-32 to 2-36): the stereomicroscope, the optical microscope (Fig
2-37) uses only one objective lens that permits mag
• Analysis of the i mpression nifications of t.ooox and greater. The lens is posi
• Marking of the inish line tioned vey close to the object being observed and, A P P l i C AT I O N S 0F T H E STER E O M I C R O S C O P E
• Evaluation of waxup fit because of the high magnification, is impractical for
• Veriication a fter removal of the wax coping clinical work on a patient. Between the objective
• Evaluation of casting fit lens and the eyepiece lenses, the image is duplicat
• Evaluation of soldering ed by a prism system inside the binocular tube, then
• Evaluation of ceramic fit magnified by a series of mi rrors, and finally enlarged
• Polishing of prosthesis margins again by the eyepiece lenses. This complex optical
system is ideal for examining cells and tissues, but
The fact that one rarely sees the stereomicroscope the images it produces are basically flat.'9
used for working with prostheses is presumably due Operating stereomicroscopes and other magniica
to the dificulty of handling the instrument, especial tion instruments are widely used in dentistry, espe
ly because the object must be worked on in circum cially i n modern endodontics 2�23 and endodontic
ference. It is important to learn the proper working microsurgey. 24 Under ideal circumstances, manufac
position to accommodate the movement of the micro turers would develop instruments specifically for
scope in order to keep the object in constant focus. ergonomic application in dentisty. While we wait for
The numerous clinical and laboratory procedures that to happen, manufacturers continue to adapt
involving high-powered magnification have made it a their operating microscopes, which are designed for
widely accepted technical tool. However, to use high neurosurgery and ophthalmologic surgery, by design
powered magnification instruments, one should have ing accessories and systems that address the prob-
a genuine interest in stereomicroscopes. Othewise, \ems unique to the practice of clinical dentistry. .
its use would probably present insurmountable difi

culties.
Fig 2 27 Chamber opening and mouth of four root canals in a maxillary molar as seen through a stereomicroscope. F1g 2-28 Open
apices of a maxillary premolar. extracted for orthodontic treatment. Fig 2-29 Apex of an extracted tooth. Fig 2-30 Restoration
margins magnified for careful analysis. Fig 2-31 Potyether impression at 50 X . showing an even preporation and marks left by
the scalpels during the finishing stage.
76 n
CHAPTER 2
� Many clinicians use the microscope for all proce- Optical m icroscopes
dures, which is, in the authors' view, counterproduc
tive to an optimal clinical outcome, because a per Several highly developed types of microscopes, such
fed finish line i n two divergent tooth prepa �ations as the optical microscope, also are available for use
results i n distortion of the i mpression. With regard to in dentistry, but they are suitable for research and
dental technology, the microscope is principally used analysis rather than for clinical operations. Unlike
for the following (Figs 2-32 to 2-36): the stereomicroscope, the optical microscope (Fig
2-37) uses only one objective lens that permits mag
• Analysis of the i mpression nifications of t.ooox and greater. The lens is posi
• Marking of the inish line tioned vey close to the object being observed and, A P P l i C AT I O N S 0F T H E STER E O M I C R O S C O P E
• Evaluation of waxup fit because of the high magnification, is impractical for
• Veriication a fter removal of the wax coping clinical work on a patient. Between the objective
• Evaluation of casting fit lens and the eyepiece lenses, the image is duplicat
• Evaluation of soldering ed by a prism system inside the binocular tube, then
• Evaluation of ceramic fit magnified by a series of mi rrors, and finally enlarged
• Polishing of prosthesis margins again by the eyepiece lenses. This complex optical
system is ideal for examining cells and tissues, but
The fact that one rarely sees the stereomicroscope the images it produces are basically flat.'9
used for working with prostheses is presumably due Operating stereomicroscopes and other magniica
to the dificulty of handling the instrument, especial tion instruments are widely used in dentistry, espe
ly because the object must be worked on in circum cially i n modern endodontics 2�23 and endodontic
ference. It is important to learn the proper working microsurgey. 24 Under ideal circumstances, manufac
position to accommodate the movement of the micro turers would develop instruments specifically for
scope in order to keep the object in constant focus. ergonomic application in dentisty. While we wait for
The numerous clinical and laboratory procedures that to happen, manufacturers continue to adapt
involving high-powered magnification have made it a their operating microscopes, which are designed for
widely accepted technical tool. However, to use high neurosurgery and ophthalmologic surgery, by design
powered magnification instruments, one should have ing accessories and systems that address the prob-
a genuine interest in stereomicroscopes. Othewise, \ems unique to the practice of clinical dentistry. .
its use would probably present insurmountable difi

culties.
Fig 2 27 Chamber opening and mouth of four root canals in a maxillary molar as seen through a stereomicroscope. F1g 2-28 Open
apices of a maxillary premolar. extracted for orthodontic treatment. Fig 2-29 Apex of an extracted tooth. Fig 2-30 Restoration
margins magnified for careful analysis. Fig 2-31 Potyether impression at 50 X . showing an even preporation and marks left by
the scalpels during the finishing stage.
76 n
CHAPTER 2
2-3 7
Figs 2-32 to 2-36 Stages of laboratory work performed using the stereomicroscope. Fig 2-32 Trimming of the stone cast.
Fig 2-33 Marking the finish tine with a wax marker. Fig 2-34 Application of die spacer. Fig 2-35 Finishing the restoration
margin in wax. Fig 2-36 Mechanical edge finishing of the casting.
Fig 2-37 Optical microscope for analyzing celts and tissues. Very high magnifications are possible. but it cannot be
used in the oral cavity or for prosthetic laboratory work.
11
19
CHAPTER 2
2-3 7
Figs 2-32 to 2-36 Stages of laboratory work performed using the stereomicroscope. Fig 2-32 Trimming of the stone cast.
Fig 2-33 Marking the finish tine with a wax marker. Fig 2-34 Application of die spacer. Fig 2-35 Finishing the restoration
margin in wax. Fig 2-36 Mechanical edge finishing of the casting.
Fig 2-37 Optical microscope for analyzing celts and tissues. Very high magnifications are possible. but it cannot be
used in the oral cavity or for prosthetic laboratory work.
11
19
CHAPTER 2
.. PHYS I O LO G I C E F F ECTS A N D of accommodation, brings the object into focus.

TAB L E 2 -� Compa rson of the ats of a p rs atc sstem and a s tereomcrsope
I N ST R U M ENT M A I NTENANCE Psychoproximal convergence is a reflex mechanism,
present almost from birth, that provides feedback
Features Prismatic system Stereomicroscope
Many clinicians a r e unaware of t h e pathologies on the position of the eyes relative not to where the
associated with the daily use of an enlargement sys object appears to be, but to where it actually is. Optical axis Convergent Parallel
tem. For instance, the operator's normal vision is When using the stereomicroscope, objects may Degree of m a g nification 3.2X to 8X 4 X to s o x
afeded, and the muscles of the upper body are typ sometimes appear out of focus because of this con Type of i l l u m i nation External Coaxial
ically fatigued.'S Daily microscope use in clinical flict caused by the disparity between the actual and Versatility
practice can lead to problems that are either physi perceived distance of the object. To maintain diop· • Type of i m a ge (s) Image on movement Still
ologic or instrumental in origin. tric balance, the observer must make continual
• Size accessibility Portable Stationary
adjustments in accommodation to see distinctly, and
Cost Reasonable High
this can cause eye fatigue. Adjustments i n the focal
Physiologic efects
distance and the interpupillary distance make the
Daily use of an enlargement system can interfere image clear, but the viewer continues to converge
with the operator's binocular vision and/or alter the and accommodate excessively.
operator's dioptric fundional balance. Binocular vision Magnification instruments are now used routinely
problems usually i nvolve a reduction in peripheral in many areas of medicine (eg, pathology, vascular
..Instrument m a i ntenance S U M M ARY
vision, which is responsible for combining two sep surgery, neurosurgery, and ophthalmologic surgery)
arate images into a single three-dimensional binoc· and in technologic sedors such as the pharma Like other tools, magniying instruments sufer from Today's prismatic surgical loupes are more versatile
ular precept. The peripheral areas of the retina are ceutics, aeronautics, and automotive industries. The prolonged wear and use. For example, the instru· and thus more practical than the stereomicroscope
involved i n the union of the two images, while the widespread use of image-enlargement tools in tech ment may become "of center," causing focusing (Table 2-1). When using operating microscopes, pro
paramacular areas maintain the perception of the nological sectors can be considered an indication of irregularities that require the viewer to continuously dudion costs increase the overhead expenses i n
single image.26 Fixation on a single image restricts their safety. converge and accommodate the eyes independently, general, especially during t h e initial training period,
the peripheral field and may lead to a reduced Generally, physicians are sensitive to the problems resulting in an unnatural and irregular precept. After and laboratories using stereomicroscopes must im·
capacity for peripheral vision, causing stress and and pathologies caused by the use of various instru· years of use, oxidation reduces the transparency of pose higher prices as well. Because of the high cost
fatigue as well. ments. Studies conducted in the workplace on the lenses and prisms, resulting in a marked difer of purchasing and maintaining a stereomicroscope
The operator's dioptric functional equilibrium may industrial personnel have found mild visual distur· ence in luminosity between the eyes and reducing or as well as the space it occupies and the diiculty in
be altered when a n objed that the nervous system bances in the capacity for abduction, adduction, enhancing visibility, possibly leading to monocular using it in operations, prismatic systems are much
knows to be only 10 to 15 inches away is adually convergence, and visual fatigue (asthenopia), as well vision. To avoid these problems, it is important to more popular.
perceived as i f it were distant. If it persists for an as temporarily blurred vision.'�2 8 For individuals keep all magniying instruments in optimal condition However, the authors are firmly convinced that in
extended period, this situation creates problems for who spend many hours using these systems, the fol through a routine of daily and periodic maintenance. the long term, the capacity for greater precision
the visual system. Even though the operator knows lowing are crucial to reduce possible disturbances: The lenses should be cleaned with special optical pays of economically, reducing the working time of
an objed is close, the perception of it as distant cloths before and after use. In addition, cleaning phases and the number of costly readjustments and
forces the visual system to maintain the dioptric • Training in the proper use of the instrument with a liquid cleaner such as ethyl alcohol or dena· increasing the longevity of the restoration.'9 I n the
functional balance that is used for looking at distant • Correct use of the instrument tured alcohol is recommended periodically. General right situation and with careful attention to training,
objeds with parallel visual axes. When an object • Suitable ambient illumination maintenance procedures should be performed at the stereomicroscope can become a commonly used
close to the eyes is viewed under normal conditions, • Thorough periodic vision checkups least once a year by skilled personnel, including the instrument in dentistry, providing undeniable advan-
the psychoproximal convergence mechanism comes • Daily and periodic maintenance of the instrument .. control and verification of alignment of the focal tages for clinicians and, above all, their patients. •
into play and, through cooperation with the process planes and oxidation of the optical elements.
It
CHAPTER 2
.. PHYS I O LO G I C E F F ECTS A N D of accommodation, brings the object into focus.

TAB L E 2 -� Compa rson of the ats of a p rs atc sstem and a s tereomcrsope
I N ST R U M ENT M A I NTENANCE Psychoproximal convergence is a reflex mechanism,
present almost from birth, that provides feedback
Features Prismatic system Stereomicroscope
Many clinicians a r e unaware of t h e pathologies on the position of the eyes relative not to where the
associated with the daily use of an enlargement sys object appears to be, but to where it actually is. Optical axis Convergent Parallel
tem. For instance, the operator's normal vision is When using the stereomicroscope, objects may Degree of m a g nification 3.2X to 8X 4 X to s o x
afeded, and the muscles of the upper body are typ sometimes appear out of focus because of this con Type of i l l u m i nation External Coaxial
ically fatigued.'S Daily microscope use in clinical flict caused by the disparity between the actual and Versatility
practice can lead to problems that are either physi perceived distance of the object. To maintain diop· • Type of i m a ge (s) Image on movement Still
ologic or instrumental in origin. tric balance, the observer must make continual
• Size accessibility Portable Stationary
adjustments in accommodation to see distinctly, and
Cost Reasonable High
this can cause eye fatigue. Adjustments i n the focal
Physiologic efects
distance and the interpupillary distance make the
Daily use of an enlargement system can interfere image clear, but the viewer continues to converge
with the operator's binocular vision and/or alter the and accommodate excessively.
operator's dioptric fundional balance. Binocular vision Magnification instruments are now used routinely
problems usually i nvolve a reduction in peripheral in many areas of medicine (eg, pathology, vascular
..Instrument m a i ntenance S U M M ARY
vision, which is responsible for combining two sep surgery, neurosurgery, and ophthalmologic surgery)
arate images into a single three-dimensional binoc· and in technologic sedors such as the pharma Like other tools, magniying instruments sufer from Today's prismatic surgical loupes are more versatile
ular precept. The peripheral areas of the retina are ceutics, aeronautics, and automotive industries. The prolonged wear and use. For example, the instru· and thus more practical than the stereomicroscope
involved i n the union of the two images, while the widespread use of image-enlargement tools in tech ment may become "of center," causing focusing (Table 2-1). When using operating microscopes, pro
paramacular areas maintain the perception of the nological sectors can be considered an indication of irregularities that require the viewer to continuously dudion costs increase the overhead expenses i n
single image.26 Fixation on a single image restricts their safety. converge and accommodate the eyes independently, general, especially during t h e initial training period,
the peripheral field and may lead to a reduced Generally, physicians are sensitive to the problems resulting in an unnatural and irregular precept. After and laboratories using stereomicroscopes must im·
capacity for peripheral vision, causing stress and and pathologies caused by the use of various instru· years of use, oxidation reduces the transparency of pose higher prices as well. Because of the high cost
fatigue as well. ments. Studies conducted in the workplace on the lenses and prisms, resulting in a marked difer of purchasing and maintaining a stereomicroscope
The operator's dioptric functional equilibrium may industrial personnel have found mild visual distur· ence in luminosity between the eyes and reducing or as well as the space it occupies and the diiculty in
be altered when a n objed that the nervous system bances in the capacity for abduction, adduction, enhancing visibility, possibly leading to monocular using it in operations, prismatic systems are much
knows to be only 10 to 15 inches away is adually convergence, and visual fatigue (asthenopia), as well vision. To avoid these problems, it is important to more popular.
perceived as i f it were distant. If it persists for an as temporarily blurred vision.'�2 8 For individuals keep all magniying instruments in optimal condition However, the authors are firmly convinced that in
extended period, this situation creates problems for who spend many hours using these systems, the fol through a routine of daily and periodic maintenance. the long term, the capacity for greater precision
the visual system. Even though the operator knows lowing are crucial to reduce possible disturbances: The lenses should be cleaned with special optical pays of economically, reducing the working time of
an objed is close, the perception of it as distant cloths before and after use. In addition, cleaning phases and the number of costly readjustments and
forces the visual system to maintain the dioptric • Training in the proper use of the instrument with a liquid cleaner such as ethyl alcohol or dena· increasing the longevity of the restoration.'9 I n the
functional balance that is used for looking at distant • Correct use of the instrument tured alcohol is recommended periodically. General right situation and with careful attention to training,
objeds with parallel visual axes. When an object • Suitable ambient illumination maintenance procedures should be performed at the stereomicroscope can become a commonly used
close to the eyes is viewed under normal conditions, • Thorough periodic vision checkups least once a year by skilled personnel, including the instrument in dentistry, providing undeniable advan-
the psychoproximal convergence mechanism comes • Daily and periodic maintenance of the instrument .. control and verification of alignment of the focal tages for clinicians and, above all, their patients. •
into play and, through cooperation with the process planes and oxidation of the optical elements.
It
CHAPTER 2
R E F E R E N CES 10. Erten H, Uctasli MB, Akarslan U, Uzun 0, Baspinar E.

19. Powell GL, Stevens W. The use of conference microscopes 25. Sheets CG, Paquette IM. Practical applications of the
The assessment of unaided visual examination, intra·
for teaching histology. I Dent Educ 1984;48:566-567. clinical microscope in a restorative dental practice. Com·
1. Weathers A K . Access to success: Taking a closer look a t oral camera and operating microscope for the detection
20. Khayat BG. The use or magnification in endodontic pend Contin Educ Dent 2000;21:1084-1090.
magnification. Dent Today 2005;24:to6, 108-111. or occlusal caries lesions. Oper Dent 2005;30:t9cr194·
therapy. The operating microscope. Pract Periodontics 26. Burian MM, von Noorden GC. Burian-von Noorden's
2. van As G. Magnification and the alternatives for micro· 11. Behle C. Photography and the operating microscope in
Aesthet Dent 1998;10:137-144· Binocular Vision and Ocular Motility: Theory and anage
dentistry. Compend Contm Educ Dent 2001;22:10o8- dentistry. I (ali[ Dent Assoc 2001;29:765-771.
21. Carr GB. Magnification and illumination in endodontics. ment or Strabismus, ed 3 · St Louis: Mosby, 1985.
tOt2, 1014-1016. 12. Tibbetts LS, Shanelec DA. An overview of periodontal
In: Hardin I (ed). Clark's Clinical Dentistry, vol 4- St Louis: 27. Zoz Nl, Kuznetsov luA. Some health aspects of vision
). Garcia A. Dental magniication: A clear view of the pres· microsurgery. Curr Opin Periodontal 1994:187-193.
Mosby, 1998:1-14. during work with microscopes (in Russian]. Gig Tr Prof
ent and a close-up view of the future. Compend Cantin 13. Shanelec OA, Tibbetts LS. A perspective on the future of
22. Arens DE. Introduction to magniication in endodontics. Zabol 1972;16:5-9.
Educ Dent 205;26:459-463. periodontal microsurgery. Periodontal 2000 1996;11:
1 Esthet Restor Dent 2003;15:426-439. 28. Richards W. Instrument myopia-Microscopy. Am I
4· Caplan SA. agniication in dentistry. I Esthet Dent 58-64.
23. Sempira HN, Hatwell GR. Frequency or second mesio· Optom Physiol Opt 1976;53:658663.
1990;2:17-21. 14. Cortellini P. Tonetti MS. Microsurgical approach to peri·
buccal canals in maxillary molars as determined by use 29. Friedman MI. Landesman HM. Microscope-assisted pre
5 · Shanelec DA. Optical principles of loupes. I Calif Dent odontal regeneration. Initial evaluation in a case report.
of an operating microscope: A clinical study. I Endod cision (MAP) dentistry. A challenge for new knowledge.
Assoc 1992;20:25-32. 1 Periodontal 2001;4:559-569.
2000;26:673674· I (ali[ Dent Assoc 1998;26:90-905.
6. Millar Bl. Focus on loupes. Br Dent I 1998;185:504-508. 15. Tibbetts LS, Shanelec DA. Periodontal microsurgery. Dent
24. Pecora G, Andreana S. Use of dental operating micro·
7. Zaugg B. Stassinakis A. Holl P. lnnuence or magnifica Clin North Am 1998;42:339-359.
scopes in endodontic surgery. Oral Surg Oral ed Oral
tion tools on the recognition of simulated preparation 16. Whitehead SA. Wilson NH. Restorative decision-making
Pathol 1993;75:751-759.
and filling errors (in German� Schweiz Monatsschr behavior with magnification. Quintessence tnt 1992;23:
Zahnmed 2004; 114:89>-896. 667671.
8. Friedman M, ora AF, Schmidt R. Microscope-assisted 17. Sheets CG, Paquette IM. Hatate K. The clinical micro·
precision dentistry. Compend Conlin Educ Dent 1999; scope in an esthetic restorative practice. J Esthet Restor
20:723-7)6. Dent 2001;1):187-200.
9· Michaelides PL. USe of the operating microscope in 18. Winter RR, Cornell OF, Vingoren Gl, Patrick RB. Use of
dentistry. I calif Dent Assoc 1996;24:45-50. magnification in dental technology. I Esthet Restor Dent
2003;15:409-415;discussion 416.
2 3
CHAPTER 2
R E F E R E N CES 10. Erten H, Uctasli MB, Akarslan U, Uzun 0, Baspinar E.

19. Powell GL, Stevens W. The use of conference microscopes 25. Sheets CG, Paquette IM. Practical applications of the
The assessment of unaided visual examination, intra·
for teaching histology. I Dent Educ 1984;48:566-567. clinical microscope in a restorative dental practice. Com·
1. Weathers A K . Access to success: Taking a closer look a t oral camera and operating microscope for the detection
20. Khayat BG. The use or magnification in endodontic pend Contin Educ Dent 2000;21:1084-1090.
magnification. Dent Today 2005;24:to6, 108-111. or occlusal caries lesions. Oper Dent 2005;30:t9cr194·
therapy. The operating microscope. Pract Periodontics 26. Burian MM, von Noorden GC. Burian-von Noorden's
2. van As G. Magnification and the alternatives for micro· 11. Behle C. Photography and the operating microscope in
Aesthet Dent 1998;10:137-144· Binocular Vision and Ocular Motility: Theory and anage
dentistry. Compend Contm Educ Dent 2001;22:10o8- dentistry. I (ali[ Dent Assoc 2001;29:765-771.
21. Carr GB. Magnification and illumination in endodontics. ment or Strabismus, ed 3 · St Louis: Mosby, 1985.
tOt2, 1014-1016. 12. Tibbetts LS, Shanelec DA. An overview of periodontal
In: Hardin I (ed). Clark's Clinical Dentistry, vol 4- St Louis: 27. Zoz Nl, Kuznetsov luA. Some health aspects of vision
). Garcia A. Dental magniication: A clear view of the pres· microsurgery. Curr Opin Periodontal 1994:187-193.
Mosby, 1998:1-14. during work with microscopes (in Russian]. Gig Tr Prof
ent and a close-up view of the future. Compend Cantin 13. Shanelec OA, Tibbetts LS. A perspective on the future of
22. Arens DE. Introduction to magniication in endodontics. Zabol 1972;16:5-9.
Educ Dent 205;26:459-463. periodontal microsurgery. Periodontal 2000 1996;11:
1 Esthet Restor Dent 2003;15:426-439. 28. Richards W. Instrument myopia-Microscopy. Am I
4· Caplan SA. agniication in dentistry. I Esthet Dent 58-64.
23. Sempira HN, Hatwell GR. Frequency or second mesio· Optom Physiol Opt 1976;53:658663.
1990;2:17-21. 14. Cortellini P. Tonetti MS. Microsurgical approach to peri·
buccal canals in maxillary molars as determined by use 29. Friedman MI. Landesman HM. Microscope-assisted pre
5 · Shanelec DA. Optical principles of loupes. I Calif Dent odontal regeneration. Initial evaluation in a case report.
of an operating microscope: A clinical study. I Endod cision (MAP) dentistry. A challenge for new knowledge.
Assoc 1992;20:25-32. 1 Periodontal 2001;4:559-569.
2000;26:673674· I (ali[ Dent Assoc 1998;26:90-905.
6. Millar Bl. Focus on loupes. Br Dent I 1998;185:504-508. 15. Tibbetts LS, Shanelec DA. Periodontal microsurgery. Dent
24. Pecora G, Andreana S. Use of dental operating micro·
7. Zaugg B. Stassinakis A. Holl P. lnnuence or magnifica Clin North Am 1998;42:339-359.
scopes in endodontic surgery. Oral Surg Oral ed Oral
tion tools on the recognition of simulated preparation 16. Whitehead SA. Wilson NH. Restorative decision-making
Pathol 1993;75:751-759.
and filling errors (in German� Schweiz Monatsschr behavior with magnification. Quintessence tnt 1992;23:
Zahnmed 2004; 114:89>-896. 667671.
8. Friedman M, ora AF, Schmidt R. Microscope-assisted 17. Sheets CG, Paquette IM. Hatate K. The clinical micro·
precision dentistry. Compend Conlin Educ Dent 1999; scope in an esthetic restorative practice. J Esthet Restor
20:723-7)6. Dent 2001;1):187-200.
9· Michaelides PL. USe of the operating microscope in 18. Winter RR, Cornell OF, Vingoren Gl, Patrick RB. Use of
dentistry. I calif Dent Assoc 1996;24:45-50. magnification in dental technology. I Esthet Restor Dent
2003;15:409-415;discussion 416.
2 3
C H A P T E R 3
T O O T H P RE PARAT I O N F OR
C O M P L E TE C R O W N S
A X I A L . O C C L U S A L . A N D G I N G I V A L L I M I T S
ANATO M I C L I M ITS Devitalization of the tooth for this purpose is con

sidered overtreatment. 1
Prosthetic restoration involves a number of proce With respect to the occlusal limit, proper reduc·
dures designed to integrate the restoration in the tion of the occlusal or palatal surface of the tooth
patient's mouth in keeping with functional, esthetic, should not exceed limits of minimum tooth structure
and anatomic concerns. Tooth preparation is an es or adversely affect the masticatory function. This
sential pat of this process. The success of this pro limit depends on the relation of the pulp chamber to
cedure requires optimal use of various materials for the occlusal surface during reduction, and it some
impressions, restoration, and adhesion, exploiting times conflicts with the goal of achieving ideal thick
certain properties and minimizing others. Preparation ness for a ceramic or metal-ceramic prosthesis. One
requires controlled reduction of tooth form and vol of the most common errors committed during tooth
ume (Figs 3-1 to 3-3). Too much or too little thick preparation is insufficient reduction of the occlusal
ness or depth can initiate a series of imprecisions surface of prepared teeth (molars and premolars).
and errors that jeopardize the success of the particularly in the middle third of canines and in the
restoration. The clinician must be reasonably dex palatal area of incisors.
terous and, above all, have a clear vision of how to In a study of 25 canines prepared for restoration,
proceed with the tooth reduction while keeping in Zanetti et al' found the reduction too shallow in
mind the three fundamental anatomic limits: axial, Bs% of the cases, excessive in 15% of the cases, Fig 3-1 S i l i cone index positioned over a model of a maxillary central incisor. The longitudinally sectioned silicone index clearly illustrates
occlusal, and gingivaL and of average correct depth in only 10% of the the necessary reduction for a ceramic or ceramometal restoration. Use of a silicone index allows the clinician to define the proportions and
dimensions of the prosthetic tooth before beginning reduction to ensure the proper integration of the restoration.
The term axial limit refers to the consideration of cases. For 25% of the cases, the reduction did not
Figs 3-2 and 3-3 Examples of preparations with controlled reduction. The clinician can measure reduction with the diameter size of the b u rs
pulpal vitality. It is now widely accepted that reduc even reach a depth of o.s mm, a serious error for to preserve the overall shape of the prepared tooth and provide the necessary space for the restorative materiaL
ing a tooth for prosthetic purposes is compatible the longevity of the definitive restoration. To avoid Ftg 3-4 When the shape of the reduction tool impedes accurate measurement of the amount of tissue removed. a clinician may prepare the
tooth one half at a lime. as recommended by Mclean.3
with the integrity and health of the dental pulp. th i s problem when preparing the palatal area of _
Figs 3-5 and 3-6 Tooth extracted with periodontal tissue and sectioned using a microtome. The periodontal tissue. with its delicate structure.
must always be treated carefully during preparation and the positioning of the finish line.
4
S
C H A P T E R 3
T O O T H P RE PARAT I O N F OR
C O M P L E TE C R O W N S
A X I A L . O C C L U S A L . A N D G I N G I V A L L I M I T S
ANATO M I C L I M ITS Devitalization of the tooth for this purpose is con

sidered overtreatment. 1
Prosthetic restoration involves a number of proce With respect to the occlusal limit, proper reduc·
dures designed to integrate the restoration in the tion of the occlusal or palatal surface of the tooth
patient's mouth in keeping with functional, esthetic, should not exceed limits of minimum tooth structure
and anatomic concerns. Tooth preparation is an es or adversely affect the masticatory function. This
sential pat of this process. The success of this pro limit depends on the relation of the pulp chamber to
cedure requires optimal use of various materials for the occlusal surface during reduction, and it some
impressions, restoration, and adhesion, exploiting times conflicts with the goal of achieving ideal thick
certain properties and minimizing others. Preparation ness for a ceramic or metal-ceramic prosthesis. One
requires controlled reduction of tooth form and vol of the most common errors committed during tooth
ume (Figs 3-1 to 3-3). Too much or too little thick preparation is insufficient reduction of the occlusal
ness or depth can initiate a series of imprecisions surface of prepared teeth (molars and premolars).
and errors that jeopardize the success of the particularly in the middle third of canines and in the
restoration. The clinician must be reasonably dex palatal area of incisors.
terous and, above all, have a clear vision of how to In a study of 25 canines prepared for restoration,
proceed with the tooth reduction while keeping in Zanetti et al' found the reduction too shallow in
mind the three fundamental anatomic limits: axial, Bs% of the cases, excessive in 15% of the cases, Fig 3-1 S i l i cone index positioned over a model of a maxillary central incisor. The longitudinally sectioned silicone index clearly illustrates
occlusal, and gingivaL and of average correct depth in only 10% of the the necessary reduction for a ceramic or ceramometal restoration. Use of a silicone index allows the clinician to define the proportions and
dimensions of the prosthetic tooth before beginning reduction to ensure the proper integration of the restoration.
The term axial limit refers to the consideration of cases. For 25% of the cases, the reduction did not
Figs 3-2 and 3-3 Examples of preparations with controlled reduction. The clinician can measure reduction with the diameter size of the b u rs
pulpal vitality. It is now widely accepted that reduc even reach a depth of o.s mm, a serious error for to preserve the overall shape of the prepared tooth and provide the necessary space for the restorative materiaL
ing a tooth for prosthetic purposes is compatible the longevity of the definitive restoration. To avoid Ftg 3-4 When the shape of the reduction tool impedes accurate measurement of the amount of tissue removed. a clinician may prepare the
tooth one half at a lime. as recommended by Mclean.3
with the integrity and health of the dental pulp. th i s problem when preparing the palatal area of _
Figs 3-5 and 3-6 Tooth extracted with periodontal tissue and sectioned using a microtome. The periodontal tissue. with its delicate structure.
must always be treated carefully during preparation and the positioning of the finish line.
4
S
CHAPTER 3
Tooth Preparation for Complete Crowns
. incisors and canines, the clinician should reduce one axial surfaces. In 1955. )orgensen6 recommended a
half of a tooth at a time. Using this technique, de· value of 2 to 5 degrees, which was supported by
scribed by Mclean,3 a football contour point is used retention tests measuring tensile strength and con
to reduce one half of the tooth (Fig 3-4). By follow· firmed in 1994 by Wilson and Chan7 (Fig 3-7). These
ing this procedure, the clinician can make an imme recommended values for the TOC appear to be ideal
diate evaluation of the amount of dental structure values for maximum retention, though they are rarely
removed, even when using convex points, which do achieved in clinical practice. Indeed, the average
not permit measurement of the amount and depth TOC angle ranges from 12 to 27 degrees, with no ap·
of reduction. parent correlation to the level of experience of the
The gingiva/ limit is defined by an area known as clinicians sampled.s-1 1
the biologic width, a concept that is universally rec These studies underscore the influence of several
ognized but remains dificult to quantify numerical· factors on the TOC angle, including the type of tooth FIG 3-7 FIG 3-8
ly.4·S According to Gargiulo et al,4 the biologic width (anterior or posterior), the arch in which it is located
0 22 DEGREES
varies from tooth to tooth, but the authors report (maxilla or mandible), and the tooth surface being
the following average values: o.69 mm for the gin· prepared. The authors noted the following factors: TH E TOC ANGLE RAN G ES FROM 1 0 T
gival sulcus, 0.97 mm for the epithelial attachment,
and 1.07 mm for the connective tissue attachment, • Mandibular teeth had a greater TOC angle than
for a total biologic width of 2.04 mm (0.97 mm + maxillay teeth
1.07 mm). For prosthetic purposes, the biologic width • Posterior teeth had a greater TOC angle than an·
represents the minimum distance from the finish line terior teeth (Fig 3·8)
to the bone crest, and it must never be intruded • Buccolingual surfaces had a greater TOC angle
upon during the initial positioning of the finish line than mesiodistal surfaces
or by the prosthetic margin after cementation. If the • Monocular vision yielded a greater TOC than
biologic width is not preserved, the tissues react with binocular vision
chronic gingival inflammation and bone recession.
Therefore the clinician must stay within these limits to In defense of the TOC values obtained by clini
maintain healthy and stable gingival tissue (Figs 3·5 cians, some studies have offered a modified per·
and 3·6). spective.9·"·'3 Oodge et al'4 tested the resistance of
cemented crowns in teeth 10 mm in diameter and
SCIENTIFIC PRINCIPLES 3 - 5 mm in height with three diferent TOC angles.

The 22-degree angle proved inadequate in resisting
The clinical approach to tooth preparation for com· lateral forces, while no significant difference was
plete crowns must take into consideration certain noted between the IO· and 16-degree angles. The
scientific principles to ensure the biomechanical and authors concluded that 16 degrees was ideal, since
esthetic success of the restoration. One preparation to-degree angles are not easily achieved in clinical FIG 3-9 FIG 3-10
requisite that has attracted clinical interest is the practice. In 1997, Shillingburg et ai'S recommended
total occlusal convergence (TOQ, which is defined that the TOC angle should be confined to a range of Fig J-7 TOC of a prepared maxillary central incisor. The TOC. calculated by measuring the angle between the mesial and distal surfaces. is about 8
as the angle of convergence b etween two opposing 10 to 2 2 degrees (Figs 3·9 and 3·1o). .
degrees. This value is lower than optimal. according to several researchers 1·7
Fig3-8 TOC of a prepared posterior tooth. Posterior teeth have a greater TOC than do anterior teeth. and the angle formed by the buccal and palatal walls
is larger than that between the mesial and distal walls.
F1gs 3-g and 3·10 Examples of prepared teeth with optimal TOC angles \between 1 0 and 2 2 degrees) for prosthetic purposes.
11
CHAPTER 3
. incisors and canines, the clinician should reduce one axial surfaces. In 1955. )orgensen6 recommended a
half of a tooth at a time. Using this technique, de· value of 2 to 5 degrees, which was supported by
scribed by Mclean,3 a football contour point is used retention tests measuring tensile strength and con
to reduce one half of the tooth (Fig 3-4). By follow· firmed in 1994 by Wilson and Chan7 (Fig 3-7). These
ing this procedure, the clinician can make an imme recommended values for the TOC appear to be ideal
diate evaluation of the amount of dental structure values for maximum retention, though they are rarely
removed, even when using convex points, which do achieved in clinical practice. Indeed, the average
not permit measurement of the amount and depth TOC angle ranges from 12 to 27 degrees, with no ap·
of reduction. parent correlation to the level of experience of the
The gingiva/ limit is defined by an area known as clinicians sampled.s-1 1
the biologic width, a concept that is universally rec These studies underscore the influence of several
ognized but remains dificult to quantify numerical· factors on the TOC angle, including the type of tooth FIG 3-7 FIG 3-8
ly.4·S According to Gargiulo et al,4 the biologic width (anterior or posterior), the arch in which it is located
0 22 DEGREES
varies from tooth to tooth, but the authors report (maxilla or mandible), and the tooth surface being
the following average values: o.69 mm for the gin· prepared. The authors noted the following factors: TH E TOC ANGLE RAN G ES FROM 1 0 T
gival sulcus, 0.97 mm for the epithelial attachment,
and 1.07 mm for the connective tissue attachment, • Mandibular teeth had a greater TOC angle than
for a total biologic width of 2.04 mm (0.97 mm + maxillay teeth
1.07 mm). For prosthetic purposes, the biologic width • Posterior teeth had a greater TOC angle than an·
represents the minimum distance from the finish line terior teeth (Fig 3·8)
to the bone crest, and it must never be intruded • Buccolingual surfaces had a greater TOC angle
upon during the initial positioning of the finish line than mesiodistal surfaces
or by the prosthetic margin after cementation. If the • Monocular vision yielded a greater TOC than
biologic width is not preserved, the tissues react with binocular vision
chronic gingival inflammation and bone recession.
Therefore the clinician must stay within these limits to In defense of the TOC values obtained by clini
maintain healthy and stable gingival tissue (Figs 3·5 cians, some studies have offered a modified per·
and 3·6). spective.9·"·'3 Oodge et al'4 tested the resistance of
cemented crowns in teeth 10 mm in diameter and
SCIENTIFIC PRINCIPLES 3 - 5 mm in height with three diferent TOC angles.

The 22-degree angle proved inadequate in resisting
The clinical approach to tooth preparation for com· lateral forces, while no significant difference was
plete crowns must take into consideration certain noted between the IO· and 16-degree angles. The
scientific principles to ensure the biomechanical and authors concluded that 16 degrees was ideal, since
esthetic success of the restoration. One preparation to-degree angles are not easily achieved in clinical FIG 3-9 FIG 3-10
requisite that has attracted clinical interest is the practice. In 1997, Shillingburg et ai'S recommended
total occlusal convergence (TOQ, which is defined that the TOC angle should be confined to a range of Fig J-7 TOC of a prepared maxillary central incisor. The TOC. calculated by measuring the angle between the mesial and distal surfaces. is about 8
as the angle of convergence b etween two opposing 10 to 2 2 degrees (Figs 3·9 and 3·1o). .
degrees. This value is lower than optimal. according to several researchers 1·7
Fig3-8 TOC of a prepared posterior tooth. Posterior teeth have a greater TOC than do anterior teeth. and the angle formed by the buccal and palatal walls
is larger than that between the mesial and distal walls.
F1gs 3-g and 3·10 Examples of prepared teeth with optimal TOC angles \between 1 0 and 2 2 degrees) for prosthetic purposes.
11
CHAPTER 3
� Another study'6 showed that the most important is the use of boxes, grooves, or pin holes. 21 These
factor in the stability of the prosthetic restoration is secondary retentions must be constructed with
its resistance to lateral forces, rather than its inser regard to the dislocating forces, which differ accord
tion axis or TOC angle. The clinician must seek to ing to restoration type. For single crowns, the dislo I
cating forces are primarily buccolingual and the - ·

I
create convergence angles that are reproducible with
restorative materials and yet will ensure the lateral boxes and grooves must be placed on the proximal,
stability of the prosthetic restoration. The authors mesial, and distal surfaces. For fixed patial den
believe that an angle measuring between 10 and 20 tures, the forces are primarily mesiodistal and the
degrees will provide such stability. A TOC angle over retentive elements should be placed on the buccal
the limit leads to certain dislocation of the restora and lingual surfaces" (Figs 3-11 and 3-12).
tion,'7 but it is impossible to set a maximum limit In a literature review, Goodacre et ai'J list sever
since other variables, such as the height of the pre al preparation guidelines to ensure the mechanical, FIG 3-11
pared tooth, are involved in determining the stability. biologic, and esthetic success of a restoration.
Another point of clinical interest with regard to Among the principles listed are those regarding the
retention is the minimum occlusogingival height of preparation of the tooth in its entirety, including the
G R O O V E S M U ST B E P R E P A R E D TO O P P O S E T H E D I S P LA C E M E N T F O R C E S
the prepared tooth in relation to the angle of con TOC, the occlusogingival and incisogingival dimen
vergence. In an analysis of the stability of incisors sions, the relationship between the occlusogingival
and premolars with occlusogingival heights of 1, 2, dimension and the buccolingual dimension, and the
3, and 5 mm and a minimal TOC angle of 6 degrees, circumferential morphology. Other principles concern
Maxwell et al'8 concluded that the height must be at aspects of the inish line (le, its position, form, and
least 3 mm. Another study'9 introduced the concept depth in relation to the various restorative materi
of a critical TOC value over which a crown cannot als), the depth of axial and occlusaVincisal reduc
maintain adequate stability. The study indicated tion, the form of the linear angle, and the surface of
that, theoretically, stability criteria are met when a the prepared tooth.
molar 10 mm in diameter and 3 mm in occlusogin Their conclusions can be summarized as follows:
gival height has a TOC of 17-4 degrees or less.
Woolsey and Matich20 conirmed these data, con • The TOC angle should be between 10 and 20
cluding that a height of 3 mm is suficient if associ degrees.
ated with an angle of 10 degrees but insuficient • Recommended minimum heights are 4 mm for
with an angle of 20 degrees, which is common in prepared molars and 3 mm for other prepared
molars. For molars, the ideal occlusocervical height teeth. If the values are lower, axial grooves and
is 4 mm. boxes can be added to the proximal surface for
When working with convergence angles of 10 to single crowns or to the buccolingual areas for
20 degrees, the clinician should prepare incisors and fixed partial dentures.
premolars with a minimum occlusogingival height of • The occlusogingivaVbuccolingual dimension ratio FIG 3-12
3 mm and molars with a minimum height of 4 mm. should be equal to or greater than 0.4 mm.
When the clinician is faced with a clinical case in • Facioproximal and linguoproximal line angles
Figs 3-11 and 3-12 Retention grooves can be prepared on the mesial or distal walls for a single crown or on the buccal or palatal surfaces for a fixed
which more stability is needed in teeth that do not should be preserved whenever possible. Exces- partial denture. The grooves should create resistance against the dislocating forces. which have different vectors for a single crown (buccolingual) or
have the minimum dimensions, a viable alternative sive rounding is to be avoided. . a fixed partial denture (mesiodistal).
8
I
CHAPTER 3
� Another study'6 showed that the most important is the use of boxes, grooves, or pin holes. 21 These
factor in the stability of the prosthetic restoration is secondary retentions must be constructed with
its resistance to lateral forces, rather than its inser regard to the dislocating forces, which differ accord
tion axis or TOC angle. The clinician must seek to ing to restoration type. For single crowns, the dislo I
cating forces are primarily buccolingual and the - ·

I
create convergence angles that are reproducible with
restorative materials and yet will ensure the lateral boxes and grooves must be placed on the proximal,
stability of the prosthetic restoration. The authors mesial, and distal surfaces. For fixed patial den
believe that an angle measuring between 10 and 20 tures, the forces are primarily mesiodistal and the
degrees will provide such stability. A TOC angle over retentive elements should be placed on the buccal
the limit leads to certain dislocation of the restora and lingual surfaces" (Figs 3-11 and 3-12).
tion,'7 but it is impossible to set a maximum limit In a literature review, Goodacre et ai'J list sever
since other variables, such as the height of the pre al preparation guidelines to ensure the mechanical, FIG 3-11
pared tooth, are involved in determining the stability. biologic, and esthetic success of a restoration.
Another point of clinical interest with regard to Among the principles listed are those regarding the
retention is the minimum occlusogingival height of preparation of the tooth in its entirety, including the
G R O O V E S M U ST B E P R E P A R E D TO O P P O S E T H E D I S P LA C E M E N T F O R C E S
the prepared tooth in relation to the angle of con TOC, the occlusogingival and incisogingival dimen
vergence. In an analysis of the stability of incisors sions, the relationship between the occlusogingival
and premolars with occlusogingival heights of 1, 2, dimension and the buccolingual dimension, and the
3, and 5 mm and a minimal TOC angle of 6 degrees, circumferential morphology. Other principles concern
Maxwell et al'8 concluded that the height must be at aspects of the inish line (le, its position, form, and
least 3 mm. Another study'9 introduced the concept depth in relation to the various restorative materi
of a critical TOC value over which a crown cannot als), the depth of axial and occlusaVincisal reduc
maintain adequate stability. The study indicated tion, the form of the linear angle, and the surface of
that, theoretically, stability criteria are met when a the prepared tooth.
molar 10 mm in diameter and 3 mm in occlusogin Their conclusions can be summarized as follows:
gival height has a TOC of 17-4 degrees or less.
Woolsey and Matich20 conirmed these data, con • The TOC angle should be between 10 and 20
cluding that a height of 3 mm is suficient if associ degrees.
ated with an angle of 10 degrees but insuficient • Recommended minimum heights are 4 mm for
with an angle of 20 degrees, which is common in prepared molars and 3 mm for other prepared
molars. For molars, the ideal occlusocervical height teeth. If the values are lower, axial grooves and
is 4 mm. boxes can be added to the proximal surface for
When working with convergence angles of 10 to single crowns or to the buccolingual areas for
20 degrees, the clinician should prepare incisors and fixed partial dentures.
premolars with a minimum occlusogingival height of • The occlusogingivaVbuccolingual dimension ratio FIG 3-12
3 mm and molars with a minimum height of 4 mm. should be equal to or greater than 0.4 mm.
When the clinician is faced with a clinical case in • Facioproximal and linguoproximal line angles
Figs 3-11 and 3-12 Retention grooves can be prepared on the mesial or distal walls for a single crown or on the buccal or palatal surfaces for a fixed
which more stability is needed in teeth that do not should be preserved whenever possible. Exces- partial denture. The grooves should create resistance against the dislocating forces. which have different vectors for a single crown (buccolingual) or
have the minimum dimensions, a viable alternative sive rounding is to be avoided. . a fixed partial denture (mesiodistal).
8
I
CHAPTER 3
11 Conclusions regarding the finish line can be sum- Bur design

marized as follows:
Handpieces'S are classified according to the maxi
• The choice of finish line depends on the type of mum diameter of the bur, for example, a cone
restoration, the esthetic demands, the ease of shaped bur is classified by the maximum diameter
execution, and the clinician's experience. rather than by the diameter of the point, which is
• Esthetics and the condition of the prepared teeth considerably narrower. The handpiece is completed
determine the position of the finish line. The by a shank made of tempered stainless steel, which
supragingival position is most recommended. is corrosion-resistant and, above all, flex-resistant FIG 3-13 FIG 3-14 FIG 3-15
• Line angles should be rounded and well pol· even at high speeds.
ished. There are two categories of burs. The first essen
Fig 3-13 Fine-gril (30-�ml and coarse-grit (1 80-�ml burs. When not in motion the fine-grit bur appears to have a larger diameter.
tially performs a boring action and is usually made
Fig 3-14 Coarse-grit bur at rest.
The most important aspect, however, is that it is of tungsten carbide. The design of these burs is
F1g 3-15 Coarse-grit bur in motion. demonstrating a diameter equal to the fine-g rit bur.
dificult to scientifically correlate better marginal determined by the head shape (eg, cylindrical, con
adaptation with the various types of finish lines ical, inverted cone) and the geometric blade design'S
because results of comparative studies are biased (eg, surgical osteotrites used in implant surgery).
by the varied abilities and skills of dental techni Tungsten carbide burs are made of a sintered mate
cians who make the prostheses. rial of 90% tungsten carbide and 10% cobalt, which
acts as a binder, and they have a characteristic hard
ness value of 1,6oo (compare with the hardness value 11 cone}, but the abrasion layer is determined by the risk of breakage and maintain the integrity of the
ROTATING I N STRUMENTS
of 400 for stainless steel). The tungsten carbide bur random distribution of diamond grains on the bur. high-speed air turbine. The clinician must maintain
Before the practical aspects of tooth preparation can is attached by means of hydrostatic pressure, heat The diamond grains, selected by size, are bonded to congruity between the shape and total diameter of
be addressed, the required instruments should be (hot isostatic pressure [HIPD. and welding to the the bur head of the instrument through an electro the bur, depending on the grit of the abrasion layer
described to clariy their selection and proper use. neck of the instrument, which in turn is connected lytic bath, whereby two thirds of each grain be (coarse, medium, or fine). For example, a bur with a
Tooth preparation using rotating instruments must be to the stainless steel shank. The blade design of the come embedded in the nickel bonding compound. coarse grit should have a diameter that is smaller
carried out following a systematic process through bur may be helicoidal, transversal, straight, or cross Diamonds are used for abrasion because they have than that of a bur with a finer grit and yet still pre
out treatment. Every clinician must be completely cutting, with cutting and finishing options that vary a hardness superior to that of the surfaces to be serve optimal rigidity. To avoid excessive weakening
familiar with these instruments, which are used pri according to the clinical or laboratory application abraded. of the shank, coarse grits are most efective for burs
marily for abrasion. (eg, finishing of the tooth preparation, crown sepa The eficacy and quality of an abrasion bur are of reduced diameter, such as 0.14 mm, whereas
There is considerable debate as to the proper ration, cavity preparation, fabrication of resin crowns determined by the type of abrasion material, the extra-coarse grits are more efective for burs of 0.1B
shape, diameter, and blade design or grit of the bur. or removable partial dentures, casting, waxing, fin coaxiality and concentric rotation, the shape and mm diameter or larger. Burs with coarse- and extra
For example, one study24 incorrectly recommends ishing, and polishing). diameter of the bur. and the grit of the abrasion coarse grit will appear smaller than a bur with the
the use of sharp, medium-grit diamonds of small The second type of bur works with the abrasion layer. The coaxiality, or symmetry, of the bur controls same diameter but finer grit. Only during rotation is
diameter, claiming that this will ensure maximum of a diamond layer. Diamond burs also have a vari vibration accompanied by percussive efects and the it possible to see that the diameters are identical
conservation of dental tissue and pulp. ety of head shapes (eg, conical, cylindrical, inverted . bur's degree of precision. It also helps reduce the (Figs 3-13 to 3-15). ..
0
91
CHAPTER 3
11 Conclusions regarding the finish line can be sum- Bur design

marized as follows:
Handpieces'S are classified according to the maxi
• The choice of finish line depends on the type of mum diameter of the bur, for example, a cone
restoration, the esthetic demands, the ease of shaped bur is classified by the maximum diameter
execution, and the clinician's experience. rather than by the diameter of the point, which is
• Esthetics and the condition of the prepared teeth considerably narrower. The handpiece is completed
determine the position of the finish line. The by a shank made of tempered stainless steel, which
supragingival position is most recommended. is corrosion-resistant and, above all, flex-resistant FIG 3-13 FIG 3-14 FIG 3-15
• Line angles should be rounded and well pol· even at high speeds.
ished. There are two categories of burs. The first essen
Fig 3-13 Fine-gril (30-�ml and coarse-grit (1 80-�ml burs. When not in motion the fine-grit bur appears to have a larger diameter.
tially performs a boring action and is usually made
Fig 3-14 Coarse-grit bur at rest.
The most important aspect, however, is that it is of tungsten carbide. The design of these burs is
F1g 3-15 Coarse-grit bur in motion. demonstrating a diameter equal to the fine-g rit bur.
dificult to scientifically correlate better marginal determined by the head shape (eg, cylindrical, con
adaptation with the various types of finish lines ical, inverted cone) and the geometric blade design'S
because results of comparative studies are biased (eg, surgical osteotrites used in implant surgery).
by the varied abilities and skills of dental techni Tungsten carbide burs are made of a sintered mate
cians who make the prostheses. rial of 90% tungsten carbide and 10% cobalt, which
acts as a binder, and they have a characteristic hard
ness value of 1,6oo (compare with the hardness value 11 cone}, but the abrasion layer is determined by the risk of breakage and maintain the integrity of the
ROTATING I N STRUMENTS
of 400 for stainless steel). The tungsten carbide bur random distribution of diamond grains on the bur. high-speed air turbine. The clinician must maintain
Before the practical aspects of tooth preparation can is attached by means of hydrostatic pressure, heat The diamond grains, selected by size, are bonded to congruity between the shape and total diameter of
be addressed, the required instruments should be (hot isostatic pressure [HIPD. and welding to the the bur head of the instrument through an electro the bur, depending on the grit of the abrasion layer
described to clariy their selection and proper use. neck of the instrument, which in turn is connected lytic bath, whereby two thirds of each grain be (coarse, medium, or fine). For example, a bur with a
Tooth preparation using rotating instruments must be to the stainless steel shank. The blade design of the come embedded in the nickel bonding compound. coarse grit should have a diameter that is smaller
carried out following a systematic process through bur may be helicoidal, transversal, straight, or cross Diamonds are used for abrasion because they have than that of a bur with a finer grit and yet still pre
out treatment. Every clinician must be completely cutting, with cutting and finishing options that vary a hardness superior to that of the surfaces to be serve optimal rigidity. To avoid excessive weakening
familiar with these instruments, which are used pri according to the clinical or laboratory application abraded. of the shank, coarse grits are most efective for burs
marily for abrasion. (eg, finishing of the tooth preparation, crown sepa The eficacy and quality of an abrasion bur are of reduced diameter, such as 0.14 mm, whereas
There is considerable debate as to the proper ration, cavity preparation, fabrication of resin crowns determined by the type of abrasion material, the extra-coarse grits are more efective for burs of 0.1B
shape, diameter, and blade design or grit of the bur. or removable partial dentures, casting, waxing, fin coaxiality and concentric rotation, the shape and mm diameter or larger. Burs with coarse- and extra
For example, one study24 incorrectly recommends ishing, and polishing). diameter of the bur. and the grit of the abrasion coarse grit will appear smaller than a bur with the
the use of sharp, medium-grit diamonds of small The second type of bur works with the abrasion layer. The coaxiality, or symmetry, of the bur controls same diameter but finer grit. Only during rotation is
diameter, claiming that this will ensure maximum of a diamond layer. Diamond burs also have a vari vibration accompanied by percussive efects and the it possible to see that the diameters are identical
conservation of dental tissue and pulp. ety of head shapes (eg, conical, cylindrical, inverted . bur's degree of precision. It also helps reduce the (Figs 3-13 to 3-15). ..
0
91
CHAPTER 3 TAB L E 3 - 1 Characteristics of diamond b u rs with various grit levels
Tooth Preparation for Complete Crowns GRIT LEVEL
PARAMETER FINE COARSE
preparation. Table 3-1 shows that diamond burs wilh �

In the authors' opinion, the quality of lhe dia-
.
ABRASION LOW HIGH
mond burs is much more essential for selecting a coarse grits have greater abrasion and cut more effi· '"
manufacturer than the range of bur shapes and ciently, permitting the operator lo use a working
HIGHER LOW
designs. A high-quality abrasion handpiece has a grit force of aboul 100 g, 26- 27 while the working force
that is uniform in both size and shape. Allhough it that can be used with fine-grit burs is about 30 g.
WORKING JORCE LOW HIGHER
should have no bald spots, which would remove Some authors28•29 have shown that when a clinician ,..
material unevenly, the diamond layer should contain reduces a tooth using a fine-gril diamond bur with -
suficient water cooling,3° the increase in tooth tem
GENERATED•HEAi LIMITED LESS LIMITED
spaces that allow for the elimination of debris. . �
Burs are available in a vast array of shapes and perature is less than for burs with coarse and extra
diameters, but tooth preparation for prostheses coarse grits. Galindo and othersJ• analyzed the use
PRETIO. EFFECT LOW HIGHER
mostly requires large diameters that are easier for of burs with coarse and extra-coarse grit (12S and
J
FINISHING ., BETTER POOR
.'.ll
the operator to use, cause less lrauma to the pulp, 180 �m) and noted that the mean lemperature
and also function as measuring instruments. recorded during and after the cutting procedures
...
p..
The shape and peripheral definition of the tooth was lower than baseline temperature. WORKING TIME· LONGER SHORTER
preparation usually reflects the last application of A comparative study32 showed that the tooth tem
the bur on the tooth, during which the entire point perature rises an average of o.8°C with fine-grit burs, BUR ENDURANCE •··. HIGHER LOWER
·�
remains in contact with the tooth's longitudinal axis. 1.3°C with medium-grit burs, and t.S°C and 1.8°C with
Large-diameter burs are much easier to control than coarse- and extra-coarse-grit burs, respectively. How
smaller-diameter burs, and the correct preparation ever, the trials in this study were carried out by
shape can be deined with fewer applications. In making three successive cuts of o.8, o.s. and o.s mm
addition, the tooth temperature does not increase toward the tooth's center. In clinical practice, the clin
as much with large-diameter burs, thus protecting ician works the bur around the circumference of the .. iS reduced by SO%, 3S0fo, and 2S0/o for the three mond grains of 30 �m. are suitable only for inishing
the pulp. Large-diameter burs produce less heat tooth to progressively abrade the surface and never grades, respectively. the tooth preparation and should be used with very
because they develop greater peripheral velocity removes such thicknesses in one cut. A reduction in eficiency translates into a longer little cutting force to keep the tooth temperature from
and therefore dissipate more heat. This rule is ex All hough the conclusions of these in vitro exper working time, an increased working force applied by rising too much and damaging the pulp.
pressed through the following formula: iments are valid, the authors of this text argue in the operator, and a greater likelihood of clogging of
favor of the coarse- and extra-coarse-grit burs be the cutting edges of the diamonds. These factors
diameter of the tool X H i g h-speed handp ieces
no. of revolutions x T cause of the better cutting efficiency and debris lead to an increase in temperature, which in turn
Vp (peripheral velocity) �
elimination, which leads consequently to substan detrimentally affects the pulp. For this reason, a clin Clinicians must use high-speed instruments, either
K
tial decreases in the operating time and stress on ician should reduce teeth using coarse- and extra high-speed air turbine handpieces or handpieces
where K � 6o,ooo the tooth. Although the greater eficiency of burs coarse-grit burs, leaving the fine-grit burs exclusive with a torque multiplier. The high-speed air turbine
with coarse and extra-coarse grit is not widely rec ly for finishing the tooth preparation. handpiece, invented in the 196os, remains the most
With a high peripheral velocity, which is directly ognized,JJ Siegel and Von Fraunhofer34 have dis Because of their superior abrasion, coarse and commonly used instrument for tooth preparation,
proportional to the diameter of the bur, not only can cussed the importance of reduced operating times extra-coarse burs produce a very irregular surface especially in Mediterranean countries. However, this
heat dissipate more efficiently, but chips and shav and how efficiency decreases after the initial cut. with a high degree of surface roughness (Fig 3-16), instrument is being replaced by handpieces with
ings are eliminated more easily. Their study comparing diamond burs with medium, and they sufer more wear during use and must be torque multipliers (Fig 3·17). .
The correct use of rotating instruments must also coarse, and extra-coarse grit making three succes replaced relatively often. Fine-particle burs, with dia-
address grit selection and the techniques of tooth sive cuts shows that the eficiency of the third cut .
93
CHAPTER 3 TAB L E 3 - 1 Characteristics of diamond b u rs with various grit levels
Tooth Preparation for Complete Crowns GRIT LEVEL
PARAMETER FINE COARSE
preparation. Table 3-1 shows that diamond burs wilh �

In the authors' opinion, the quality of lhe dia-
.
ABRASION LOW HIGH
mond burs is much more essential for selecting a coarse grits have greater abrasion and cut more effi· '"
manufacturer than the range of bur shapes and ciently, permitting the operator lo use a working
HIGHER LOW
designs. A high-quality abrasion handpiece has a grit force of aboul 100 g, 26- 27 while the working force
that is uniform in both size and shape. Allhough it that can be used with fine-grit burs is about 30 g.
WORKING JORCE LOW HIGHER
should have no bald spots, which would remove Some authors28•29 have shown that when a clinician ,..
material unevenly, the diamond layer should contain reduces a tooth using a fine-gril diamond bur with -
suficient water cooling,3° the increase in tooth tem
GENERATED•HEAi LIMITED LESS LIMITED
spaces that allow for the elimination of debris. . �
Burs are available in a vast array of shapes and perature is less than for burs with coarse and extra
diameters, but tooth preparation for prostheses coarse grits. Galindo and othersJ• analyzed the use
PRETIO. EFFECT LOW HIGHER
mostly requires large diameters that are easier for of burs with coarse and extra-coarse grit (12S and
J
FINISHING ., BETTER POOR
.'.ll
the operator to use, cause less lrauma to the pulp, 180 �m) and noted that the mean lemperature
and also function as measuring instruments. recorded during and after the cutting procedures
...
p..
The shape and peripheral definition of the tooth was lower than baseline temperature. WORKING TIME· LONGER SHORTER
preparation usually reflects the last application of A comparative study32 showed that the tooth tem
the bur on the tooth, during which the entire point perature rises an average of o.8°C with fine-grit burs, BUR ENDURANCE •··. HIGHER LOWER
·�
remains in contact with the tooth's longitudinal axis. 1.3°C with medium-grit burs, and t.S°C and 1.8°C with
Large-diameter burs are much easier to control than coarse- and extra-coarse-grit burs, respectively. How
smaller-diameter burs, and the correct preparation ever, the trials in this study were carried out by
shape can be deined with fewer applications. In making three successive cuts of o.8, o.s. and o.s mm
addition, the tooth temperature does not increase toward the tooth's center. In clinical practice, the clin
as much with large-diameter burs, thus protecting ician works the bur around the circumference of the .. iS reduced by SO%, 3S0fo, and 2S0/o for the three mond grains of 30 �m. are suitable only for inishing
the pulp. Large-diameter burs produce less heat tooth to progressively abrade the surface and never grades, respectively. the tooth preparation and should be used with very
because they develop greater peripheral velocity removes such thicknesses in one cut. A reduction in eficiency translates into a longer little cutting force to keep the tooth temperature from
and therefore dissipate more heat. This rule is ex All hough the conclusions of these in vitro exper working time, an increased working force applied by rising too much and damaging the pulp.
pressed through the following formula: iments are valid, the authors of this text argue in the operator, and a greater likelihood of clogging of
favor of the coarse- and extra-coarse-grit burs be the cutting edges of the diamonds. These factors
diameter of the tool X H i g h-speed handp ieces
no. of revolutions x T cause of the better cutting efficiency and debris lead to an increase in temperature, which in turn
Vp (peripheral velocity) �
elimination, which leads consequently to substan detrimentally affects the pulp. For this reason, a clin Clinicians must use high-speed instruments, either
K
tial decreases in the operating time and stress on ician should reduce teeth using coarse- and extra high-speed air turbine handpieces or handpieces
where K � 6o,ooo the tooth. Although the greater eficiency of burs coarse-grit burs, leaving the fine-grit burs exclusive with a torque multiplier. The high-speed air turbine
with coarse and extra-coarse grit is not widely rec ly for finishing the tooth preparation. handpiece, invented in the 196os, remains the most
With a high peripheral velocity, which is directly ognized,JJ Siegel and Von Fraunhofer34 have dis Because of their superior abrasion, coarse and commonly used instrument for tooth preparation,
proportional to the diameter of the bur, not only can cussed the importance of reduced operating times extra-coarse burs produce a very irregular surface especially in Mediterranean countries. However, this
heat dissipate more efficiently, but chips and shav and how efficiency decreases after the initial cut. with a high degree of surface roughness (Fig 3-16), instrument is being replaced by handpieces with
ings are eliminated more easily. Their study comparing diamond burs with medium, and they sufer more wear during use and must be torque multipliers (Fig 3·17). .
The correct use of rotating instruments must also coarse, and extra-coarse grit making three succes replaced relatively often. Fine-particle burs, with dia-
address grit selection and the techniques of tooth sive cuts shows that the eficiency of the third cut .
93
CHAPTER 3
. The free-running speed of 30o,ooo to 40o,ooo with a diameter of 0.10 mm and a cylindrical shape
rpm produced by the high-speed air turbine drops (6879-314- 0IO [6 = grit, 879 = shape , 314 = friction
sharply as soon as the bur comes into contact with grip, 010 = diameter], Komet) is preferable to the
the tooth. In contrast, the handpiece with torque cone-shaped needle points with small diameters.
multiplier produces a free-running speed of 230,000 Needle point burs quickly lose diamond particles in
FIG 3-16 FIG J-17
rpm, which can be maintained during abrasion and the excessively fine tip, and their conical shape
adjusted to the lower speeds when necessary. The often creates conical tooth preparations with little
technology of the torque multiplier permits the oper retention, a defect that is dificult to correct in sub Fig 3-16 Fine- 130 �ml and coarse-grit 1 1 80 �ml b u rs seen under a stereomicroscope at high magnification 1 2 5 X ) .
ator to multiply the basic speed of 40,000 rpm by 4, sequent stages. Fig 3-17 Handpiece with torque multiplier a n d three water-spray jets f o r cooling. T h i s handpiece h a s a multiplication factor o f five.
s . or 5 - 7· increasing the speed to 16o,ooo, 2oo,ooo, The simultaneous preparation of multiple teeth
and 230,000 rpm, respectively. Two settings for the requires greater concentration of the clinician than
torque multiplier are used during tooth preparation. the preparation of a single tooth. If the multiple
The maximum multiplication setting is used for the restorations are to be connected, the prepared teeth
stages of separation and preliminary preparation, must have the same insertion path to ensure prop
while the lowest multiplication setting (4 multiplica· er prosthetic fit. Even in the case of unconnected
tions) is used for finishing. fixed restorations in which each tooth is restored
independently, proper parallelism is critical for limit
ing the subsequent stress and possible distortion of
Choosing the right instrument for tooth
preparation the impression materials (see chapter 9 for more
details about impressions). Therefore, when prepar
For didactic purposes, tooth preparation can be divid ing multiple teeth, the clinician must prepare each
ed into three sequential stages: separation, prelimi tooth before moving on to the next stage. Separa
nary preparation, and inishing. In each stage, dif tion, however, is performed only on the teeth adja
ferent burs and instruments are used to optimize cent to the preserved natural dentition. . at a rate of 44 m/minl 5 through three holes in the appear on the bur where only the binding substance
results while minimizing operator stress and the upper part of the handpiece. The convergence of the remains, the result would be pulpal damage. There
possibility of damaging the tooth. Prelim i nary preparation water on the working area reduces or eliminates the is currently no standard method for evaluating the
Preliminary preparation is the most demanding stage generated heatJ6 (Figs 3-20 and 3-21) . To optimize degree of wear of a bur; manufacturers rely on the
Separation because it establishes the conditions for the pros this stage, large-diameter burs (0.14, 0.16, and 0.18 sensitivity of the operator, an empirical criterion that
The critical separation stage requires great precision thetic outcome. The objective is to reduce the tooth mm) with the coarsest possible grit (180 �m) are is not without error.
to avoid causing i rreversible damage to adjacent in volume and shape and to correctly position the used to achieve the maximum efect with the least The authors' method is to change the b u rs fre
teeth and establishing inaccurate parallelism of the gingival margins (Figs 3-18 and 3-19). This stage is damage to the pulpal tissue (see Table 3-1). quently (every six to eight preparations) and make
prepared teeth. The use of a small-diameter cylin carried out using the torque multiplier at the mini Another i m portant factor i n minimizing trauma visual checks with magnifying instruments in two
drical bur is preferred for the interproximal zone. mum level of multiplication, and a working pressure during a dental preparation involves the wear of the ways. A static examination of wear is made by
Esthetic appearance is not crucial in this area, but at a maximum of 100 g. diamond abrasion layer, which is most significant checking the visible ratio of diamonds to binding
the clinician must create sufficient space for the During preliminay preparation of the dental tis with the coarsest grit. Wear manifests through the substance. A dynamic examination involves observ
preparation burs to place the buccopalatal grooves sue, the clinician must cool the working area with a loss of the diamond grains on the surface during ing the bur in motion, to ensure that the diamond
(see Figs 4-82 and 4-83). A chamfer diamond bur continuous jet of water. The water ideally is sprayed . rotation (Fig 3-22). I f use continues after bald spots grains produce the most uniform shape possible. .
"
CHAPTER 3
. The free-running speed of 30o,ooo to 40o,ooo with a diameter of 0.10 mm and a cylindrical shape
rpm produced by the high-speed air turbine drops (6879-314- 0IO [6 = grit, 879 = shape , 314 = friction
sharply as soon as the bur comes into contact with grip, 010 = diameter], Komet) is preferable to the
the tooth. In contrast, the handpiece with torque cone-shaped needle points with small diameters.
multiplier produces a free-running speed of 230,000 Needle point burs quickly lose diamond particles in
FIG 3-16 FIG J-17
rpm, which can be maintained during abrasion and the excessively fine tip, and their conical shape
adjusted to the lower speeds when necessary. The often creates conical tooth preparations with little
technology of the torque multiplier permits the oper retention, a defect that is dificult to correct in sub Fig 3-16 Fine- 130 �ml and coarse-grit 1 1 80 �ml b u rs seen under a stereomicroscope at high magnification 1 2 5 X ) .
ator to multiply the basic speed of 40,000 rpm by 4, sequent stages. Fig 3-17 Handpiece with torque multiplier a n d three water-spray jets f o r cooling. T h i s handpiece h a s a multiplication factor o f five.
s . or 5 - 7· increasing the speed to 16o,ooo, 2oo,ooo, The simultaneous preparation of multiple teeth
and 230,000 rpm, respectively. Two settings for the requires greater concentration of the clinician than
torque multiplier are used during tooth preparation. the preparation of a single tooth. If the multiple
The maximum multiplication setting is used for the restorations are to be connected, the prepared teeth
stages of separation and preliminary preparation, must have the same insertion path to ensure prop
while the lowest multiplication setting (4 multiplica· er prosthetic fit. Even in the case of unconnected
tions) is used for finishing. fixed restorations in which each tooth is restored
independently, proper parallelism is critical for limit
ing the subsequent stress and possible distortion of
Choosing the right instrument for tooth
preparation the impression materials (see chapter 9 for more
details about impressions). Therefore, when prepar
For didactic purposes, tooth preparation can be divid ing multiple teeth, the clinician must prepare each
ed into three sequential stages: separation, prelimi tooth before moving on to the next stage. Separa
nary preparation, and inishing. In each stage, dif tion, however, is performed only on the teeth adja
ferent burs and instruments are used to optimize cent to the preserved natural dentition. . at a rate of 44 m/minl 5 through three holes in the appear on the bur where only the binding substance
results while minimizing operator stress and the upper part of the handpiece. The convergence of the remains, the result would be pulpal damage. There
possibility of damaging the tooth. Prelim i nary preparation water on the working area reduces or eliminates the is currently no standard method for evaluating the
Preliminary preparation is the most demanding stage generated heatJ6 (Figs 3-20 and 3-21) . To optimize degree of wear of a bur; manufacturers rely on the
Separation because it establishes the conditions for the pros this stage, large-diameter burs (0.14, 0.16, and 0.18 sensitivity of the operator, an empirical criterion that
The critical separation stage requires great precision thetic outcome. The objective is to reduce the tooth mm) with the coarsest possible grit (180 �m) are is not without error.
to avoid causing i rreversible damage to adjacent in volume and shape and to correctly position the used to achieve the maximum efect with the least The authors' method is to change the b u rs fre
teeth and establishing inaccurate parallelism of the gingival margins (Figs 3-18 and 3-19). This stage is damage to the pulpal tissue (see Table 3-1). quently (every six to eight preparations) and make
prepared teeth. The use of a small-diameter cylin carried out using the torque multiplier at the mini Another i m portant factor i n minimizing trauma visual checks with magnifying instruments in two
drical bur is preferred for the interproximal zone. mum level of multiplication, and a working pressure during a dental preparation involves the wear of the ways. A static examination of wear is made by
Esthetic appearance is not crucial in this area, but at a maximum of 100 g. diamond abrasion layer, which is most significant checking the visible ratio of diamonds to binding
the clinician must create sufficient space for the During preliminay preparation of the dental tis with the coarsest grit. Wear manifests through the substance. A dynamic examination involves observ
preparation burs to place the buccopalatal grooves sue, the clinician must cool the working area with a loss of the diamond grains on the surface during ing the bur in motion, to ensure that the diamond
(see Figs 4-82 and 4-83). A chamfer diamond bur continuous jet of water. The water ideally is sprayed . rotation (Fig 3-22). I f use continues after bald spots grains produce the most uniform shape possible. .
"
CHAPTER 3
. Fintshing knows the anatomic and clinical aspects of the case
The last stage is finishing, which is usually performed and has a clear idea of the type of preparation
with a fine-grit bur, silicon carbide or Arkansas required for the restoration. Once these objectives
stones, polishing rubbers, and manual cutting tools have been established, the clinician can select a pre
(ie. rounded chisel). When finishing with rotating cise and effective procedure for a successful out·
instruments. the clinician should use the multiplier come. There are several step-by-step approaches to
torque at the lowest multiplication level and a tooth preparation that are designed to simpliy tooth
working force of 30 g. The aim is to make the sur reduction, including Stei n's guide-groove tech
faces smoother and more uniform. Any attempt to nique,J8 Mclean's reduction of half of the tooth at a
modify the shape of the prepared tooth would gen time,J and Martignoni and Schonenberger's slant·
erate excessive heat and damage the pulp. The cutting method.J9 Regardless of the technique, the FIG 3-18 FIG 3-19
authors use a fine-grit bur (30 �m) to finish the axial clinician must always keep anatomic references in
walls and the finish line (Fig 3-23). To make the fin mind and control the tooth reduction through an
ish line more regular. the authors use rounded chis awareness of the bur's diameter and the quantity of
els with suitable shapes and diameters (Fig 3-24). dental matter being removed.
Knowing the amount of material to remove is
possible by using a silicone index with a shore hard
SYSTEMATIZED TOOTH ness of 85 to 90 (Zetalabor, Zhermack).•0 A silicone

PREPARATION index is made on a diagnostic cast or waxup pre
pared in the laboratory. The clinician can use a sili
Tooth preparation is a clinical operation t h a t c a n be cone index that is properly cut longitudinally, hori
carried out successfully.J7 provided the clinician zontally, or serially (depending on the practical �
FIG 3-20 FIG 3-21 FIG 3-22
Fig l-18 At high magnification. the rough surface of the tooth prepared with the 1 80-�m-grit bur is evident.
ig 3-1 g Note the irregular profile resulting from the use of the 1 80-�m-grit bur.
Figs 3-20 Bur in motion with jets of water aimed at the point .
F1Q 3-21 8ur that does not provide adequate spray because of clogged or damaged water jets.
Fig 3;22 A worn bur (left) and a new one (right) of identical grit and shape. Coarse-grit burs are particularly subject to wear
as d1amond gra1ns tome loose.
Fig� 3-23 and 3-24 Prep ared tooth finished with a fine-grit bur and a manual chisel fDM1. Oeppeler). the ideal instruments for
_
rehn1ng the preparat1on.
16 FIG 3-23 FIG 3-24

CHAPTER 3
. Fintshing knows the anatomic and clinical aspects of the case
The last stage is finishing, which is usually performed and has a clear idea of the type of preparation
with a fine-grit bur, silicon carbide or Arkansas required for the restoration. Once these objectives
stones, polishing rubbers, and manual cutting tools have been established, the clinician can select a pre
(ie. rounded chisel). When finishing with rotating cise and effective procedure for a successful out·
instruments. the clinician should use the multiplier come. There are several step-by-step approaches to
torque at the lowest multiplication level and a tooth preparation that are designed to simpliy tooth
working force of 30 g. The aim is to make the sur reduction, including Stei n's guide-groove tech
faces smoother and more uniform. Any attempt to nique,J8 Mclean's reduction of half of the tooth at a
modify the shape of the prepared tooth would gen time,J and Martignoni and Schonenberger's slant·
erate excessive heat and damage the pulp. The cutting method.J9 Regardless of the technique, the FIG 3-18 FIG 3-19
authors use a fine-grit bur (30 �m) to finish the axial clinician must always keep anatomic references in
walls and the finish line (Fig 3-23). To make the fin mind and control the tooth reduction through an
ish line more regular. the authors use rounded chis awareness of the bur's diameter and the quantity of
els with suitable shapes and diameters (Fig 3-24). dental matter being removed.
Knowing the amount of material to remove is
possible by using a silicone index with a shore hard
SYSTEMATIZED TOOTH ness of 85 to 90 (Zetalabor, Zhermack).•0 A silicone

PREPARATION index is made on a diagnostic cast or waxup pre
pared in the laboratory. The clinician can use a sili
Tooth preparation is a clinical operation t h a t c a n be cone index that is properly cut longitudinally, hori
carried out successfully.J7 provided the clinician zontally, or serially (depending on the practical �
FIG 3-20 FIG 3-21 FIG 3-22
Fig l-18 At high magnification. the rough surface of the tooth prepared with the 1 80-�m-grit bur is evident.
ig 3-1 g Note the irregular profile resulting from the use of the 1 80-�m-grit bur.
Figs 3-20 Bur in motion with jets of water aimed at the point .
F1Q 3-21 8ur that does not provide adequate spray because of clogged or damaged water jets.
Fig 3;22 A worn bur (left) and a new one (right) of identical grit and shape. Coarse-grit burs are particularly subject to wear
as d1amond gra1ns tome loose.
Fig� 3-23 and 3-24 Prep ared tooth finished with a fine-grit bur and a manual chisel fDM1. Oeppeler). the ideal instruments for
_
rehn1ng the preparat1on.
16 FIG 3-23 FIG 3-24

CHAPTER 3
4 needs of the operator), to evaluate the tooth prepa bur to access the entire occlusal surface, including
ration and determine what remains to be done (Figs the lingual aspect. The object is to prepare the difi
3-25 to 3-28). cult lingual side with as much precision as the buc
The initial stage of preparation consists of sepa cal side (Figs 3-33 to 3-36). The authors prefer con
rating the preserved natural dentition from the teeth ical burs to the barrel contour burs because they are
to be restored by using a thin cylindrical bur and a more practical and versatile; the barrel contour bur
FIG 3-25 FIG 3-26
chamfer with a diameter of 0.10 (6879 - 314 - 010) (Fig is often incongruent with the occlusal morphology of
3-29). Special care must be taken to protect the the teeth. In the case of incisors and canines. the
interproximal area, preventing any lesions to the palatal surface is prepared with a football contour
adjacent teeth or gingiva. The gingival reference bur, using the Mclean techniquel to reduce half of
must never be lost; extending the preparation the tooth at a time (Figs 3-37 and 3-38).
beyond the gingival margin not only damages the The clinician need not reproduce all the crests,
soft tissue, but also loses the positional reference. grooves, and other features of the occlusal anatomy;
Another important element is the overall efficien two ridges and a groove are sufficient. Excessive
cy of the preparation. The operator should complete sculpting of the occlusal surface could lead to a lack
each clinical stage before proceeding, since each of correspondence during occlusion. with areas of
stage is preparatory for the next step. An incorrect or the restoration presenting insufficient thickness.
incomplete procedure would require the operator to Finally, the clinician may round the palatal and buc
change burs several times to complete the next cal surfaces for the insertion of the prosthesis, or,
stage, thus disrupting the clinician's concentration. according to Kuwata's three-plane theory,•' to create
After separation, the clinician must position the the requi red space for the restoration buildup in
buccal and palatal margins with a guide groove. The shape and thickness (Figs 3-39 to 3-41).
operator places the groove with the bur slanted, The finish line is repositioned only after the FIG 3-27 FIG 3-28
careful to avoid contact with the gingiva or the sur retraction cord (no. ooo or no. oo) has been placed.
face of the middle third of the tooth (Fig 3-30). The anatomy of the gingiva and the technique of
According to Stein's technique,l8 other grooves using retraction cords (see chapter 6) determines to
are made on the buccal and palatal surfaces (Fig 3- what extent the restoration margin can be posi
31) to the desired depth. If the preparation is being tioned subgingivally. The thickness of the cord deter
made with a so-degree shoulder bur or a chamfer mines the amount of vertical retraction, and the pre
bur, the depth is half the width of the instrument. cision of the gingival retraction dictates the subgin
After the first groove is made, the second is pre gival restoration margin. Once the impression has
pared by leaning on the first guide groove and been made and the cord has been removed, the gin
matching the inclination of the tooth. The reduction giva should return to its normal level prior to the Fig 3-25 Silicone index of a shore hardness of 85 (Zetalaborl made directly on the diagnostic waxup or cast. These functional guides can be
of the tooth surface is then completed according to insertion of the cord. sectioned to determine the volumes of the various longitudinal or horizontal planes.
the limits set by the Stein grooves. The controlled Fig 3-26 1ndex has been sectioned horizontally with cuts at 2-mm intervals. leaving the peripheral portion intact. to help ualyze buccal reduc
Gingival retraction gives the clinician access to
tion at the apical. middle. and coronal levels.
procedure results in a uniform reduction of tooth reposition the finish line to a subgingival level. For Fig 3-27 Horizontal section of a silicone index. It is possible to make other index sections. for instance. by removing the buccal area entirely
volume and thickness (Fig 3-32). about a decade, the authors have performed reposi but leaving 1 to 2 mm of the incisal area on the buccal side. or by sectioning only the incisal portion. yielding an indirect view of available
space.
The clinician reduces the occlusal surface of the tioning using sonic or ultrasonic oscillating instru
Fig 3-28 Longitudinal section of a silicone index. Positioned at the midpoint of the tooth. the index provides exact values for the buccal. palatal.
tooth with a large-diameter, short conical diamond ments. These nonrotating instruments do not dam- .. and incisal reduction.
I
"
CHAPTER 3
4 needs of the operator), to evaluate the tooth prepa bur to access the entire occlusal surface, including
ration and determine what remains to be done (Figs the lingual aspect. The object is to prepare the difi
3-25 to 3-28). cult lingual side with as much precision as the buc
The initial stage of preparation consists of sepa cal side (Figs 3-33 to 3-36). The authors prefer con
rating the preserved natural dentition from the teeth ical burs to the barrel contour burs because they are
to be restored by using a thin cylindrical bur and a more practical and versatile; the barrel contour bur
FIG 3-25 FIG 3-26
chamfer with a diameter of 0.10 (6879 - 314 - 010) (Fig is often incongruent with the occlusal morphology of
3-29). Special care must be taken to protect the the teeth. In the case of incisors and canines. the
interproximal area, preventing any lesions to the palatal surface is prepared with a football contour
adjacent teeth or gingiva. The gingival reference bur, using the Mclean techniquel to reduce half of
must never be lost; extending the preparation the tooth at a time (Figs 3-37 and 3-38).
beyond the gingival margin not only damages the The clinician need not reproduce all the crests,
soft tissue, but also loses the positional reference. grooves, and other features of the occlusal anatomy;
Another important element is the overall efficien two ridges and a groove are sufficient. Excessive
cy of the preparation. The operator should complete sculpting of the occlusal surface could lead to a lack
each clinical stage before proceeding, since each of correspondence during occlusion. with areas of
stage is preparatory for the next step. An incorrect or the restoration presenting insufficient thickness.
incomplete procedure would require the operator to Finally, the clinician may round the palatal and buc
change burs several times to complete the next cal surfaces for the insertion of the prosthesis, or,
stage, thus disrupting the clinician's concentration. according to Kuwata's three-plane theory,•' to create
After separation, the clinician must position the the requi red space for the restoration buildup in
buccal and palatal margins with a guide groove. The shape and thickness (Figs 3-39 to 3-41).
operator places the groove with the bur slanted, The finish line is repositioned only after the FIG 3-27 FIG 3-28
careful to avoid contact with the gingiva or the sur retraction cord (no. ooo or no. oo) has been placed.
face of the middle third of the tooth (Fig 3-30). The anatomy of the gingiva and the technique of
According to Stein's technique,l8 other grooves using retraction cords (see chapter 6) determines to
are made on the buccal and palatal surfaces (Fig 3- what extent the restoration margin can be posi
31) to the desired depth. If the preparation is being tioned subgingivally. The thickness of the cord deter
made with a so-degree shoulder bur or a chamfer mines the amount of vertical retraction, and the pre
bur, the depth is half the width of the instrument. cision of the gingival retraction dictates the subgin
After the first groove is made, the second is pre gival restoration margin. Once the impression has
pared by leaning on the first guide groove and been made and the cord has been removed, the gin
matching the inclination of the tooth. The reduction giva should return to its normal level prior to the Fig 3-25 Silicone index of a shore hardness of 85 (Zetalaborl made directly on the diagnostic waxup or cast. These functional guides can be
of the tooth surface is then completed according to insertion of the cord. sectioned to determine the volumes of the various longitudinal or horizontal planes.
the limits set by the Stein grooves. The controlled Fig 3-26 1ndex has been sectioned horizontally with cuts at 2-mm intervals. leaving the peripheral portion intact. to help ualyze buccal reduc
Gingival retraction gives the clinician access to
tion at the apical. middle. and coronal levels.
procedure results in a uniform reduction of tooth reposition the finish line to a subgingival level. For Fig 3-27 Horizontal section of a silicone index. It is possible to make other index sections. for instance. by removing the buccal area entirely
volume and thickness (Fig 3-32). about a decade, the authors have performed reposi but leaving 1 to 2 mm of the incisal area on the buccal side. or by sectioning only the incisal portion. yielding an indirect view of available
space.
The clinician reduces the occlusal surface of the tioning using sonic or ultrasonic oscillating instru
Fig 3-28 Longitudinal section of a silicone index. Positioned at the midpoint of the tooth. the index provides exact values for the buccal. palatal.
tooth with a large-diameter, short conical diamond ments. These nonrotating instruments do not dam- .. and incisal reduction.
I
"
CHAPTER 3
Fig 3-31 Central buccal reduction grooves as recommended by Stein.31 Knowing the diameter and size of the bur. the amount of the initial
reduction can be determined by making vertical notches in the tooth. start1ng from the gu1de groove made previOusly.
Fig 3-32 Preparation proceeds to even out the rest of the palatal and buccal surfaces with the reduction grooves. always starting from the
guide groove.
Fig 3-33 Reduction of the occlusal surface of the tooth. B y reducing the surface one half at a time. the clinician can visualize the extent of the
reduction.
Figs 3-34 and 3-35 Note how the occlusal reference points are maintained.
Fig 3-36 Barrel contour bur used for the o c clusal reduction. The authors prefer to use a short conical bur with a diameter of 2 . 5 mm.
Fig 3-2g Separation of the tooth. Using metal matrices and wooden wedges as separators. care is taken not to impact the integrity of the neigh Figs 3-37 and 3-38 Tooth preparation using football contour burs. The palatal surface of an anterior tooth is prepared with a coarse-grit bur fol
boring tooth. For this stage. the authors prefer to use a cylindrical bur with a small diameter 10.10 mm) rather than a needle-point bur. which
lowed by a fine-grit bur. reducing one half of the tooth at a time.
wears down rapidly at the tip and can make the walls too conical.
Fig 3-30 A g o-degree guide groove made while keeping the bur in an undercut direction. A chamfer. 50-degree. or round bur could also be
used. The purpose of this step is to make a distinct line to mark the start of the preparation so that it is above the gingival margin and not
touching the soft tissues. This is done on both the buccal and palatal surfaces. Normally the authors use a modified chamfer bur.
10
101
CHAPTER 3
Fig 3-31 Central buccal reduction grooves as recommended by Stein.31 Knowing the diameter and size of the bur. the amount of the initial
reduction can be determined by making vertical notches in the tooth. start1ng from the gu1de groove made previOusly.
Fig 3-32 Preparation proceeds to even out the rest of the palatal and buccal surfaces with the reduction grooves. always starting from the
guide groove.
Fig 3-33 Reduction of the occlusal surface of the tooth. B y reducing the surface one half at a time. the clinician can visualize the extent of the
reduction.
Figs 3-34 and 3-35 Note how the occlusal reference points are maintained.
Fig 3-36 Barrel contour bur used for the o c clusal reduction. The authors prefer to use a short conical bur with a diameter of 2 . 5 mm.
Fig 3-2g Separation of the tooth. Using metal matrices and wooden wedges as separators. care is taken not to impact the integrity of the neigh Figs 3-37 and 3-38 Tooth preparation using football contour burs. The palatal surface of an anterior tooth is prepared with a coarse-grit bur fol
boring tooth. For this stage. the authors prefer to use a cylindrical bur with a small diameter 10.10 mm) rather than a needle-point bur. which
lowed by a fine-grit bur. reducing one half of the tooth at a time.
wears down rapidly at the tip and can make the walls too conical.
Fig 3-30 A g o-degree guide groove made while keeping the bur in an undercut direction. A chamfer. 50-degree. or round bur could also be
used. The purpose of this step is to make a distinct line to mark the start of the preparation so that it is above the gingival margin and not
touching the soft tissues. This is done on both the buccal and palatal surfaces. Normally the authors use a modified chamfer bur.
10
101
CHAPTER 3
Principles of Preparation for Complete Crowns
� age gingival tissue and are easier to control, result· preparation (ie, separation, preliminary preparation,
ing in a more precise finish line (see chapter s). and finishing) involves different priorities and foci.
The next stage is finishing, which is performed A level of concentration (medium, medium-high, or
using fine-grit (Jo �m) diamond burs and roughing high) can be assigned to each factor of tooth prepa
stones of the same diameter. Roughing stones (sili ration based on the stage of preparation and the
FIG 3-39 FIG 3-40
con carbide and Arkansas). can be modified in shape objectives (Fig 3-48). During the separation stage,
and size according to the operator's needs (Figs 3-42 concentration must be medium-high with respect to
to 3-44). Perfect shoulder polishing can be achieved parallelism and medium for the tooth form and the
only through the use of manual chisels of appropri execution of the finish line. In the primary reduction
ate size and shape. Rounded chisels work via traction stage, the level of concentration should be high for
in a clockwise and counterclockwise direction and are parallelism and tooth form and medium-high for the
easy to use, permitting precise completion of the fin· finish line. In the finishing stage, which is completed
ish line (Figs 3-45 and 3-46). at low speed, maximum concentration is required for
polishing and finishing of the shoulder and for com
pleting the finish line. Parallelism is already estab
SELECTIVE CO NCENTRATION
lished at this point and requires little attention. In
FIG 3-41 FIG 3-42
T h e clinician must set t h e correct handpiece speed this way, the necessary level of concentration can be
and choose burs with cutting or abrasion properties focused on the principal objective of each stage,
to best address the specific task at hand and suc rather than concentrating equally on each factor, at
cessfully complete all stages of tooth preparation (Fig all times. Selective attention helps the practitioner
3-47). These operating principles require the constant avoid fatigue and lapses in concentration and con-
focused concentration of the clinician. Each stage of tributes to the success of tooth preparation. •
FIG 3-43 FIG 3-4
fig 3-3g Buccal and palatal surfaces are rounded holding the bur at a 45-degree angle to the tooth's longitudinal axis.
figs 3-0 and 3-41 Preliminary preparation has provided adequate volume for the restorative materials. Note the presence of
rough surfaces and sharp edges. from the occlusal mw. note the favorable spacing of the prepared tooth and the total visi
bility of the shoulder mcumference. free of the shaded areas that i n dicate undercuts.
fig 3-41 finishing stage of preparation carried out using fine-grit diamond burs or silicon carbide or corundum stones.
figs 3-43 and3-44 A clin ician may customize the torm of Arkansas burs by direct abrasion on a stone of greater hardness. adapt
Ing thm shape and me _ to match
the spaces 1n the finiSh line obtained during preliminary preparation.
figs 3;45 and 3-4i The last instrument needed for smoothing the surface is the rounded chisel. which can be used on
every sur
face 1n a clockwiSe and counterclockwise direction. Note the degree of smoothness on the finish tine obtained FIG 3-45 FIG 3-46
through the use
of the rounded chiSel.
12
tl3
CHAPTER 3
Principles of Preparation for Complete Crowns
� age gingival tissue and are easier to control, result· preparation (ie, separation, preliminary preparation,
ing in a more precise finish line (see chapter s). and finishing) involves different priorities and foci.
The next stage is finishing, which is performed A level of concentration (medium, medium-high, or
using fine-grit (Jo �m) diamond burs and roughing high) can be assigned to each factor of tooth prepa
stones of the same diameter. Roughing stones (sili ration based on the stage of preparation and the
FIG 3-39 FIG 3-40
con carbide and Arkansas). can be modified in shape objectives (Fig 3-48). During the separation stage,
and size according to the operator's needs (Figs 3-42 concentration must be medium-high with respect to
to 3-44). Perfect shoulder polishing can be achieved parallelism and medium for the tooth form and the
only through the use of manual chisels of appropri execution of the finish line. In the primary reduction
ate size and shape. Rounded chisels work via traction stage, the level of concentration should be high for
in a clockwise and counterclockwise direction and are parallelism and tooth form and medium-high for the
easy to use, permitting precise completion of the fin· finish line. In the finishing stage, which is completed
ish line (Figs 3-45 and 3-46). at low speed, maximum concentration is required for
polishing and finishing of the shoulder and for com
pleting the finish line. Parallelism is already estab
SELECTIVE CO NCENTRATION
lished at this point and requires little attention. In
FIG 3-41 FIG 3-42
T h e clinician must set t h e correct handpiece speed this way, the necessary level of concentration can be
and choose burs with cutting or abrasion properties focused on the principal objective of each stage,
to best address the specific task at hand and suc rather than concentrating equally on each factor, at
cessfully complete all stages of tooth preparation (Fig all times. Selective attention helps the practitioner
3-47). These operating principles require the constant avoid fatigue and lapses in concentration and con-
focused concentration of the clinician. Each stage of tributes to the success of tooth preparation. •
FIG 3-43 FIG 3-4
fig 3-3g Buccal and palatal surfaces are rounded holding the bur at a 45-degree angle to the tooth's longitudinal axis.
figs 3-0 and 3-41 Preliminary preparation has provided adequate volume for the restorative materials. Note the presence of
rough surfaces and sharp edges. from the occlusal mw. note the favorable spacing of the prepared tooth and the total visi
bility of the shoulder mcumference. free of the shaded areas that i n dicate undercuts.
fig 3-41 finishing stage of preparation carried out using fine-grit diamond burs or silicon carbide or corundum stones.
figs 3-43 and3-44 A clin ician may customize the torm of Arkansas burs by direct abrasion on a stone of greater hardness. adapt
Ing thm shape and me _ to match
the spaces 1n the finiSh line obtained during preliminary preparation.
figs 3;45 and 3-4i The last instrument needed for smoothing the surface is the rounded chisel. which can be used on
every sur
face 1n a clockwiSe and counterclockwise direction. Note the degree of smoothness on the finish tine obtained FIG 3-45 FIG 3-46
through the use
of the rounded chiSel.
12
tl3
CHAPTER l
w
� � w
n
t '
1 1 Fin i s h i g
( (
: :
.. ..
Separation Reduct1on Margm repos•t•on1ng Fmal flmshmg
Handptece
spud
Level
Handp'ec'
speed
l Level Level Lew!
-+ +
Speed Speed
$" 1 $" �
NA NA
0000
NA
Form 0 NA
000
F1msh tme
L
post lion pOSitiOn
Key
Ultrasonic
00000
0100 = Med1um concentrat•on tnstrument
00 0I00 0 0 = Med1um-h1gh concentration

Some
= High concentration tnstrument
00000
NA 0000
Rounded
ChiSel
Save e n e rgy u s i n g :
• Clea r o bj ectives
Fig 3-47 Maxillary premolar and molar prepared for complete crowns. All stages of preparation are complete.
• Syst e m a t i c p roce d u re s
• S e lective c o n c e n t ra t i o n
Fig 3-48 Diagram illustrating the selective concentration needed during the various stages o f preparation. The objective i s t o avoid fatigue b y focusing
on the task at hand requiring the most attention. NA = not applicable.
14
105
CHAPTER l
w
� � w
n
t '
1 1 Fin i s h i g
( (
: :
.. ..
Separation Reduct1on Margm repos•t•on1ng Fmal flmshmg
Handptece
spud
Level
Handp'ec'
speed
l Level Level Lew!
-+ +
Speed Speed
$" 1 $" �
NA NA
0000
NA
Form 0 NA
000
F1msh tme
L
post lion pOSitiOn
Key
Ultrasonic
00000
0100 = Med1um concentrat•on tnstrument
00 0I00 0 0 = Med1um-h1gh concentration

Some
= High concentration tnstrument
00000
NA 0000
Rounded
ChiSel
Save e n e rgy u s i n g :
• Clea r o bj ectives
Fig 3-47 Maxillary premolar and molar prepared for complete crowns. All stages of preparation are complete.
• Syst e m a t i c p roce d u re s
• S e lective c o n c e n t ra t i o n
Fig 3-48 Diagram illustrating the selective concentration needed during the various stages o f preparation. The objective i s t o avoid fatigue b y focusing
on the task at hand requiring the most attention. NA = not applicable.
14
105
CHAPTER 3
12. Lempoel Pi. Snoek PA. van1 Hof M. Lemmens Pl. The 2z. Wiskott HW, Nicholls 11. Belser UC. The efect of tooth 32. Ottl P, Lauer HC. Temperature response in the pulpal
REFERENCES
convergence angle of crown preparations with clinically preparation height and diameter on the resistance of chamber during ultrahigh-speed tooth preparation with
1. Kois JC. New paradigms for anterior tooth preparation. satisactorv retention [in Dutch[. Ned Tijdschr Tand· complete crowns to atigue loading. lnt J Prosthodont diamond burs of diferent grit. I Prosthet Dent 1998;
Rationale and technique. Oral Health 1998;88:19-30. heelkd 1993;100:336-338. 1997;10:207-215. 80:12-19.
2. Zanetti AL, engar A. Novelli MD. Lagana DC. Thick· 13. Mou SH. Chai T, Wang )S. Shiau Y. Influence of difer 23. Goodacre CJ. Campagni V, Aquilino SA. Tooth prepa· 33. )ung M, Pantke H . The efect of diamond grinding instru
ness of the remaining enamel after preparation of cin ent convergence angles and tooth preparation heights rations for complete crowns: An art form based on sci ment of diferent grit on dental hard tissue [in Genman].
gulum rest seats on maxillay canines. I Prosthet Dent on the internal adaptation of Cerec crowns. J Prosthet entiic principles. I Prosthet Dent 2001;85:363-376. Dtsch Stomatal 1991;41:32>-322.
1998;8o:31-322. Dent 2002;87=24&-255· 24. Kimmel K. Veahren und Probleme der oralmedizinischen 34· Siegel SC, Von Fraunhofer JA. Cutting eiciency of three
3· Mclean JW. The Science and M of Dental Ceramics. 14. Dodge W. Weed RM. Baez RJ. Buchanan RN. The efect Prlparationstechnik. Quintessenz 2001;52:873-883. diamond bur grit sizes. J Am Dent Assoc 200;131:
Chicago: Quintessence. 1979. of convergence angle on retention and resistance form. 25. Glossav of Prosthodontic Tenms. I Prosthet Dent 2005; 1706-1710.
4. Gargiulo AW. Wentz FM. Orban 81. Dimensions and rela· Quintessence lnt 1985;16:191-194. 94:192. 35· von Fraunhofer )A. Siegel SC. Feldman S. Handpiece
tion of the dentogingival junction in humans. J Peri 15. Shillingburg HT. Hobo S. Whitsett LD. Jacobi R, Brackett 26. Siegel SC, von Fraunhofer JA. Dental cutting with dia· coolant Row rates and dental cutting. Oper Dent 2000:
odontal 1961;32:261-267. SE. Fundamentals of Fixed Prosthodontics, ed 3· Chi· mond burs: Heavy·handed or light-touch? I Prosthodont 25:544-548.
5· Ingber JS, Rose LF, Coslet JG. The "biologic width"-A cago: Quintessence. 1997. 1999:8:39· 36. Ozturk B, Usumez A. Ozturk AN, Ozer . In vitro assess
concept in periodontics and restorative dentistry. Alpha 16. Wiskott HW. Nicholls II, Belser UC. The relationship 27. Elias K, Am is A. Setchell OJ. The magnitude of cutting ment of temperature change in the pulp chamber dur·
Omegan 1977;70:62�5. between abutment taper and resistance of cemented forces at high speed. J Prosthet Dent 2003;89:286-291. ing cavity preparation. J Prosthet Dent 2004;91:436-440.
6. Jorgensen KD. The relationship between retention and crowns to dynamic loading. lnt J Prosthodont 1996;9: 28. Carson J. Rider T, Nash D. A thermographic study of heat 37. Castellani D. La Preparazione dei pilastri per corone in
convergence angle in cemented veneer crowns. Acta 117-139 · distribution during ultra-speed cavity preparation. J metal·ceramica. Bologna: Martina. 1994:207-2o8.
Odontol Scand 1955;13:35-40. 17. Trier AC. Parker MH. Cameron SM. Brousseau JS. Evalu· Dent Res 1979;58:1681-1684. 38. Stein RS, Kuwata M. A dentist and a dental technologist
7- Wilson AH, Chan DC. The relationship between prepara ation of resistance form of dislodged crowns and retain 29. Lauer HC, Kraft E. Rothlauf W. Zwingers l Efects of the analyze current ceramo-metal procedures. Dent Clin
tion convergence and retention of extracoronal retain ers. J Prosthet Dent 1998;80:405-409. temperature of cooling water during high-speed and North Am 1977; 21:729-749.
ers. I Prosthodont 1994;3:74-78. 18. Maxwell AW, Blank LW, Pelleu GB Jr. Efect of crown ultrahigh-speed tooth preparation. I Prosthet Dent 39- Martignoni M, Schonenberger J. Precision Fixed Pros
8. Smith T. Garv 11. Conkin IE. Franks HL Efective taper preparation height on the retention and resistance of 1990:63:407-414. thodontics: Clinical and Laboratorv Aspects. Chicago;
criterion for the full veneer crown preparation in pre
gold castings. Gen Dent 1990;38:20>-202. 30. Laforgia PO, Milano V. Morea C, Desiate A. Temperature Quintessence, 1989.
clinical prosthodontics. I Prosthodont 1999;8:196-200.
19. Parker MH, Calverley MI. Gardner FM. Gunderson RB. change in the pulp chamber during complete crown 40. Magne P, Belser U. Bonded Porcelain Restorations in
9· Noonan IE Jr. Goldfogel MH. Convergence of the axial
New guidelines for preparation taper. 1 Prosthodont preparation. I Prosthet Dent 1991;65:5Ht. the Anterior Dentition: A Biomimetic Approach. Berlin:
walls of full veneer crown preparations in a dental 1993;2:61�6. 31. Galindo OF, Ercoli C. Funkenbusch PO, et al. Tooth Quintessence, 2002:244-247·
school environment. J Prosthet Dent 1991;66:70-708.
20. Woolsey GO. atich JA. The efect of axial grooves on preparation: A study on the efect of diferent variables 41. Kuwata M. Color Atlas of Ceramo-Metal Technology. St
10. Ohm E, Silness J. The convergence angle in teeth pre
the resistance form of cast restorations. 1 Am Dent and a comparison between conventional and channeled Louis: lshiyaku EuroAmenca, 1986.
pared for atiicial crowns. I Oral Rehabil 1978;5:371-375.
Assoc 1978:97:978980. diamond burs. J Prosthodont 2004;13:3-16.
11. Annerstedt . Engstrom U, Hansson . et al. xial wall
21. Proussaefs P, Campagni W, Bernal G, Goodacre C, Kim J.
convergence of full veneer crown preparations. Docu
The efectiveness of auxiliay features on a tooth prepa
mented for dental students and general practitioners.
ration with inadequate resistance form. 1 Prosthet Dent
Acta Odontol Scand 1996:54:10-112.
2004;91:3)-41.
14
107
CHAPTER 3
12. Lempoel Pi. Snoek PA. van1 Hof M. Lemmens Pl. The 2z. Wiskott HW, Nicholls 11. Belser UC. The efect of tooth 32. Ottl P, Lauer HC. Temperature response in the pulpal
REFERENCES
convergence angle of crown preparations with clinically preparation height and diameter on the resistance of chamber during ultrahigh-speed tooth preparation with
1. Kois JC. New paradigms for anterior tooth preparation. satisactorv retention [in Dutch[. Ned Tijdschr Tand· complete crowns to atigue loading. lnt J Prosthodont diamond burs of diferent grit. I Prosthet Dent 1998;
Rationale and technique. Oral Health 1998;88:19-30. heelkd 1993;100:336-338. 1997;10:207-215. 80:12-19.
2. Zanetti AL, engar A. Novelli MD. Lagana DC. Thick· 13. Mou SH. Chai T, Wang )S. Shiau Y. Influence of difer 23. Goodacre CJ. Campagni V, Aquilino SA. Tooth prepa· 33. )ung M, Pantke H . The efect of diamond grinding instru
ness of the remaining enamel after preparation of cin ent convergence angles and tooth preparation heights rations for complete crowns: An art form based on sci ment of diferent grit on dental hard tissue [in Genman].
gulum rest seats on maxillay canines. I Prosthet Dent on the internal adaptation of Cerec crowns. J Prosthet entiic principles. I Prosthet Dent 2001;85:363-376. Dtsch Stomatal 1991;41:32>-322.
1998;8o:31-322. Dent 2002;87=24&-255· 24. Kimmel K. Veahren und Probleme der oralmedizinischen 34· Siegel SC, Von Fraunhofer JA. Cutting eiciency of three
3· Mclean JW. The Science and M of Dental Ceramics. 14. Dodge W. Weed RM. Baez RJ. Buchanan RN. The efect Prlparationstechnik. Quintessenz 2001;52:873-883. diamond bur grit sizes. J Am Dent Assoc 200;131:
Chicago: Quintessence. 1979. of convergence angle on retention and resistance form. 25. Glossav of Prosthodontic Tenms. I Prosthet Dent 2005; 1706-1710.
4. Gargiulo AW. Wentz FM. Orban 81. Dimensions and rela· Quintessence lnt 1985;16:191-194. 94:192. 35· von Fraunhofer )A. Siegel SC. Feldman S. Handpiece
tion of the dentogingival junction in humans. J Peri 15. Shillingburg HT. Hobo S. Whitsett LD. Jacobi R, Brackett 26. Siegel SC, von Fraunhofer JA. Dental cutting with dia· coolant Row rates and dental cutting. Oper Dent 2000:
odontal 1961;32:261-267. SE. Fundamentals of Fixed Prosthodontics, ed 3· Chi· mond burs: Heavy·handed or light-touch? I Prosthodont 25:544-548.
5· Ingber JS, Rose LF, Coslet JG. The "biologic width"-A cago: Quintessence. 1997. 1999:8:39· 36. Ozturk B, Usumez A. Ozturk AN, Ozer . In vitro assess
concept in periodontics and restorative dentistry. Alpha 16. Wiskott HW. Nicholls II, Belser UC. The relationship 27. Elias K, Am is A. Setchell OJ. The magnitude of cutting ment of temperature change in the pulp chamber dur·
Omegan 1977;70:62�5. between abutment taper and resistance of cemented forces at high speed. J Prosthet Dent 2003;89:286-291. ing cavity preparation. J Prosthet Dent 2004;91:436-440.
6. Jorgensen KD. The relationship between retention and crowns to dynamic loading. lnt J Prosthodont 1996;9: 28. Carson J. Rider T, Nash D. A thermographic study of heat 37. Castellani D. La Preparazione dei pilastri per corone in
convergence angle in cemented veneer crowns. Acta 117-139 · distribution during ultra-speed cavity preparation. J metal·ceramica. Bologna: Martina. 1994:207-2o8.
Odontol Scand 1955;13:35-40. 17. Trier AC. Parker MH. Cameron SM. Brousseau JS. Evalu· Dent Res 1979;58:1681-1684. 38. Stein RS, Kuwata M. A dentist and a dental technologist
7- Wilson AH, Chan DC. The relationship between prepara ation of resistance form of dislodged crowns and retain 29. Lauer HC, Kraft E. Rothlauf W. Zwingers l Efects of the analyze current ceramo-metal procedures. Dent Clin
tion convergence and retention of extracoronal retain ers. J Prosthet Dent 1998;80:405-409. temperature of cooling water during high-speed and North Am 1977; 21:729-749.
ers. I Prosthodont 1994;3:74-78. 18. Maxwell AW, Blank LW, Pelleu GB Jr. Efect of crown ultrahigh-speed tooth preparation. I Prosthet Dent 39- Martignoni M, Schonenberger J. Precision Fixed Pros
8. Smith T. Garv 11. Conkin IE. Franks HL Efective taper preparation height on the retention and resistance of 1990:63:407-414. thodontics: Clinical and Laboratorv Aspects. Chicago;
criterion for the full veneer crown preparation in pre
gold castings. Gen Dent 1990;38:20>-202. 30. Laforgia PO, Milano V. Morea C, Desiate A. Temperature Quintessence, 1989.
clinical prosthodontics. I Prosthodont 1999;8:196-200.
19. Parker MH, Calverley MI. Gardner FM. Gunderson RB. change in the pulp chamber during complete crown 40. Magne P, Belser U. Bonded Porcelain Restorations in
9· Noonan IE Jr. Goldfogel MH. Convergence of the axial
New guidelines for preparation taper. 1 Prosthodont preparation. I Prosthet Dent 1991;65:5Ht. the Anterior Dentition: A Biomimetic Approach. Berlin:
walls of full veneer crown preparations in a dental 1993;2:61�6. 31. Galindo OF, Ercoli C. Funkenbusch PO, et al. Tooth Quintessence, 2002:244-247·
school environment. J Prosthet Dent 1991;66:70-708.
20. Woolsey GO. atich JA. The efect of axial grooves on preparation: A study on the efect of diferent variables 41. Kuwata M. Color Atlas of Ceramo-Metal Technology. St
10. Ohm E, Silness J. The convergence angle in teeth pre
the resistance form of cast restorations. 1 Am Dent and a comparison between conventional and channeled Louis: lshiyaku EuroAmenca, 1986.
pared for atiicial crowns. I Oral Rehabil 1978;5:371-375.
Assoc 1978:97:978980. diamond burs. J Prosthodont 2004;13:3-16.
11. Annerstedt . Engstrom U, Hansson . et al. xial wall
21. Proussaefs P, Campagni W, Bernal G, Goodacre C, Kim J.
convergence of full veneer crown preparations. Docu
The efectiveness of auxiliay features on a tooth prepa
mented for dental students and general practitioners.
ration with inadequate resistance form. 1 Prosthet Dent
Acta Odontol Scand 1996:54:10-112.
2004;91:3)-41.
14
107
C H A P T E R 4
F INISH L INE DESIGNS F OR C OM PLETE

CROWN PRE PARATIONS
A
ccording to Castellani,' the finish line is addition to the restorative materials, namely the
defined as the border between the intact por anatomy and tooth position; the number of teeth
tion of the tooth and the most apical point of involved; the skill, precision. and experience of the
the preparation. The design of the finish line is critical operator; and the practicality and convenience of the
in preparing complete crowns; it must be well defined. design (Table 4-1). These criteria force the clinician to TABLE 4-1 Comparison of restorative fi nish lines and their effects on restoration margin
regular, and, above all. well positioned. All of these make diicult and complicated treatment choices that
properties are heavily inluenced by the accessibility, are often case specific and require nonroutine and Level of Restoration Marginal
or depth, of the inish line (igs 4-1 and 4-2). unfamiliar procedures.l·• Type d i ficulty Esthetics margin stress Indications or contraindications
There are numerous types of finish lines dis
Aea inish lines
cussed in the literature, and their use in clinical prac
Indicated for fixed restorations with
tice depends on dental school curricula' and current CHARACTERISTICS O F T H E Feather edge Easy Poor Metal collar Very high
advanced peri-odontal disease;
trends, as well as the kinds of materials used in the VARIOUS F I N ISH L I N ES Easy Poor Metal collar Very high
Knife edge intraoperative dental preparation
restoration. In practical terms. the key factors influ
encing the design are the restorative material (eg, The classification of finish lines involves an impor Complex linear inish lines
metal-ceramic, collarless metal-ceramic, all-ceramic). tant distinction between area and linear finish lines Indicated for multiple connected restorations
Beveled shoulder Diicult Poor Metal collar Very high
the type of connection, and the prosthetic treatment (Figs 4-3 and 4-4). both of which have various con·
Beveled chamfer Dificult Poor Metal collar Vey high Indicated for multiple connected restorations
plan. It is now common for manufacturers to recom figurations. Area finish lines are either feather edged
mend a certai n type of finish line for materials with or knife edged. Linear finish lines are either complex
Simple inish lines
speciic characteristics. or simple and have either a shoulder or a chamfer.
so-degree Easy Moderate Metal collar Moderate Indicated for multiple connected restorations
The complexity of biomechanics requires advanced An area finish line does not clearly delineate the
shoulder or micromargin
techniques, which also must be carefully considered end of the prepared area from the intact portion of
Classic chamfer Easy Moderate Metal collar Minimal Permits a good lit i n cases with
when planning the restoration. The selection of a fin the tooth. These finish lines are oten erroneously
or micromargin buccolingual unevenness; m u ltiple
ish line. therefore, depends on several actors in confused with nonpreparation of a tooth and are . connected restorations
Rounded shoulder Difficult Excellent May use all Minimal Not to be used for multiple connected
Rg 4-1 The finish line of the prep ara ti on must be regular. linear. and properly positioned. Preparations for both complete short chamfer materials restorations
crowns or _inlays depend on the mobohty of the f1nish line.
90-degee Dificult Excellent May use all Moderate Not to be used for multiple connected
Rg 4-2 finish tine on a stone cast for a gold inlay restoration. This finish line. with an external bevel· a support plane · and an
Internal bevel. guarantees the long-term success of the restoration. shoulder materials restorations
Modified chamfer Easy Excellent Optimal lit Minimal Permits a good fit in cases of
with all buccolingual unevenness; multiple
materials connected restorations
11
C H A P T E R 4
F INISH L INE DESIGNS F OR C OM PLETE

CROWN PRE PARATIONS
A
ccording to Castellani,' the finish line is addition to the restorative materials, namely the
defined as the border between the intact por anatomy and tooth position; the number of teeth
tion of the tooth and the most apical point of involved; the skill, precision. and experience of the
the preparation. The design of the finish line is critical operator; and the practicality and convenience of the
in preparing complete crowns; it must be well defined. design (Table 4-1). These criteria force the clinician to TABLE 4-1 Comparison of restorative fi nish lines and their effects on restoration margin
regular, and, above all. well positioned. All of these make diicult and complicated treatment choices that
properties are heavily inluenced by the accessibility, are often case specific and require nonroutine and Level of Restoration Marginal
or depth, of the inish line (igs 4-1 and 4-2). unfamiliar procedures.l·• Type d i ficulty Esthetics margin stress Indications or contraindications
There are numerous types of finish lines dis
Aea inish lines
cussed in the literature, and their use in clinical prac
Indicated for fixed restorations with
tice depends on dental school curricula' and current CHARACTERISTICS O F T H E Feather edge Easy Poor Metal collar Very high
advanced peri-odontal disease;
trends, as well as the kinds of materials used in the VARIOUS F I N ISH L I N ES Easy Poor Metal collar Very high
Knife edge intraoperative dental preparation
restoration. In practical terms. the key factors influ
encing the design are the restorative material (eg, The classification of finish lines involves an impor Complex linear inish lines
metal-ceramic, collarless metal-ceramic, all-ceramic). tant distinction between area and linear finish lines Indicated for multiple connected restorations
Beveled shoulder Diicult Poor Metal collar Very high
the type of connection, and the prosthetic treatment (Figs 4-3 and 4-4). both of which have various con·
Beveled chamfer Dificult Poor Metal collar Vey high Indicated for multiple connected restorations
plan. It is now common for manufacturers to recom figurations. Area finish lines are either feather edged
mend a certai n type of finish line for materials with or knife edged. Linear finish lines are either complex
Simple inish lines
speciic characteristics. or simple and have either a shoulder or a chamfer.
so-degree Easy Moderate Metal collar Moderate Indicated for multiple connected restorations
The complexity of biomechanics requires advanced An area finish line does not clearly delineate the
shoulder or micromargin
techniques, which also must be carefully considered end of the prepared area from the intact portion of
Classic chamfer Easy Moderate Metal collar Minimal Permits a good lit i n cases with
when planning the restoration. The selection of a fin the tooth. These finish lines are oten erroneously
or micromargin buccolingual unevenness; m u ltiple
ish line. therefore, depends on several actors in confused with nonpreparation of a tooth and are . connected restorations
Rounded shoulder Difficult Excellent May use all Minimal Not to be used for multiple connected
Rg 4-1 The finish line of the prep ara ti on must be regular. linear. and properly positioned. Preparations for both complete short chamfer materials restorations
crowns or _inlays depend on the mobohty of the f1nish line.
90-degee Dificult Excellent May use all Moderate Not to be used for multiple connected
Rg 4-2 finish tine on a stone cast for a gold inlay restoration. This finish line. with an external bevel· a support plane · and an
Internal bevel. guarantees the long-term success of the restoration. shoulder materials restorations
Modified chamfer Easy Excellent Optimal lit Minimal Permits a good fit in cases of
with all buccolingual unevenness; multiple
materials connected restorations
11
CHAPtER 4
Fin1sh Line Designs for Complete Crown Preparations
A R E A A N D L I N E A R F I N ISH L I N ES
Figs 4-3 and 4-4 Two principal types of f1nish line, linear I Fig 4-1 and area I Fig 4-4). Tooth preparation with a linear
finish line ends on a distinct line for its entire circumference. An area finish adapts the tooth preparation to the entire
surface rather than to an exact li ne .
..commonly found under old fixed dental restorations. subject to distortion and tension.s However, area in
Although feather and knife edges are valid finish ish lines are sometimes the best clinical solution dur
lines that require the removal of dental tissue and ing the surgical stage for cases of advanced peri
the definition of form and volume, they are used odontal disease that require a fixed dental prosthe
less frequently in current clinical practice. It is the sis.6 Area inish lines may also be useful for con
authors' opinion, however, that a mediocre area fin necting several restorative crowns together to stabi
ish line is preferable to a mediocre linear inish line. lize dental movement in the presence of signiicant
With an area finish line (Fig 4-5), the marginal seal ly reduced periodontal support.7 In �uch a situation,
will be more sure, whereas an inadequate linear fin it would be impossible to splint many crowns pre
ish line inevitably produces a significant gap at the pared, for example, with a shoulder design because
restoration margin (Fig 4-6). of the lack of space between the tooth abutments
The main problem with area finish lines is that, Fig 4-5 1ncorrect area finish line. The obvious convexity of this preparation in profile creates an undercut. which presents a drawback
during the laboratory work and because of a prob
for both adaptation and insertion of the prosthesis.
given the preparation space and the thickness of re lem with the angles and planes. Although area finish Fig4-6 Evident gap from the matching of an inadequate linear finish line to an ill-fitting metal margin. The same error for an area fin
storative materials, they are suitable only for crowns lines yield good marginal adaptation, the authors ish line is more acceptable because the seal covers an entire area of the surface instead of just a line.
with metal collars. furthermore, the thickness of the Figs 4-7 and 4-8 Clinical case of a patient with advanced periodontal disease and considerable buccal flaring of the teeth. The teeth
prefer, even in such a case, to perform seconday
were realigned through orthodontic and periodontal treatment and required a fixed prosthesis. The treatment aimed to cause u lit
restorations at the margin does not meet minimum welds once the margins are closed individually on tle damage to the pulp as possible. Ceramic crowns were made individually and united using secondary welds i n three sections
recommended values for laboratory procedures, equipped with interlock devices. The area for the secondary weld was prepared by the dental technician along with the waxing of the
chamfer, modified chamfer, or other linear finish lines framework and ceramic coating of the connections. The welding was completed only after the ceramic was applied.
which may result in a margin that is weak and thus (Figs 4-7 and 4-8).8.9 .
110 1t1
CHAPtER 4
Fin1sh Line Designs for Complete Crown Preparations
A R E A A N D L I N E A R F I N ISH L I N ES
Figs 4-3 and 4-4 Two principal types of f1nish line, linear I Fig 4-1 and area I Fig 4-4). Tooth preparation with a linear
finish line ends on a distinct line for its entire circumference. An area finish adapts the tooth preparation to the entire
surface rather than to an exact li ne .
..commonly found under old fixed dental restorations. subject to distortion and tension.s However, area in
Although feather and knife edges are valid finish ish lines are sometimes the best clinical solution dur
lines that require the removal of dental tissue and ing the surgical stage for cases of advanced peri
the definition of form and volume, they are used odontal disease that require a fixed dental prosthe
less frequently in current clinical practice. It is the sis.6 Area inish lines may also be useful for con
authors' opinion, however, that a mediocre area fin necting several restorative crowns together to stabi
ish line is preferable to a mediocre linear inish line. lize dental movement in the presence of signiicant
With an area finish line (Fig 4-5), the marginal seal ly reduced periodontal support.7 In �uch a situation,
will be more sure, whereas an inadequate linear fin it would be impossible to splint many crowns pre
ish line inevitably produces a significant gap at the pared, for example, with a shoulder design because
restoration margin (Fig 4-6). of the lack of space between the tooth abutments
The main problem with area finish lines is that, Fig 4-5 1ncorrect area finish line. The obvious convexity of this preparation in profile creates an undercut. which presents a drawback
during the laboratory work and because of a prob
for both adaptation and insertion of the prosthesis.
given the preparation space and the thickness of re lem with the angles and planes. Although area finish Fig4-6 Evident gap from the matching of an inadequate linear finish line to an ill-fitting metal margin. The same error for an area fin
storative materials, they are suitable only for crowns lines yield good marginal adaptation, the authors ish line is more acceptable because the seal covers an entire area of the surface instead of just a line.
with metal collars. furthermore, the thickness of the Figs 4-7 and 4-8 Clinical case of a patient with advanced periodontal disease and considerable buccal flaring of the teeth. The teeth
prefer, even in such a case, to perform seconday
were realigned through orthodontic and periodontal treatment and required a fixed prosthesis. The treatment aimed to cause u lit
restorations at the margin does not meet minimum welds once the margins are closed individually on tle damage to the pulp as possible. Ceramic crowns were made individually and united using secondary welds i n three sections
recommended values for laboratory procedures, equipped with interlock devices. The area for the secondary weld was prepared by the dental technician along with the waxing of the
chamfer, modified chamfer, or other linear finish lines framework and ceramic coating of the connections. The welding was completed only after the ceramic was applied.
which may result in a margin that is weak and thus (Figs 4-7 and 4-8).8.9 .
110 1t1
CHAPTER 4
Finish Line Designs for Complete Crown Preparations
� occlusal force. The authors avoid this type of finish

Area finish lines
line when possible, preferring, even in cases of ad
Area finish lines (Fig 4-9 to 4-11), both feather- and vanced periodontal disease, finish lines that include
knife-edged, offer several advantages clinically and in a minimal angle to properly support the restorative
the laboratory. The angle between the axial wall and materials.
the radicular wall is near or slightly less than 180

degrees. Clinicians distinguish between a feather edge,
Linear finish lines
with an angle of approximately 180 degrees, and a
knife edge, with an angle slightly less than 180 The following distinctions can be made between
degrees. Area finish lines are relatively easy to com preparations with a linear finish lines. Complex linear
plete because the operator does not have to focus on finish lines have a beveled shoulder or a beveled
creating a distinct linear finish line, thus reducing the chamfer. Simple linear finish lines have a so- or 135-
clinician's stress and fatigue. However, circular and degree shoulder, a classic chamfer, a rounded shoul
rotational movements and the use of small-diameter der, a 90-degree shoulder, or a modified chamfer.
burs should be avoided during the preparation to
prevent irregular surfaces, conical tooth preparations, Complex, Beveled chamfer and beveled shoulder
or overheating of the pulp. Although complex finish lines require the formation of FIG 4-9 FIG 4-10 FIG 4-1 1
The area inish line is indicated for fixed dental an angle, they are addressed first because their bevel
restorations i n periodontal cases, for intraoperative is, in some ways, similar to the area finish lines. The Fig 4- g Cross section o f a tooth preparation with a n area finish line. The near absence o f a definitive line permits a strong seal
dental preparation, and for multiple fixed restora beveled chamfer inish line is often cited i n the liter at the restoration margin.
tions. It is the authors' belief that because of modern ature but rarely used in clinical practice. Given its Fig 4-10 Area finish line completed with a flame-shaped bur. I n the authors' view. the shape of this bur i s wrong for creating
an area finish line.
implant technology, full-mouth fixed restorations similarity to the beveled shoulder design, it will be Fig 4-11 Use of a large-diameter conical cham fe r b u r i s generally recommended for area finish lines.
should be avoided, and instead connecting and link included in the analysis of the beveled shoulder.
ing should take place for partial segments. This has The beveled shoulder finish line is complex be
clear advantages for precision in all operative stages, cause the design is obtained through the intersection � years of experience. This finish line reduces the gina I adaptation. Bevels with angles greater than 70
not least in the cementation stage. of two lines, but this finish line provides no clear amount of exposed cement. which would seem to degrees require edges so thin that the stability can
Area inish lines also have several disadvantages. advantage over less dificult designs (Fig 4-12). The indicate a better marginal seal."·" On the other not be checked during the working stages. and any
Excellent esthetics are unlikely to result from an area beveled shoulder can be accomplished in two ways. hand, a finish line with an internal angle close to 90 openings or distortions i n the restorative margins
inish line because the thin area of support at the fin In one case, the entire preparation is executed using degrees could impede the normal cement flow, cannot be corrected in subsequent stages. Moreover,
ish line is insuicient for ceramic material, with or a 90-degree bur, and, after the shoulder is made, the especially under conditions of abnormal fluidity,'J such edges lose their shape during laboratory pro
without metal margins. Therefore, a metallic border of exterior finish line is rounded off until the desired and result in occlusal lifting. cedures or because of occlusal force.8
significant height is needed, making the cervical area bevel is formed (Figs 4-13 and 4-14). The other tech One possible advantage of the bevel is that it Another point made in the literature' in fa vor of
less esthetic. Horizontally, the space is too limited to nique involves first designing the finish line with a could be used i n conjunction with the shoulder to beveled finish lines is the possibility of burnishing
ofer proper support for any restorative material long chamfer (this will later constitute the bevel), and combine the benefits of a greater support area of the margin a fter cementation by using rotating burs
because of the minimal angle that is created with the then using a 90-degree bur to execute the shoulder the shoulder and the ferrule efect of the bevel. at low speed. The authors believe that, from a prac
axial wall. The stress that is distributed to this finish in the internal portion of the chamfer (Fig 4-15). According to Mclean and Wilson,'4 however, the tical standpoint, this is impossible because of the
line exceeds that of other types of finish lines'0 and In analyzing the advantages of this finish line, the angle of the bevel must be at least 45 degrees to subgingival extension of the restoration margins and
results in distortion of the thin metal at the margin of authors find it impossible to confine their discussion obtain the retention and ferrule efects. but only the likelihood of damaging the metallic margins. ..
the restoration during iring or when subjected to to theoretical concepts without drawing upon their .. bevels with more than 70 degrees improve the mar-
112
113
CHAPTER 4
� occlusal force. The authors avoid this type of finish

Area finish lines
line when possible, preferring, even in cases of ad
Area finish lines (Fig 4-9 to 4-11), both feather- and vanced periodontal disease, finish lines that include
knife-edged, offer several advantages clinically and in a minimal angle to properly support the restorative
the laboratory. The angle between the axial wall and materials.
the radicular wall is near or slightly less than 180

degrees. Clinicians distinguish between a feather edge,
Linear finish lines
with an angle of approximately 180 degrees, and a
knife edge, with an angle slightly less than 180 The following distinctions can be made between
degrees. Area finish lines are relatively easy to com preparations with a linear finish lines. Complex linear
plete because the operator does not have to focus on finish lines have a beveled shoulder or a beveled
creating a distinct linear finish line, thus reducing the chamfer. Simple linear finish lines have a so- or 135-
clinician's stress and fatigue. However, circular and degree shoulder, a classic chamfer, a rounded shoul
rotational movements and the use of small-diameter der, a 90-degree shoulder, or a modified chamfer.
burs should be avoided during the preparation to
prevent irregular surfaces, conical tooth preparations, Complex, Beveled chamfer and beveled shoulder
or overheating of the pulp. Although complex finish lines require the formation of FIG 4-9 FIG 4-10 FIG 4-1 1
The area inish line is indicated for fixed dental an angle, they are addressed first because their bevel
restorations i n periodontal cases, for intraoperative is, in some ways, similar to the area finish lines. The Fig 4- g Cross section o f a tooth preparation with a n area finish line. The near absence o f a definitive line permits a strong seal
dental preparation, and for multiple fixed restora beveled chamfer inish line is often cited i n the liter at the restoration margin.
tions. It is the authors' belief that because of modern ature but rarely used in clinical practice. Given its Fig 4-10 Area finish line completed with a flame-shaped bur. I n the authors' view. the shape of this bur i s wrong for creating
an area finish line.
implant technology, full-mouth fixed restorations similarity to the beveled shoulder design, it will be Fig 4-11 Use of a large-diameter conical cham fe r b u r i s generally recommended for area finish lines.
should be avoided, and instead connecting and link included in the analysis of the beveled shoulder.
ing should take place for partial segments. This has The beveled shoulder finish line is complex be
clear advantages for precision in all operative stages, cause the design is obtained through the intersection � years of experience. This finish line reduces the gina I adaptation. Bevels with angles greater than 70
not least in the cementation stage. of two lines, but this finish line provides no clear amount of exposed cement. which would seem to degrees require edges so thin that the stability can
Area inish lines also have several disadvantages. advantage over less dificult designs (Fig 4-12). The indicate a better marginal seal."·" On the other not be checked during the working stages. and any
Excellent esthetics are unlikely to result from an area beveled shoulder can be accomplished in two ways. hand, a finish line with an internal angle close to 90 openings or distortions i n the restorative margins
inish line because the thin area of support at the fin In one case, the entire preparation is executed using degrees could impede the normal cement flow, cannot be corrected in subsequent stages. Moreover,
ish line is insuicient for ceramic material, with or a 90-degree bur, and, after the shoulder is made, the especially under conditions of abnormal fluidity,'J such edges lose their shape during laboratory pro
without metal margins. Therefore, a metallic border of exterior finish line is rounded off until the desired and result in occlusal lifting. cedures or because of occlusal force.8
significant height is needed, making the cervical area bevel is formed (Figs 4-13 and 4-14). The other tech One possible advantage of the bevel is that it Another point made in the literature' in fa vor of
less esthetic. Horizontally, the space is too limited to nique involves first designing the finish line with a could be used i n conjunction with the shoulder to beveled finish lines is the possibility of burnishing
ofer proper support for any restorative material long chamfer (this will later constitute the bevel), and combine the benefits of a greater support area of the margin a fter cementation by using rotating burs
because of the minimal angle that is created with the then using a 90-degree bur to execute the shoulder the shoulder and the ferrule efect of the bevel. at low speed. The authors believe that, from a prac
axial wall. The stress that is distributed to this finish in the internal portion of the chamfer (Fig 4-15). According to Mclean and Wilson,'4 however, the tical standpoint, this is impossible because of the
line exceeds that of other types of finish lines'0 and In analyzing the advantages of this finish line, the angle of the bevel must be at least 45 degrees to subgingival extension of the restoration margins and
results in distortion of the thin metal at the margin of authors find it impossible to confine their discussion obtain the retention and ferrule efects. but only the likelihood of damaging the metallic margins. ..
the restoration during iring or when subjected to to theoretical concepts without drawing upon their .. bevels with more than 70 degrees improve the mar-
112
113
CH�PTER 4
. tal tissues and enables the clinician to prepare a
\
Among the shortcomings of this complex design
is the difficulty of adequately establishing the finish subgingival margin without retracting the gingiva. For
line, realizing it equally on all sides of the tooth, cases in which a retraction cord is not used in the
·.
and taking impressions of the bevel. The clinician is initial stage of preparation, this technique may be
required to use a high degree of concentration to used to position an intrasulcular restoration margin.
precisely define the position of two lines and the Because more than one third of the longitudinal
exact spacing between them. axis of the prepared tooth consists of the finish line
The design of the most exterior portion of the fin· area, this preparation design considerably reduces
ish line provides insuficient support for all-ceramic the surface retention for the crown. The area of the
material. To provide suficient resistance against the preparation that usually provides the greatest sup
flexure forces that are generated at the margin, it is port (that is, the area with the largest diameter and
necessary to use a metal edge to seal the margin, hence the greatest surface area) is very conical in
which provides less than optimal esthetics. More this design because the finish line develops on a
over, the thin metal edges used with bevels of slant (Figs 4-17 and 4-18).21 The conical shape makes
angles greater than 70 degrees have a tendency to this technique unsuitable for teeth of reduced height
lose their shape during laboratory preparation or but advisable for splinted prostheses connecting
because of the vey high marginal stress during multiple teeth.
occlusion.8 In the authors' view, this finish line represents an
The authors believe that this type of complex fin evolutionary step, in esthetic terms, from area finish
ish line is now obsolete because it is difficult to lines. Nonetheless, the so- and 135-degree shoul
master, requires considerable dexterity and concen ders are outdated because they do not provide a
tration and does not provide the benefits it was suficient zone of support for newer esthetic restora
designed to furnish.'S-18 Moreover, most patients con tion materials with ceramic margins (Fig 4-19).
sider the visible metal margin unesthetic. For this design, the best esthetic results can be
achieved with the ceramic micromargin, a restora
Simple: 50- and 1 35-degree shoulder tion margin of metal that is coated in an opaque
The 50- and 135-degree shoulders are simple finish material and then layered in ceramic. This complex
lines. They are based on the plane of reference used technique requires the use of a microscope in the
to measure the size of the angle, either the hori laboratoy and a dental technician who has experi
zontal or longitudinal axis of the toothl4-t9 (Fig 4-16). ence working at high magnification. All three types
The popularity of this type of finish line during the of restorative materials are used in this margin, pro
198os and 1990s is largely due to the studies con viding the advantages of a metal closure and con
ducted by Kuwatas and by Martignoni and Shonen ventional cementation along with the esthetics of a
ig 4-12 Cross section of a tooth prepared with complex beveled shoulder finish line.
berger20 as well as its intrinsic simplicity. ceramic margin. The greatest problem is how to fit
Fig 4-13 Thin flame-shaped bur. 2.5 m m long. used to prepare the finish line without interfering with the walls of the tooth preparation itself
Visibility while working with the bur is excellent. the three materials in such a small space; it is or with the adjacent tooth.
The clinician may immediately determine the final almost impossible without resorting to horizontal Fig 4-14 Small-diameter football-shaped tungsten carbide bur used to make a shorter. concave bevel.
angle and shape of the preparation by using half the Fig 4-15 Beveled shoulder finish line may be completed even after preparation of a long chamfer by shifting the shoulder internally with 1 90-
contours, although these are of limited extension
degree bur.
diameter of the instrument, held vetically. The bur's and are clinically insignificant if reduced correctly. -
pointed shape causes minimal damage to periodon-
114
115
CH�PTER 4
. tal tissues and enables the clinician to prepare a
\
Among the shortcomings of this complex design
is the difficulty of adequately establishing the finish subgingival margin without retracting the gingiva. For
line, realizing it equally on all sides of the tooth, cases in which a retraction cord is not used in the
·.
and taking impressions of the bevel. The clinician is initial stage of preparation, this technique may be
required to use a high degree of concentration to used to position an intrasulcular restoration margin.
precisely define the position of two lines and the Because more than one third of the longitudinal
exact spacing between them. axis of the prepared tooth consists of the finish line
The design of the most exterior portion of the fin· area, this preparation design considerably reduces
ish line provides insuficient support for all-ceramic the surface retention for the crown. The area of the
material. To provide suficient resistance against the preparation that usually provides the greatest sup
flexure forces that are generated at the margin, it is port (that is, the area with the largest diameter and
necessary to use a metal edge to seal the margin, hence the greatest surface area) is very conical in
which provides less than optimal esthetics. More this design because the finish line develops on a
over, the thin metal edges used with bevels of slant (Figs 4-17 and 4-18).21 The conical shape makes
angles greater than 70 degrees have a tendency to this technique unsuitable for teeth of reduced height
lose their shape during laboratory preparation or but advisable for splinted prostheses connecting
because of the vey high marginal stress during multiple teeth.
occlusion.8 In the authors' view, this finish line represents an
The authors believe that this type of complex fin evolutionary step, in esthetic terms, from area finish
ish line is now obsolete because it is difficult to lines. Nonetheless, the so- and 135-degree shoul
master, requires considerable dexterity and concen ders are outdated because they do not provide a
tration and does not provide the benefits it was suficient zone of support for newer esthetic restora
designed to furnish.'S-18 Moreover, most patients con tion materials with ceramic margins (Fig 4-19).
sider the visible metal margin unesthetic. For this design, the best esthetic results can be
achieved with the ceramic micromargin, a restora
Simple: 50- and 1 35-degree shoulder tion margin of metal that is coated in an opaque
The 50- and 135-degree shoulders are simple finish material and then layered in ceramic. This complex
lines. They are based on the plane of reference used technique requires the use of a microscope in the
to measure the size of the angle, either the hori laboratoy and a dental technician who has experi
zontal or longitudinal axis of the toothl4-t9 (Fig 4-16). ence working at high magnification. All three types
The popularity of this type of finish line during the of restorative materials are used in this margin, pro
198os and 1990s is largely due to the studies con viding the advantages of a metal closure and con
ducted by Kuwatas and by Martignoni and Shonen ventional cementation along with the esthetics of a
ig 4-12 Cross section of a tooth prepared with complex beveled shoulder finish line.
berger20 as well as its intrinsic simplicity. ceramic margin. The greatest problem is how to fit
Fig 4-13 Thin flame-shaped bur. 2.5 m m long. used to prepare the finish line without interfering with the walls of the tooth preparation itself
Visibility while working with the bur is excellent. the three materials in such a small space; it is or with the adjacent tooth.
The clinician may immediately determine the final almost impossible without resorting to horizontal Fig 4-14 Small-diameter football-shaped tungsten carbide bur used to make a shorter. concave bevel.
angle and shape of the preparation by using half the Fig 4-15 Beveled shoulder finish line may be completed even after preparation of a long chamfer by shifting the shoulder internally with 1 90-
contours, although these are of limited extension
degree bur.
diameter of the instrument, held vetically. The bur's and are clinically insignificant if reduced correctly. -
pointed shape causes minimal damage to periodon-
114
115
CHAPTER 4
shoulders and the differences in the buccal and . Taking an impression of the finish line contours it is decidedly m o re versatile than both and less de
. Simple. Classtc chamfer
palatal levels, which is accentuated in natural teeth, is also difficult. A shoulder finish line with an under· manding of the clinician's effort and time (Fig 4-40).
The classic chamfer is a finish line that generally
exploits the absence of a sharp internal angle and is make it impossible to achieve exact adaptation with lying "horizontal plate" design may stress the im To execute a modified chamfer, the clinician may
defined as long or short, according to the degree of this design. pression material's resistance to tearing when the use half the diameter of the diamond bur to mea
concavity in the preparation (Fig 4-20). This design The popularity of this finish line is driven by impression is removed from the mouth. Therefore, it sure the reduction, keeping the finish line a s close
is easy to execute, in practical clinical terms, and patients' continuing demand for improved esthetics. is more dificult to make a clear impression with an as possible to the center of the bur (Fig 4-41). This
can be adapted to various restoration scenarios The drive for esthetics has resulted in widespread intact tooth structure beyond the finish line, com design may be used for various restorative materi
(Figs 4-21 to 4-23). The classic chamfer is ideal for use of all-ceramic crowns and the popularity of pared with a more vertical or a slanted finish line als, and it leaves the type of margin open to decision
teeth with substantial differences in buccal and lin implant-supported prostheses, which have greatly design. at any stage of treatment, even after the i m p ression
gual levels or multiple connected restorations. The improved the esthetics of restorative solutions for has been made. This finish line is thus u niversally
restoration margins endure reduced stress because the edentulous. For these reasons, especially i n S i m ple: 90-degree shoulder applicable to any type of restoration margin. With
the occlusal force is more evenly distributed over recent years, restorations have become more depen· The last of the common finish lines is the go-degree the proper area of support executed by the clinician,
the entire restoration. The finish line cannot take a dent on adhesives rather than metal structural sup shoulder (Figs 4-33 to 4-3s). Though still discussed, this design can accept all-ceramic crowns, metal
collarless metal-ceramic restoration but works with a ports. Clinicians now use porcelain laminate veneers the 90-degree shoulder finish line has been sup ceramic crowns, collarless metal-ceramic, or metal
metal margin or micromargin. However, the dental or all-ceramic crowns on nonvital teeth reconstruct planted by the rounded shoulder design for practi ceramic crowns with a metallic margin or micromar
technician has difficulty controlling the stability of ed with fiberglass dowels. For larger edentulous cal and ergonomic reasons. Moreover, the diamond gin (Figs 4-42 to 4-44).
the metal, resulting in frequent distortions during areas, small fixed partial dentures are being made at the vey tip of the new bur is the first to be dis The micromargin may be used because clinicians
firing.22 using the collarless technique" or with a structure lodged during the rotating impact, thus impeding have found that a so-degree bur is the least dam
This preparation has many of the same charac of nonmetallic materials. With ample support at the the formation of a sharp angle (Figs 4-36 and 4-37). aging to the periodontal tissues during the defini
teristics as the so-degree finish line, as well as some marginal level, the clinician may use all-ceramic However, this design is still used when the clinical tion of the finish line and permits a restoration at
improvements owing to the concave design. This dif restorations with this finish line. Feldspathic ce crown of a short tooth cannot be surgically length the critical angleS where metal, opaque, and ceram
ference allots more space for the restorative materi ramic crowns impart the most esthetically pleasing ened or orthodontically extruded. In such a case, the ic layers meet. In addition to the esthetic problems
als and improves the esthetics. However, the greater effect, but crowns with an alumina core or pressable 90-degree shoulder is the only finish line that per related to the limited space available for the ceram
lateral or external extension of the rotation of the ceramic crowns ofer better function, especially ater mits maximum surface retention. This finish line is ic, described earlier, the authors believe that an
diamond bur causes slightly more damage to the cementation, combined with long-term resistance to also frequently used for ceramic inlay preparations angle of this size does not have room for adequate
gingival tissue. occlusal force (Figs 4-29 and 4-30). (Figs 4-38 and 4-39). Although clinicians no longer metal material. If the metal is not sufficient, the den
For the clinician, this design is not easy to exe use this design for complete crown restorations, any tal technician will ace problems of instability during
Simple: Short chamfer or rounded shoulder cute. The center of the rounded bur is difficult to clinician doing prosthetic work would be advised to the various firing cycles and a margin design that
Deepening the chamfer by using a more rounded identify, and, because measurment is compromised, become familiar with it and learn how to position cannot absorb the tensions caused by the crystal
point produces a short chamfer or rounded shoulder excessive abrasion along the axial surface can result and finish this well-defined finish line. lattice of the alloy.'4
finish line, which is currently the design most fre in weakened areas that lack support and give an To stabilize the metal during iring for a precise
quently used in US dental schools' (Figs 4-24 to undesirable curl to the finish line (Figs 4-31 and Simple: Modified chamfer adaptation, Massironi et at'S perfected a technique
4-28). The short chamfer finish line is a modern 4-32). This obstacle creates considerable difficulty, The design known as the modied chamfer was known as the counter-chamfer that involves increas
version of the long chamfer, developed to meet de sometimes preventing the dental technician from created to provide adequate space for all kinds of ing the thickness of the metal used for the restora
mands for better esthetics at the expense of some producing a precise prosthesis. Above all, the pres restorations and to leave the decision of the restora tion margin, which is a medium title, 54% gold
functional features. The shot chamfer creates greater ence of a curl creates a fragile area in the margin, tion margin open at every stage of treatment.'l The (BegoStar, Bego), creating a slightly convex shape.
difficulties in connecting several crowns and in using which may break during use and can even lead to modified chamfer finish line is described as a long While this technique works admirably to increase
certain metal alloys. In cases where several prepared secondary caries. .. chamfer combined with a rounded shoulder, though the stability of the metal, it further reduces the ..
teeth are connected, the presence of numerous flat
111
117
CHAPTER 4
shoulders and the differences in the buccal and . Taking an impression of the finish line contours it is decidedly m o re versatile than both and less de
. Simple. Classtc chamfer
palatal levels, which is accentuated in natural teeth, is also difficult. A shoulder finish line with an under· manding of the clinician's effort and time (Fig 4-40).
The classic chamfer is a finish line that generally
exploits the absence of a sharp internal angle and is make it impossible to achieve exact adaptation with lying "horizontal plate" design may stress the im To execute a modified chamfer, the clinician may
defined as long or short, according to the degree of this design. pression material's resistance to tearing when the use half the diameter of the diamond bur to mea
concavity in the preparation (Fig 4-20). This design The popularity of this finish line is driven by impression is removed from the mouth. Therefore, it sure the reduction, keeping the finish line a s close
is easy to execute, in practical clinical terms, and patients' continuing demand for improved esthetics. is more dificult to make a clear impression with an as possible to the center of the bur (Fig 4-41). This
can be adapted to various restoration scenarios The drive for esthetics has resulted in widespread intact tooth structure beyond the finish line, com design may be used for various restorative materi
(Figs 4-21 to 4-23). The classic chamfer is ideal for use of all-ceramic crowns and the popularity of pared with a more vertical or a slanted finish line als, and it leaves the type of margin open to decision
teeth with substantial differences in buccal and lin implant-supported prostheses, which have greatly design. at any stage of treatment, even after the i m p ression
gual levels or multiple connected restorations. The improved the esthetics of restorative solutions for has been made. This finish line is thus u niversally
restoration margins endure reduced stress because the edentulous. For these reasons, especially i n S i m ple: 90-degree shoulder applicable to any type of restoration margin. With
the occlusal force is more evenly distributed over recent years, restorations have become more depen· The last of the common finish lines is the go-degree the proper area of support executed by the clinician,
the entire restoration. The finish line cannot take a dent on adhesives rather than metal structural sup shoulder (Figs 4-33 to 4-3s). Though still discussed, this design can accept all-ceramic crowns, metal
collarless metal-ceramic restoration but works with a ports. Clinicians now use porcelain laminate veneers the 90-degree shoulder finish line has been sup ceramic crowns, collarless metal-ceramic, or metal
metal margin or micromargin. However, the dental or all-ceramic crowns on nonvital teeth reconstruct planted by the rounded shoulder design for practi ceramic crowns with a metallic margin or micromar
technician has difficulty controlling the stability of ed with fiberglass dowels. For larger edentulous cal and ergonomic reasons. Moreover, the diamond gin (Figs 4-42 to 4-44).
the metal, resulting in frequent distortions during areas, small fixed partial dentures are being made at the vey tip of the new bur is the first to be dis The micromargin may be used because clinicians
firing.22 using the collarless technique" or with a structure lodged during the rotating impact, thus impeding have found that a so-degree bur is the least dam
This preparation has many of the same charac of nonmetallic materials. With ample support at the the formation of a sharp angle (Figs 4-36 and 4-37). aging to the periodontal tissues during the defini
teristics as the so-degree finish line, as well as some marginal level, the clinician may use all-ceramic However, this design is still used when the clinical tion of the finish line and permits a restoration at
improvements owing to the concave design. This dif restorations with this finish line. Feldspathic ce crown of a short tooth cannot be surgically length the critical angleS where metal, opaque, and ceram
ference allots more space for the restorative materi ramic crowns impart the most esthetically pleasing ened or orthodontically extruded. In such a case, the ic layers meet. In addition to the esthetic problems
als and improves the esthetics. However, the greater effect, but crowns with an alumina core or pressable 90-degree shoulder is the only finish line that per related to the limited space available for the ceram
lateral or external extension of the rotation of the ceramic crowns ofer better function, especially ater mits maximum surface retention. This finish line is ic, described earlier, the authors believe that an
diamond bur causes slightly more damage to the cementation, combined with long-term resistance to also frequently used for ceramic inlay preparations angle of this size does not have room for adequate
gingival tissue. occlusal force (Figs 4-29 and 4-30). (Figs 4-38 and 4-39). Although clinicians no longer metal material. If the metal is not sufficient, the den
For the clinician, this design is not easy to exe use this design for complete crown restorations, any tal technician will ace problems of instability during
Simple: Short chamfer or rounded shoulder cute. The center of the rounded bur is difficult to clinician doing prosthetic work would be advised to the various firing cycles and a margin design that
Deepening the chamfer by using a more rounded identify, and, because measurment is compromised, become familiar with it and learn how to position cannot absorb the tensions caused by the crystal
point produces a short chamfer or rounded shoulder excessive abrasion along the axial surface can result and finish this well-defined finish line. lattice of the alloy.'4
finish line, which is currently the design most fre in weakened areas that lack support and give an To stabilize the metal during iring for a precise
quently used in US dental schools' (Figs 4-24 to undesirable curl to the finish line (Figs 4-31 and Simple: Modified chamfer adaptation, Massironi et at'S perfected a technique
4-28). The short chamfer finish line is a modern 4-32). This obstacle creates considerable difficulty, The design known as the modied chamfer was known as the counter-chamfer that involves increas
version of the long chamfer, developed to meet de sometimes preventing the dental technician from created to provide adequate space for all kinds of ing the thickness of the metal used for the restora
mands for better esthetics at the expense of some producing a precise prosthesis. Above all, the pres restorations and to leave the decision of the restora tion margin, which is a medium title, 54% gold
functional features. The shot chamfer creates greater ence of a curl creates a fragile area in the margin, tion margin open at every stage of treatment.'l The (BegoStar, Bego), creating a slightly convex shape.
difficulties in connecting several crowns and in using which may break during use and can even lead to modified chamfer finish line is described as a long While this technique works admirably to increase
certain metal alloys. In cases where several prepared secondary caries. .. chamfer combined with a rounded shoulder, though the stability of the metal, it further reduces the ..
teeth are connected, the presence of numerous flat
111
117
CHAPTER 4
TOOTH
METHACRY
LATE
RESIN
Fig 4-16 Cross section of a 50-degree shoulder. Fig 4-20 Cross section showing the slight concavity of the classic long chamfer design. which permits better esthetics than the 50-degree
shoulder design.
Fig 4-17 Coarse-grit bur used to create a 50-degree shoulder on an extracted tooth.
Figs 4-21 and 4-22 Coarse- and fine-grit round burs. used for preliminary preparation and finishing, respectively. of the classic chamfer.
Fig 4-18 Fine-grit bur used to create a 50-degree shoulder on an extracted tooth. This design exhibits low retention. The use of collarless
metal-ceramic restorative materials is impossible. Fig 4-23 Cross section of a metal-ceramic restoration with a long chamfer design.
Fig 4-1 g A cross section of a 50-degree shoulder photographed through the microscope under polarized light. The preparation records the
negative image of the bur used to abrade the tooth.
118 119
CHAPTER 4
TOOTH
METHACRY
LATE
RESIN
Fig 4-16 Cross section of a 50-degree shoulder. Fig 4-20 Cross section showing the slight concavity of the classic long chamfer design. which permits better esthetics than the 50-degree
shoulder design.
Fig 4-17 Coarse-grit bur used to create a 50-degree shoulder on an extracted tooth.
Figs 4-21 and 4-22 Coarse- and fine-grit round burs. used for preliminary preparation and finishing, respectively. of the classic chamfer.
Fig 4-18 Fine-grit bur used to create a 50-degree shoulder on an extracted tooth. This design exhibits low retention. The use of collarless
metal-ceramic restorative materials is impossible. Fig 4-23 Cross section of a metal-ceramic restoration with a long chamfer design.
Fig 4-1 g A cross section of a 50-degree shoulder photographed through the microscope under polarized light. The preparation records the
negative image of the bur used to abrade the tooth.
118 119
CHAPTER 4
I
Finish Line Designs for Complete Crown Preparations \
Fig 4-24 Rounded burs in coarse and fine grit and in 0.14- and 0.1 6-mm diameters. used for the shoulder design. Figs 4-19 and 4-30 Frontal and sagittal views of a prepared central incisor. The spatial proportions of the tooth are maintained by removing an
Figs 4-15 o. 4-18 Different diameters are � sed for the interproximal spaces and for the palatal and buccal areas. and different grits are used adequate amount of tooth from the correct areas. The different positions of the buccal and palatal shoulders result from the natural differ
. ence in levels.
for prellmmary reductiOn and for fmosh1ng. The short chamfer or rounded shoulder finish line produces the ideal support for feldspathic
ceramic and all-ceramic restorations. Figs 4-31 and 4-31 Excessive longitudinal abrasion of the bur and the loss of a measurement reference can result i n a curled finish line design
that can not be adequately supported and is likely lo break under occlusal force. lt is also difficult for a dental technician lo fabricate a
restoration for this type of incorrect finish line preparation.
10 121
CHAPTER 4
I
Finish Line Designs for Complete Crown Preparations \
Fig 4-24 Rounded burs in coarse and fine grit and in 0.14- and 0.1 6-mm diameters. used for the shoulder design. Figs 4-19 and 4-30 Frontal and sagittal views of a prepared central incisor. The spatial proportions of the tooth are maintained by removing an
Figs 4-15 o. 4-18 Different diameters are � sed for the interproximal spaces and for the palatal and buccal areas. and different grits are used adequate amount of tooth from the correct areas. The different positions of the buccal and palatal shoulders result from the natural differ
. ence in levels.
for prellmmary reductiOn and for fmosh1ng. The short chamfer or rounded shoulder finish line produces the ideal support for feldspathic
ceramic and all-ceramic restorations. Figs 4-31 and 4-31 Excessive longitudinal abrasion of the bur and the loss of a measurement reference can result i n a curled finish line design
that can not be adequately supported and is likely lo break under occlusal force. lt is also difficult for a dental technician lo fabricate a
restoration for this type of incorrect finish line preparation.
10 121
CHAPil '
Fig 4-33 Simple 90-degree shoulder finish line. This design provides support for maximum esthetics and retention. Figs 4-38 and 4-39 Ninety-degree shoulder design could be ideal for preparations with little retention. for extrasulcular preparations. a n d for
restorations using ceramic or resin composite onlays.
Figs 4-4 and 4-35 Buccal and palatal views of a 90-degree shoulder.
Fig 4-40 Cross section of a tooth prepared with a modified chamfer design.
Figs 4-36 and 4-37 Cross section of a tooth illustrating the proximity of the prepared area to the pulp chamber. AI higher magnification. it is
pos.s1ble to see the slight round1ng of the Internal angle. which occurs because the diamond on the very tip of the bur tends to come loose Fig 4-41 Preparation of a modified chamfer finish line. The clinician must keep the bur in contact with the surface being prepared. along the lon
rapidly. gitudinal axis of the tooth. When working on long or surgically lengthened teeth. the finish line looks like a small or mini chamfer. whereas for
short teeth or to address esthetic concerns. the modified chamfer looks like a rounded-off shoulder.
12 12]
CHAPil '
Fig 4-33 Simple 90-degree shoulder finish line. This design provides support for maximum esthetics and retention. Figs 4-38 and 4-39 Ninety-degree shoulder design could be ideal for preparations with little retention. for extrasulcular preparations. a n d for
restorations using ceramic or resin composite onlays.
Figs 4-4 and 4-35 Buccal and palatal views of a 90-degree shoulder.
Fig 4-40 Cross section of a tooth prepared with a modified chamfer design.
Figs 4-36 and 4-37 Cross section of a tooth illustrating the proximity of the prepared area to the pulp chamber. AI higher magnification. it is
pos.s1ble to see the slight round1ng of the Internal angle. which occurs because the diamond on the very tip of the bur tends to come loose Fig 4-41 Preparation of a modified chamfer finish line. The clinician must keep the bur in contact with the surface being prepared. along the lon
rapidly. gitudinal axis of the tooth. When working on long or surgically lengthened teeth. the finish line looks like a small or mini chamfer. whereas for
short teeth or to address esthetic concerns. the modified chamfer looks like a rounded-off shoulder.
12 12]
CHAPTER 4
MODIFIED CHAMFER P R E P A R AT I O N SYSTEM
Modified chamfer design
Figs 4-42 o 4-4 Modified chamfer is versatile and can be adapted to all kinds of restoration margins, all-ceramic (Fig 4-42!. ceramic shoul
der. metallic margin (Fig 4-43). and metal-ceramic micromargin (Fig 4-44).
.. amount of space available for the esthetic material. and 0.18 mm. Each group includes a coarse-grit (180
Therefore, a new chamfer finish line that is close to �m) bur with a so-degree point and two modified
6o degrees has been designed, answering the need chamfer burs of varying grits, one coarse (180 �m)
for a greater area of support for both all-ceramic and and one fine (jo �m) (Figs 4·47 and 4-48).
metal-ceramic materials (Figs 4·4S and 4-46). The clinician must be able to keep half of the bur
in sight to define the depth and location of the fin·
Assembled preparaion kis ish line. A so-degree point diamond bur is the best
An assembled preparation kit is a procedure system instrument for tracing the guide groove (Figs 4-49
that has instruments divided into various shapes and and 4·so). The guide groove may also be made using
Fig 4-45 Counter-chamfer technique permits increased support provided by the thicker metal in the marginal area.
diameters for the different stages in the preparation the modified chamfer bur. with increased stability of the metal during firing. but reduces the space for the ceramic layer.
of the finish line: guide groove creation, peripheral In the preliminary preparation stage immediately Fig 4-46 Modified chamfer design has an angle of roughly 60 degrees and provides better esthetics in the marginal
area even if the thickness of the metal is increased from the counter-chamfer.
delimitation, and margin inishing. It is composed of following the placement of the guide groove, the
groups of three burs with diameters of 0.14, 0.16, clinician uses a coarse-grit modified chamfer bur to .
124 125
CHAPTER 4
MODIFIED CHAMFER P R E P A R AT I O N SYSTEM
Modified chamfer design
Figs 4-42 o 4-4 Modified chamfer is versatile and can be adapted to all kinds of restoration margins, all-ceramic (Fig 4-42!. ceramic shoul
der. metallic margin (Fig 4-43). and metal-ceramic micromargin (Fig 4-44).
.. amount of space available for the esthetic material. and 0.18 mm. Each group includes a coarse-grit (180
Therefore, a new chamfer finish line that is close to �m) bur with a so-degree point and two modified
6o degrees has been designed, answering the need chamfer burs of varying grits, one coarse (180 �m)
for a greater area of support for both all-ceramic and and one fine (jo �m) (Figs 4·47 and 4-48).
metal-ceramic materials (Figs 4·4S and 4-46). The clinician must be able to keep half of the bur
in sight to define the depth and location of the fin·
Assembled preparaion kis ish line. A so-degree point diamond bur is the best
An assembled preparation kit is a procedure system instrument for tracing the guide groove (Figs 4-49
that has instruments divided into various shapes and and 4·so). The guide groove may also be made using
Fig 4-45 Counter-chamfer technique permits increased support provided by the thicker metal in the marginal area.
diameters for the different stages in the preparation the modified chamfer bur. with increased stability of the metal during firing. but reduces the space for the ceramic layer.
of the finish line: guide groove creation, peripheral In the preliminary preparation stage immediately Fig 4-46 Modified chamfer design has an angle of roughly 60 degrees and provides better esthetics in the marginal
area even if the thickness of the metal is increased from the counter-chamfer.
delimitation, and margin inishing. It is composed of following the placement of the guide groove, the
groups of three burs with diameters of 0.14, 0.16, clinician uses a coarse-grit modified chamfer bur to .
124 125
CHAPTER 4
� create the peripheral outline of the preparation, cor The complete preparation system is also avail
recting the initial angle (Figs 4-51 and 4-52) without able in a cylindrical version (kit TD 1272, Komet, by
altering the apical level of the finish line. The clini D. Massironi), which contains nine burs and is used
cian then finishes the prepared tooth using a fine most frequently in preparations involving a single·
grit bur of the same shape and diameter as the pre unit restoration or small fixed partial dentures,
vious one (Rgs 4-53 and 4-54). where there is little space for instruments of various
The modified chamfer system preparation includes diameters (Figs 4-60 to 4·7!l - For more extensive
a kit and two oscillating tips: the ultrasonic point kit cases with multiple preparations or restorations for
(with two points, 0.14 and 0.16) (TO 1073A Komet patients who have undergone crown-lengthening
with EMS instrument device) and the sonic point kit surgery, there is a conical version (kit TD 86o,
(with two points, 0.14 and 0.16) (SF 979 Kava with Komet, by D. Massironi). This kit, which contains six
soninex instrument) (Rg 4-55). There are also two burs, can be very useful in helping the clinician
rounded chisels, 0.14 and 0.16 mm in diameter, for achieve ideal parallelism between the tooth prepa
manual use (DM1 and DM2, Deppeler) (Figs 4- 56 and rations because of a 3-degree conicity and a diame
4-57). The shapes and diameters of the chisels cor ter that is the same as the cylindrical burs (0.16 to
respond to those of the modified chamfer burs and 0.18 mm) (Rgs 4-72 to 4-80).
are specifically designed for completing the finish The modified chamfer kit is a procedure system' l-28
line. They can be used in a clockwise or (by invert comprising a limited number of burs specific to pre
ing the handpiece) counterclockwise direction (Rgs paring a modified chamfer finish line. The burs can
4-58 and 4-59). The chisels have a contra-angle not be used for occlusal reduction, palatal reduction,
design that allows the user to employ the instru or separation, which considerably limits the cost of
ment in all areas of the preparation, provided the the kit while still providing for the practical needs
cutting edge is kept against the shoulder, in con and creativity of the clinician (Fig 4-81).
junction with the longitudinal axis of the tooth. This As stated earlier, the great advantage of this fin
also allows the operator to check for undercuts. ish line design lies in its versatility, which allows it
Rnishing the prepared tooth with a properly pol to be applied to almost every clinical situation and
ished surface is critical for making accurate impres with diferent types of margins, including the metal
sions. If the preparation is excessively rough, the collar (oten used in laboratory cases), metal micro
impression materials may tear.'6 margin coated in ceramic, collarless, and all-ceramic
restorations (Rgs 4-82 to 4-15 7). ..
Figs 4-47 and 4-48 Procedure systems provide the clinician with appropriate working tools. thus reducing stress a n d working times. The prepa
ration kit includes nine points. including two rounded chisels and two types of oscillating devices !sonic and ultrasonic).
Rgs 4-4g and 4-50 Fifty-degree bur used for initial reduction. The pointed tip permits a clear view of the working area. It also causes less
damage to marginal gingiva. as can be seen in the magnified view.
Figs4-51 and 4-52 After the guide groove is prepared. the SO-degree shoulder !see Fig 4-46. fixed points A and 8) is rectified with a modified
chamfer diamond bur tFig 4-52). thus delimiting the periphery and the shoulders final shape.
16
127
CHAPTER 4
� create the peripheral outline of the preparation, cor The complete preparation system is also avail
recting the initial angle (Figs 4-51 and 4-52) without able in a cylindrical version (kit TD 1272, Komet, by
altering the apical level of the finish line. The clini D. Massironi), which contains nine burs and is used
cian then finishes the prepared tooth using a fine most frequently in preparations involving a single·
grit bur of the same shape and diameter as the pre unit restoration or small fixed partial dentures,
vious one (Rgs 4-53 and 4-54). where there is little space for instruments of various
The modified chamfer system preparation includes diameters (Figs 4-60 to 4·7!l - For more extensive
a kit and two oscillating tips: the ultrasonic point kit cases with multiple preparations or restorations for
(with two points, 0.14 and 0.16) (TO 1073A Komet patients who have undergone crown-lengthening
with EMS instrument device) and the sonic point kit surgery, there is a conical version (kit TD 86o,
(with two points, 0.14 and 0.16) (SF 979 Kava with Komet, by D. Massironi). This kit, which contains six
soninex instrument) (Rg 4-55). There are also two burs, can be very useful in helping the clinician
rounded chisels, 0.14 and 0.16 mm in diameter, for achieve ideal parallelism between the tooth prepa
manual use (DM1 and DM2, Deppeler) (Figs 4- 56 and rations because of a 3-degree conicity and a diame
4-57). The shapes and diameters of the chisels cor ter that is the same as the cylindrical burs (0.16 to
respond to those of the modified chamfer burs and 0.18 mm) (Rgs 4-72 to 4-80).
are specifically designed for completing the finish The modified chamfer kit is a procedure system' l-28
line. They can be used in a clockwise or (by invert comprising a limited number of burs specific to pre
ing the handpiece) counterclockwise direction (Rgs paring a modified chamfer finish line. The burs can
4-58 and 4-59). The chisels have a contra-angle not be used for occlusal reduction, palatal reduction,
design that allows the user to employ the instru or separation, which considerably limits the cost of
ment in all areas of the preparation, provided the the kit while still providing for the practical needs
cutting edge is kept against the shoulder, in con and creativity of the clinician (Fig 4-81).
junction with the longitudinal axis of the tooth. This As stated earlier, the great advantage of this fin
also allows the operator to check for undercuts. ish line design lies in its versatility, which allows it
Rnishing the prepared tooth with a properly pol to be applied to almost every clinical situation and
ished surface is critical for making accurate impres with diferent types of margins, including the metal
sions. If the preparation is excessively rough, the collar (oten used in laboratory cases), metal micro
impression materials may tear.'6 margin coated in ceramic, collarless, and all-ceramic
restorations (Rgs 4-82 to 4-15 7). ..
Figs 4-47 and 4-48 Procedure systems provide the clinician with appropriate working tools. thus reducing stress a n d working times. The prepa
ration kit includes nine points. including two rounded chisels and two types of oscillating devices !sonic and ultrasonic).
Rgs 4-4g and 4-50 Fifty-degree bur used for initial reduction. The pointed tip permits a clear view of the working area. It also causes less
damage to marginal gingiva. as can be seen in the magnified view.
Figs4-51 and 4-52 After the guide groove is prepared. the SO-degree shoulder !see Fig 4-46. fixed points A and 8) is rectified with a modified
chamfer diamond bur tFig 4-52). thus delimiting the periphery and the shoulders final shape.
16
127
CHAPTER
Rg 4-53 Bur in motion. about to modify a line traced earlier by the 50-degree bur. Rg 4-54 The preparation is finished with a fine-grit dia Rg 4-60 Clinical case of a z g -year-old woman who presented with a metal-ceramic crown on the maxillary right central incisor. three
mond bur. Rg 4-55 Diamond- coated tips with a modified chamfer shape are powered by sonic and ultrasonic oscillating instruments. They can endodontically treated teeth. and numerous composite restorations. Rg 4-61 Treatment plan in cluded re-treatment of the canals and prepros
be used to reposition and complete the finish line without rotating movements. thus causing no damage to the gingiva. Rg 4-56 Manual round thetic reconstruction with gold posts and cores. The posts and cores have been cemented. Rg 4-62 After an i mpression was taken in elas
ed chosels for f1nosh1ng IDMl and DMZI. w1th shapes and diameters to match the rotating burs. The rounded chisels can work on all sides of tomeric material. a master cast was fabricated in epoxy resin. Rg 4-63 High magnification reveals the shoulder obtained from a modified
the tooth preparations beca � se they are angled so that they can be held in the ideal positions for working in traction movement. The blades chamfer design. There is ample support for all-ceramic or metal-ceramic crowns.Rg 4-64 Four metallic frameworks obtained by means of
are also contra-angled. wh1ch perm1ts the�r use even 1n interproximal and other inaccessible areas. Rg 4-57 Note the congruity of shape 540. of gold and palladium alloy with a micromargin. Rg 4-65 After the opaque layer is brushed on. space remains for the entire margin to
between the rotat1ng bur and the chos � l. Rg 4-58 During completion of the finish line. the chisel must be held against the axis of the tooth. be covered by the esthetic ceramic material.
espwally to check for undercuts or 1rregulant1es 1n the preparation. Rg 4-59 Excellent finish denoting a well-controlled reduction of the
prosthetic plane.
128
19
CHAPTER
Rg 4-53 Bur in motion. about to modify a line traced earlier by the 50-degree bur. Rg 4-54 The preparation is finished with a fine-grit dia Rg 4-60 Clinical case of a z g -year-old woman who presented with a metal-ceramic crown on the maxillary right central incisor. three
mond bur. Rg 4-55 Diamond- coated tips with a modified chamfer shape are powered by sonic and ultrasonic oscillating instruments. They can endodontically treated teeth. and numerous composite restorations. Rg 4-61 Treatment plan in cluded re-treatment of the canals and prepros
be used to reposition and complete the finish line without rotating movements. thus causing no damage to the gingiva. Rg 4-56 Manual round thetic reconstruction with gold posts and cores. The posts and cores have been cemented. Rg 4-62 After an i mpression was taken in elas
ed chosels for f1nosh1ng IDMl and DMZI. w1th shapes and diameters to match the rotating burs. The rounded chisels can work on all sides of tomeric material. a master cast was fabricated in epoxy resin. Rg 4-63 High magnification reveals the shoulder obtained from a modified
the tooth preparations beca � se they are angled so that they can be held in the ideal positions for working in traction movement. The blades chamfer design. There is ample support for all-ceramic or metal-ceramic crowns.Rg 4-64 Four metallic frameworks obtained by means of
are also contra-angled. wh1ch perm1ts the�r use even 1n interproximal and other inaccessible areas. Rg 4-57 Note the congruity of shape 540. of gold and palladium alloy with a micromargin. Rg 4-65 After the opaque layer is brushed on. space remains for the entire margin to
between the rotat1ng bur and the chos � l. Rg 4-58 During completion of the finish line. the chisel must be held against the axis of the tooth. be covered by the esthetic ceramic material.
espwally to check for undercuts or 1rregulant1es 1n the preparation. Rg 4-59 Excellent finish denoting a well-controlled reduction of the
prosthetic plane.
128
19
Figs 4-66 o 4-68 Metal-ceramic restorations with micromargins. The esthetic result is excellent. especially considering that these are porte
lain-fused-to-metal crowns with a metal margin.
Figs 4-69 o 4-71 Detail of the gingival margin. evaluated through a stereomicroscope. Note the integration of the restorations and the soft tis
sues. as well as the healthy gingival margin.
10
Figs 4-66 o 4-68 Metal-ceramic restorations with micromargins. The esthetic result is excellent. especially considering that these are porte
lain-fused-to-metal crowns with a metal margin.
Figs 4-69 o 4-71 Detail of the gingival margin. evaluated through a stereomicroscope. Note the integration of the restorations and the soft tis
sues. as well as the healthy gingival margin.
10
CHAPTER 4
Fig 4-72 Conical abrasive burs. The conical kit (TO 860. conical version) has burs with the same diameters as in the cylindrical version. but a
conicity of 3 degrees: therefore. The 0.14 mm point becomes 0.18 mm at the base of the stem. while the 0.18-mm bur becomes 0.23 mm at
the base. The use of these burs must be limited to cases involving the restoration of multiple teeth and particularly those with advanced peri
odontal disease. The conicity permits the clinician to establish the proper parallelism.
Figs 4-73 and 4-74 Conical diamond held vertically for a good angle of TOC. The clinician must maintain this slant during the operative stage:
the wrong slant would create an undesired angle.
1 133
CHAPTER 4
Fig 4-72 Conical abrasive burs. The conical kit (TO 860. conical version) has burs with the same diameters as in the cylindrical version. but a
conicity of 3 degrees: therefore. The 0.14 mm point becomes 0.18 mm at the base of the stem. while the 0.18-mm bur becomes 0.23 mm at
the base. The use of these burs must be limited to cases involving the restoration of multiple teeth and particularly those with advanced peri
odontal disease. The conicity permits the clinician to establish the proper parallelism.
Figs 4-73 and 4-74 Conical diamond held vertically for a good angle of TOC. The clinician must maintain this slant during the operative stage:
the wrong slant would create an undesired angle.
1 133
Fimsh Line Designs for Complete Crown Prepara l
fig 4-75 Clinical case of a patient with advanced periodontal disease. The patient has already undergone periodontal surgery. and the teeth Fig 4-81 Master cast of a preparation for a molar executed with conical b u rs. fig 4-82 to 4-119
are b11ng prepared. Preservation � f the pulp vitality is a fundamental aspect of treatment. Fig 4-76 Development of the correct axis of the Schematic illustrations simulating tooth preparation with a modified chamfer finish line. fig 4-82
pre.parallon for tak1ng the 1mpres11on and f� r 1nsert1ng the prostheses. The original axis of the tooth 11 marked with a permanent marker to Facial view of a maxillary central incisor. The clinician separates the interproximal area using a
facilitate the reduction The 50-degree bur IS used to separate and create the guide groove. (See also figs 4-48 to 4-59 for more detail on 0.1 0-mm-diameter bur F19 4-83 Cross section of a sagittal view after separation. fig 4-84 Dental
the 1n�trumentat1on.l F1g 4-77 f1nal tooth pre � aralions. f1g 4-78 Occlusal view showing good alignment of the tooth preparations along the structure must be reduced to the purple line to place a metal- ceramic crown The th1ckness
1nsertton path. f1gs 4-79 and 4-80 Master cast 1llustrallng the paralleliSm obta1ned with the use of conical burs. The clinician should evaluate required for each sector is 1ndicated with a millimeter grid. Fig 4-85 Proportional relationship of a
the pmllellsm mesiodistally and palatol1ngually Moreover. the ftn11h line shoulder will offer m1n1mal support area. depending on the length 50- degree. 0.16-mm. coarse-grtt bur with a tooth. Ftgs 4-86 to 4-88 Creat1on of guide grooves. With
of the tooth preparation and the natural ap1cal narrow1ng of the tooth The chamfer will be quite small. even if 1t 1s made with a modified the bur held at about a 45-degree angle. the clin1cian creates a gu1de groove in the labiog1ng1val
chamfer bur. and support a metal-ceramic restoration w1th a metallic margin and palatoging1val margin areas.
14 135
Fimsh Line Designs for Complete Crown Prepara l
fig 4-75 Clinical case of a patient with advanced periodontal disease. The patient has already undergone periodontal surgery. and the teeth Fig 4-81 Master cast of a preparation for a molar executed with conical b u rs. fig 4-82 to 4-119
are b11ng prepared. Preservation � f the pulp vitality is a fundamental aspect of treatment. Fig 4-76 Development of the correct axis of the Schematic illustrations simulating tooth preparation with a modified chamfer finish line. fig 4-82
pre.parallon for tak1ng the 1mpres11on and f� r 1nsert1ng the prostheses. The original axis of the tooth 11 marked with a permanent marker to Facial view of a maxillary central incisor. The clinician separates the interproximal area using a
facilitate the reduction The 50-degree bur IS used to separate and create the guide groove. (See also figs 4-48 to 4-59 for more detail on 0.1 0-mm-diameter bur F19 4-83 Cross section of a sagittal view after separation. fig 4-84 Dental
the 1n�trumentat1on.l F1g 4-77 f1nal tooth pre � aralions. f1g 4-78 Occlusal view showing good alignment of the tooth preparations along the structure must be reduced to the purple line to place a metal- ceramic crown The th1ckness
1nsertton path. f1gs 4-79 and 4-80 Master cast 1llustrallng the paralleliSm obta1ned with the use of conical burs. The clinician should evaluate required for each sector is 1ndicated with a millimeter grid. Fig 4-85 Proportional relationship of a
the pmllellsm mesiodistally and palatol1ngually Moreover. the ftn11h line shoulder will offer m1n1mal support area. depending on the length 50- degree. 0.16-mm. coarse-grtt bur with a tooth. Ftgs 4-86 to 4-88 Creat1on of guide grooves. With
of the tooth preparation and the natural ap1cal narrow1ng of the tooth The chamfer will be quite small. even if 1t 1s made with a modified the bur held at about a 45-degree angle. the clin1cian creates a gu1de groove in the labiog1ng1val
chamfer bur. and support a metal-ceramic restoration w1th a metallic margin and palatoging1val margin areas.
14 135
CH Pl
Fimsh Line Designs for Complete Crown Preparations
Figs4-8g and 4-go Creation of reduction grooves. With the bur held vertically. the clinician places reduction grooves. measuring half the thick Fig 4- g7 Labial rounding. The clinician rounds the labial aspect in keeping with the anatomy and profile of the natural tooth.
ness of the bur. Fig 4- gs Palatal finish line. The clinician corrects the finish line on the palatal aspect.
Fig 4-g 1 Frontal view of reduction grooves. Figs 4-Qg and 4-100 Using a 0.14-mm bur with coarse grit. the clinician connects the shoulder or buccal guide groove with the palatal guide
Figs 4- g2 and 4-gJ labial reduction. The clinician reduces the tooth. following the lines and extension defined by the reduction grooves. groove.
Fig 4-4 Palatal reduction. The clinician carries out the same reduction on the palatal side. starting from the guide groove area and keeping Fig4-101 1ncisal edge grooves. The clinician reduces the incisal edge by making two notches with the 0 . 1 6 - m m bur to the incisal finish line.
the point in constant contact with the tooth surface. Fig 4-102 Frontal view of incisal reduction grooves.
Fig 4- g5 and 4-g6 Modified chamfer bur with a 0.16 - mm diameter and coarse grit.
Fig 4-103 Incisal edge reduction. With the extent of reduction established by the grooves. the clinician reduces the entire incisal edge.
16
7
CH Pl
Fimsh Line Designs for Complete Crown Preparations
Figs4-8g and 4-go Creation of reduction grooves. With the bur held vertically. the clinician places reduction grooves. measuring half the thick Fig 4- g7 Labial rounding. The clinician rounds the labial aspect in keeping with the anatomy and profile of the natural tooth.
ness of the bur. Fig 4- gs Palatal finish line. The clinician corrects the finish line on the palatal aspect.
Fig 4-g 1 Frontal view of reduction grooves. Figs 4-Qg and 4-100 Using a 0.14-mm bur with coarse grit. the clinician connects the shoulder or buccal guide groove with the palatal guide
Figs 4- g2 and 4-gJ labial reduction. The clinician reduces the tooth. following the lines and extension defined by the reduction grooves. groove.
Fig 4-4 Palatal reduction. The clinician carries out the same reduction on the palatal side. starting from the guide groove area and keeping Fig4-101 1ncisal edge grooves. The clinician reduces the incisal edge by making two notches with the 0 . 1 6 - m m bur to the incisal finish line.
the point in constant contact with the tooth surface. Fig 4-102 Frontal view of incisal reduction grooves.
Fig 4- g5 and 4-g6 Modified chamfer bur with a 0.16 - mm diameter and coarse grit.
Fig 4-103 Incisal edge reduction. With the extent of reduction established by the grooves. the clinician reduces the entire incisal edge.
16
7
Fono1h Line Ouignl for Complete Crown Preparatoon• 1
fog 4 14 and 4 lOS CliniCian rtducu hall ol lht eonuvt surface ol lhe ptlalal aru 11 a hmt. u11ng a loolball·shapad bur fogs 4-111 1o 4 113 Repositioning In the onterproxomal area The elonomn repos1toons the finiSh line on the onlorproximal area. using 0 1 4 - m m
fogl 4 16 •nd 4 107 F1n1sh1ng slaga Tht cllnomn uau font grot burs w11h the nmt thape and dlameler at In the reduct1on slage nonrolatlng s o n i c or ultrasonic instruments
fog 4 108 Plaumanl of lht rtlrtcllon cord Tht aua ol lht cord and the uu and type of lmpregnahng toluhon It choun baud on the pero· F1gs 4-114 10 4-116 Relining of the shoulder finish lone with a manual rounded ch111l
odonlal blolypt and lha 1mpreulon malerlll uud F1g 4-117 Finished preparation li the cllnlelan notices a mln1mal homonlal space between the glng1va and the shoulder lln11h line. or a small
fog 4 100 Rtpotlllonlng of lht l1nlsh lint Aflor lht huue is rtlrlcltd. lht el1n1cian uus a bur wllh the ume doamtlor and domension as the area ol lhe tooth not prepared thai is not covered by the retraction cord. the Impression can be made. leaving the llrsl cord 1 n place
ont und prnloualy to rtpo1111on lht 11nlsh lint F1g 4-118 II part of the g1nglval margin 1mpedes the acceu of the 1mpreuoon matenal. a second retraction cord 11 Inserted for homonlol
fog 4 110 Conhnull•on of rtp011l10n1ng Tha cllnomn utabllshu lht ntw gongoval morgon. using 0 1 !-mm oscollallng ullrason1c or tonic retracilon and 11 removed Immediately before lak1ng the impreu1on
lnstrumanlt F1g 4 119 Once a sullable 1mpren1on has been taken. the ciln1clan removu lht retraction cord The g1ng1va w11t return to lht natural level
Il
Fono1h Line Ouignl for Complete Crown Preparatoon• 1
fog 4 14 and 4 lOS CliniCian rtducu hall ol lht eonuvt surface ol lhe ptlalal aru 11 a hmt. u11ng a loolball·shapad bur fogs 4-111 1o 4 113 Repositioning In the onterproxomal area The elonomn repos1toons the finiSh line on the onlorproximal area. using 0 1 4 - m m
fogl 4 16 •nd 4 107 F1n1sh1ng slaga Tht cllnomn uau font grot burs w11h the nmt thape and dlameler at In the reduct1on slage nonrolatlng s o n i c or ultrasonic instruments
fog 4 108 Plaumanl of lht rtlrtcllon cord Tht aua ol lht cord and the uu and type of lmpregnahng toluhon It choun baud on the pero· F1gs 4-114 10 4-116 Relining of the shoulder finish lone with a manual rounded ch111l
odonlal blolypt and lha 1mpreulon malerlll uud F1g 4-117 Finished preparation li the cllnlelan notices a mln1mal homonlal space between the glng1va and the shoulder lln11h line. or a small
fog 4 100 Rtpotlllonlng of lht l1nlsh lint Aflor lht huue is rtlrlcltd. lht el1n1cian uus a bur wllh the ume doamtlor and domension as the area ol lhe tooth not prepared thai is not covered by the retraction cord. the Impression can be made. leaving the llrsl cord 1 n place
ont und prnloualy to rtpo1111on lht 11nlsh lint F1g 4-118 II part of the g1nglval margin 1mpedes the acceu of the 1mpreuoon matenal. a second retraction cord 11 Inserted for homonlol
fog 4 110 Conhnull•on of rtp011l10n1ng Tha cllnomn utabllshu lht ntw gongoval morgon. using 0 1 !-mm oscollallng ullrason1c or tonic retracilon and 11 removed Immediately before lak1ng the impreu1on
lnstrumanlt F1g 4 119 Once a sullable 1mpren1on has been taken. the ciln1clan removu lht retraction cord The g1ng1va w11t return to lht natural level
Il
Finish Line Designs for Complete Crown Preparalion J
Fig 4-120 Clinical case of a patient who exhiblh severe bruxism. The initial clinical situation shows severe abrasions in the maxillary and Fig 4-127 Reduction grooves. Fig 4-128 I ncisal reduction. The clinician reduced the incisal edge minimally because it was necessary to
mandibular anterior Ieeth. as well as numerous necrotic Ieeth resulting from the progressive wear of the tooth surfaces. F1g4-121 To reestab increase the vertical height considerably. Fig 4-129 Once the labial portion of the tooth has been prepared. the clinician connects the labial
lish normal occlusion and incre �se vertical height after orlhognalhic treatment with bile raising. the clinician lengthened the clinical crown and palatal surfaces through the interproximal area. Figs 4-130 and 4-131 Reducing half of the tooth at a time. This technique is ideal for cir
.
and roconloured the bone and g1ng1val marg1ns. Fig 4-122 Changed anatomy and crown exposure after healing period. Fig 4-123 Tooth prepa cumstances that preclude the use of simple grooves. lor surfaces thai are not flat. and lor use with curved burs. With half the canine pre
ration using cylindrical diamond bur kit. The clinician waited 6 months after the surgery for the tissues to heal. The teeth were separated pared. the clinician may compare it with the intact half and evaluate the extent of the reduction. Fig 4-132 Completed tooth reduction. I n a
using a 0.16-mm cylindrical bur with a modified chamfer. ThiS bur can also be used to make the guide grooves. Figs 4-124 and 4-125 Creation patient who exhibits bruxi sm. tooth preparation is principally aimed at providing resistance and function rather than esthetics. Figs 4-133 and
of a gu1de groon. The guide groove extends to the g1ngiva. By keeping the groove above the sulcus the clinician maintains the gingival ref 4-136 Repositioning the gingival margins. The clinician inserts the retraction cord and finishes Ieeth with rotating fine-grit burs.
erence point F1g 4-126 Amount of reduction Is verified using the diameter of the bur.
10 141
Finish Line Designs for Complete Crown Preparalion J
Fig 4-120 Clinical case of a patient who exhiblh severe bruxism. The initial clinical situation shows severe abrasions in the maxillary and Fig 4-127 Reduction grooves. Fig 4-128 I ncisal reduction. The clinician reduced the incisal edge minimally because it was necessary to
mandibular anterior Ieeth. as well as numerous necrotic Ieeth resulting from the progressive wear of the tooth surfaces. F1g4-121 To reestab increase the vertical height considerably. Fig 4-129 Once the labial portion of the tooth has been prepared. the clinician connects the labial
lish normal occlusion and incre �se vertical height after orlhognalhic treatment with bile raising. the clinician lengthened the clinical crown and palatal surfaces through the interproximal area. Figs 4-130 and 4-131 Reducing half of the tooth at a time. This technique is ideal for cir
.
and roconloured the bone and g1ng1val marg1ns. Fig 4-122 Changed anatomy and crown exposure after healing period. Fig 4-123 Tooth prepa cumstances that preclude the use of simple grooves. lor surfaces thai are not flat. and lor use with curved burs. With half the canine pre
ration using cylindrical diamond bur kit. The clinician waited 6 months after the surgery for the tissues to heal. The teeth were separated pared. the clinician may compare it with the intact half and evaluate the extent of the reduction. Fig 4-132 Completed tooth reduction. I n a
using a 0.16-mm cylindrical bur with a modified chamfer. ThiS bur can also be used to make the guide grooves. Figs 4-124 and 4-125 Creation patient who exhibits bruxi sm. tooth preparation is principally aimed at providing resistance and function rather than esthetics. Figs 4-133 and
of a gu1de groon. The guide groove extends to the g1ngiva. By keeping the groove above the sulcus the clinician maintains the gingival ref 4-136 Repositioning the gingival margins. The clinician inserts the retraction cord and finishes Ieeth with rotating fine-grit burs.
erence point F1g 4-126 Amount of reduction Is verified using the diameter of the bur.
10 141
Fimsh Line Des1gns for Complete Crown Preparations j
4- 1 3 8
4- 1 4 5 4- 1 4 6
Fig 4- 135 CliniCal v1ew before repositioning the finish line with nonrolating instruments. Fig 4-136 Finish with ultrasonic tip. Because ultra Fig 4-141 Try-in of mock-up. Fig 4-142 Once adapted, the mock-up became the provisional restoration. permitting normal speech and main
SOniC technology IS not based on rotation, it does not damage the periodontal tissue. Fig 4-137 Anterior teeth alter the first stage of prepara taining a normal lip line. Fig 4-143 Posterior mandi bular provisional restorations. Once the posterior height was b e determined. the clinician
tion f1gs 4-138 and 4- 13g Second-stage promional prostheses on the working cast, alter adaptation and positioning in the patient's mouth. could proceed to adapt the anterior provisional restorations according to the indications. Fig 4-14 Anterior mandibular provision! restora
The anlenor gu1de IS _ not accentuated, but th teeth have been elongated according tions adapted to the height of the posterior restorations. Aller the clinician spot etched the center of the teeth with 37% phosphoric acid for
� to the clinician's instructions. Fig 4-140 Mock-up of
mandibular p �ostheus The mandibular antenor tnth also needed to be lengthened. and ceramic veneers were planned from canine to 20 seconds, a film of resin bonding solution was applied both on the surface of the prepared tooth and inside the provisional. and then poly
can1ne Mandibular prostheses were mocked up according to the pretreatment indications. merized with light. Provisional porcelain laminate veneers are never composed of single veneers. When a significant amount of dentin is
exposed. it is preferable to use a transparent cement (TempBond Clear. Kerr) instead of the bonding solution. Fig 4-145 Finish line analysis on
the master cast. The goat lor the laminate veneer preparation is to save as much tissue as possible. Fig 4-146 Feldspathic porcelain laminate
veneers on the cast.
142 13
Fimsh Line Des1gns for Complete Crown Preparations j
4- 1 3 8
4- 1 4 5 4- 1 4 6
Fig 4- 135 CliniCal v1ew before repositioning the finish line with nonrolating instruments. Fig 4-136 Finish with ultrasonic tip. Because ultra Fig 4-141 Try-in of mock-up. Fig 4-142 Once adapted, the mock-up became the provisional restoration. permitting normal speech and main
SOniC technology IS not based on rotation, it does not damage the periodontal tissue. Fig 4-137 Anterior teeth alter the first stage of prepara taining a normal lip line. Fig 4-143 Posterior mandi bular provisional restorations. Once the posterior height was b e determined. the clinician
tion f1gs 4-138 and 4- 13g Second-stage promional prostheses on the working cast, alter adaptation and positioning in the patient's mouth. could proceed to adapt the anterior provisional restorations according to the indications. Fig 4-14 Anterior mandibular provision! restora
The anlenor gu1de IS _ not accentuated, but th teeth have been elongated according tions adapted to the height of the posterior restorations. Aller the clinician spot etched the center of the teeth with 37% phosphoric acid for
� to the clinician's instructions. Fig 4-140 Mock-up of
mandibular p �ostheus The mandibular antenor tnth also needed to be lengthened. and ceramic veneers were planned from canine to 20 seconds, a film of resin bonding solution was applied both on the surface of the prepared tooth and inside the provisional. and then poly
can1ne Mandibular prostheses were mocked up according to the pretreatment indications. merized with light. Provisional porcelain laminate veneers are never composed of single veneers. When a significant amount of dentin is
exposed. it is preferable to use a transparent cement (TempBond Clear. Kerr) instead of the bonding solution. Fig 4-145 Finish line analysis on
the master cast. The goat lor the laminate veneer preparation is to save as much tissue as possible. Fig 4-146 Feldspathic porcelain laminate
veneers on the cast.
142 13
--.Fimsh Line Designs for Complete Crown Preparations I
Figs 4-154 and 4-155 Clinical situation before and after comp. lete restoration. with increased vertical height. complete crowns. and porcelain
FiQI 4-147 and 4-148 The area is isolated with rubber dam. and the tooth is etched prior to cementation of the veneer.
laminate veneers. The clinician decided to restore the mandibular anter�or teeth w1th veneers mstead of With complete crowns because of the
FiQ 4-149 Natural die preparations immediately prior to cementation. resistance of adhesion. even with parafunctional activity. and the difficulty of preparing the mandibular incisors for metal-ceramic crowns.
FIQ 4-150 Where possible, the clinician preserved pulp vitality. a prime objective in every treatment. Figs 4-156 and 4-157 Mandibular anterior teeth before and after restoration with porcelain laminate veneers. Note the increased vertical height.
FIQ 4-151 Occlusal view of the mandibular arch after cementation of the laminate veneers and metal-ceram1c crowns.
F1QI 4-152 and 4-153 Maxillary anterior restorations after cementation
14 15
--.Fimsh Line Designs for Complete Crown Preparations I
Figs 4-154 and 4-155 Clinical situation before and after comp. lete restoration. with increased vertical height. complete crowns. and porcelain
FiQI 4-147 and 4-148 The area is isolated with rubber dam. and the tooth is etched prior to cementation of the veneer.
laminate veneers. The clinician decided to restore the mandibular anter�or teeth w1th veneers mstead of With complete crowns because of the
FiQ 4-149 Natural die preparations immediately prior to cementation. resistance of adhesion. even with parafunctional activity. and the difficulty of preparing the mandibular incisors for metal-ceramic crowns.
FIQ 4-150 Where possible, the clinician preserved pulp vitality. a prime objective in every treatment. Figs 4-156 and 4-157 Mandibular anterior teeth before and after restoration with porcelain laminate veneers. Note the increased vertical height.
FIQ 4-151 Occlusal view of the mandibular arch after cementation of the laminate veneers and metal-ceram1c crowns.
F1QI 4-152 and 4-153 Maxillary anterior restorations after cementation
14 15
CHAPTER 4
With regard to axial reduction, clinicians general·

. AD DITIONAL G U I D ELI N ES FOR
ly believe it should make possible both the devel
TOOTH PREPARAT I O N
opment or normal periodontal borders and ade
Clinicians have always debated t h e relative merits o r quate resistance and esthetics. For metal restor
different finish lines a n d their application t o a variety ations, a reduction or 0.5 to o.8 mm in the buccal
of clinical situations. One of the criteria for deter· and lingual surfaces appears to be suficient, while
mining the choice or a specific finish line design is for both metal-ceramic and all-ceramic crowns, depths
the type or restorative material used, ie, metal, or 1.0 to 1.5 mm•' are recommended. Occlusal re
metal-ceramic, or all-ceramic. duction ranges from 2.0 to 2.5 mm, according to the
Long chamfer finish lines are usually used with thickness or the posterior teeth and the patient's
cast metal crowns; in this kind or restoration, the age. For all-ceramic restorations, occlusal reductions
reduction depth must be in the range or 0.3 to 0.5 should be about 2.0 mm to develop proper mor
mm, 29 permitting a minimum overall reduction or phology without endangering the health or the
the tooth. pulpal tissue.

For metal-ceramic crowns, clinicians have typi· The recommended values should not be consid
cally used either chamfer, beveled chamfer, shout· ered absolute; they are merely indications for guid
der, or beveled shoulder finish lines. A number of ing the clinician in tooth reduction to create suitable
authorsJ>-JJ found no significant diferences in the space for the restorative materials. The skill and
marginal adaptation or metal-ceramic restorations ability or the dental technician, the condition or the
with any or these inish lines. Some studiesJ• show teeth, and the expectations or the patient all influ
that choosing which finish line to use with metal ence tooth preparation. The silicone guides on the
ceramic crowns should not be based on marginal diagnostic waxup or the final restoration. when sec·
adaptation but rather on esthetic preferences, ease tioned, can be useful to provide the clinician with a
or execution, and type or margin Oe. metal, micro clear view or the amount or available space.
margin, or ceramic).3' The authors' opinion is that the preparation
The recommended thickness or the finish lines is phase is the prologue to obtaining excellence in
1.0 to 1.5 mm, the minimum required for resistance every restorative phase, but many clinicians lack the
and esthetics and the minimum space required for guidelines for performing these steps Oe. separa
achieving an ideal emergence profile.'l-35 Clinical tion, reduction, and finishing).
studies, however, show that these values are rarely The modified chamfer preparation (Figs 4-158 to
achieved in clinical practice.J6. J7 4-168) is a workable system that allows greater ease
For all-ceramic crowns, studies have shown either in obtaining excellent results at diferent stages and
Figs 4-158 to 4-168 Clinical case illustrating the esthetics obtained with the modified chamfer technique.
that the chamfer finish line was far less resistant with varying levels or concentration. It offers an inno
Fig4-158 Preoperative view of a 27-year-old female patient with two metal-ceramic crowns on the maxillary left central a n d lateral incisors.
than the 90-degree shoulder,38- 39 or that no signifi vative design that permits all types or restorations The restorations had been placed 1 year earlier. after a traumatic event. Clinical examination revealed, inadequate esthetic result of the two
crowns. resin composite restorations on the right central and lateral incisors. and that the teeth were excessively short for a person her age
cant diference was round after adhesive cementa· (metal, micromargin, and all-ceramic) and every kind
and in relation to the opposing dentition.
tion.•0 Nevertheless, there is a general concensus or connection-in the complete arch, with many Fig 4-15g Removal of the fixed dental prostheses revealed discolored and inadequate tooth preparations.
that the optimal recommended depth for successful connected teeth, and or course, in the case or a sin- Figs 4-160 After the diagnostic waxup was prepared. the clinician replaced the composite restorations and prepared for two veneers.
all-ceramic crowns is 1 mm.41 gle-unit esthetic crown with feldspathic ceramics. • Fig 4-161 The nonvital teeth were whitened and reconstructed using fiberglass dowels. The finish line for the all-ceramic restorations was
prepared using the modified chamfer technique. Care was taken to leave an adequate support for the planned restoration.
Figs 4-162 and 4-163 Occlusal view of clinical situation. before and after treatment.
lU
147
CHAPTER 4
With regard to axial reduction, clinicians general·

. AD DITIONAL G U I D ELI N ES FOR
ly believe it should make possible both the devel
TOOTH PREPARAT I O N
opment or normal periodontal borders and ade
Clinicians have always debated t h e relative merits o r quate resistance and esthetics. For metal restor
different finish lines a n d their application t o a variety ations, a reduction or 0.5 to o.8 mm in the buccal
of clinical situations. One of the criteria for deter· and lingual surfaces appears to be suficient, while
mining the choice or a specific finish line design is for both metal-ceramic and all-ceramic crowns, depths
the type or restorative material used, ie, metal, or 1.0 to 1.5 mm•' are recommended. Occlusal re
metal-ceramic, or all-ceramic. duction ranges from 2.0 to 2.5 mm, according to the
Long chamfer finish lines are usually used with thickness or the posterior teeth and the patient's
cast metal crowns; in this kind or restoration, the age. For all-ceramic restorations, occlusal reductions
reduction depth must be in the range or 0.3 to 0.5 should be about 2.0 mm to develop proper mor
mm, 29 permitting a minimum overall reduction or phology without endangering the health or the
the tooth. pulpal tissue.

For metal-ceramic crowns, clinicians have typi· The recommended values should not be consid
cally used either chamfer, beveled chamfer, shout· ered absolute; they are merely indications for guid
der, or beveled shoulder finish lines. A number of ing the clinician in tooth reduction to create suitable
authorsJ>-JJ found no significant diferences in the space for the restorative materials. The skill and
marginal adaptation or metal-ceramic restorations ability or the dental technician, the condition or the
with any or these inish lines. Some studiesJ• show teeth, and the expectations or the patient all influ
that choosing which finish line to use with metal ence tooth preparation. The silicone guides on the
ceramic crowns should not be based on marginal diagnostic waxup or the final restoration. when sec·
adaptation but rather on esthetic preferences, ease tioned, can be useful to provide the clinician with a
or execution, and type or margin Oe. metal, micro clear view or the amount or available space.
margin, or ceramic).3' The authors' opinion is that the preparation
The recommended thickness or the finish lines is phase is the prologue to obtaining excellence in
1.0 to 1.5 mm, the minimum required for resistance every restorative phase, but many clinicians lack the
and esthetics and the minimum space required for guidelines for performing these steps Oe. separa
achieving an ideal emergence profile.'l-35 Clinical tion, reduction, and finishing).
studies, however, show that these values are rarely The modified chamfer preparation (Figs 4-158 to
achieved in clinical practice.J6. J7 4-168) is a workable system that allows greater ease
For all-ceramic crowns, studies have shown either in obtaining excellent results at diferent stages and
Figs 4-158 to 4-168 Clinical case illustrating the esthetics obtained with the modified chamfer technique.
that the chamfer finish line was far less resistant with varying levels or concentration. It offers an inno
Fig4-158 Preoperative view of a 27-year-old female patient with two metal-ceramic crowns on the maxillary left central a n d lateral incisors.
than the 90-degree shoulder,38- 39 or that no signifi vative design that permits all types or restorations The restorations had been placed 1 year earlier. after a traumatic event. Clinical examination revealed, inadequate esthetic result of the two
crowns. resin composite restorations on the right central and lateral incisors. and that the teeth were excessively short for a person her age
cant diference was round after adhesive cementa· (metal, micromargin, and all-ceramic) and every kind
and in relation to the opposing dentition.
tion.•0 Nevertheless, there is a general concensus or connection-in the complete arch, with many Fig 4-15g Removal of the fixed dental prostheses revealed discolored and inadequate tooth preparations.
that the optimal recommended depth for successful connected teeth, and or course, in the case or a sin- Figs 4-160 After the diagnostic waxup was prepared. the clinician replaced the composite restorations and prepared for two veneers.
all-ceramic crowns is 1 mm.41 gle-unit esthetic crown with feldspathic ceramics. • Fig 4-161 The nonvital teeth were whitened and reconstructed using fiberglass dowels. The finish line for the all-ceramic restorations was
prepared using the modified chamfer technique. Care was taken to leave an adequate support for the planned restoration.
Figs 4-162 and 4-163 Occlusal view of clinical situation. before and after treatment.
lU
147
CHAPTER 4
Figs 4-14 and 4-165 Close-up views 1 month after cementation. showing excellent esthetic integration. The clinician had placed ceramic Fig 4-166 Patient's smile before treatment.
restorations on the maxillary left central and lateral incisors and porcelain laminate veneers on the maxillary right central and lateral figs 4-167 to 4-168 Patient's smile after treatment. showing improved esthetics in terms of the shape and luminosity of the
incisors. teeth. as welt as an excellent lip line.
11 149
CHAPTER 4
Figs 4-14 and 4-165 Close-up views 1 month after cementation. showing excellent esthetic integration. The clinician had placed ceramic Fig 4-166 Patient's smile before treatment.
restorations on the maxillary left central and lateral incisors and porcelain laminate veneers on the maxillary right central and lateral figs 4-167 to 4-168 Patient's smile after treatment. showing improved esthetics in terms of the shape and luminosity of the
incisors. teeth. as welt as an excellent lip line.
11 149
CHAPTER 4
23. Massironi D. Battistelli A. Sistema di preparazione per 34· Goodacre CJ, Campagni W, Aquilino SA. Tooth prepara·
12. Kashani HG, Khera SC. Gulker lA. The efects of bevel
REFERENCES
corone complete. Masson Protech 2000;J:JS-47· tions for complete crowns: An art based on scientific
angulation on marginal integrity. I Am Dent Assoc 1981;
1. Castellani 0. La Preparazione dei pilastri per corone in 103:882-885. 24. Menghini P, Battaini P. Metallurgia in odontoiatria. Milan: principles. I Prosthet Dent 2001;85:363-376.
metal-ceramica. Bologna: artina, 1994:207-208. 13. Gavelis JW. Morency JD. Riley ED. Sozio RB. The efect Masson. 1997:38-39. 35· Chiche GJ. Pinault A. Esthetics of Anterior Fixed Prostho·
2. Butel EM. Campbell JC. DiFiore PM. Crown margin de· of various inish line preparations on the marginal seal 25. Massironi D. Battistelli A, Pascetta R. La Precisione Nella dontics. Chicago: Quintessence. 1994:86-91, 102-103.
sign: A dental school survey. I Prosthet Dent 1991;65: Restaurazione Protesica. Verona: Resch, 1993. 36. Seymour K, Zou L, Samarawickrama D. Lynch E. Assess·
and occlusal seat of full crown preparations. I Prosthet
303-305. Dent 1981;45: 138-145· 26. Albers H. Impressions: A Text for Selection of Materials ment of shoulder dimensions and angles of porcelain
3- Guastamacchia C. Elementi di ergonomia e pratica pro 14. Mclean JW. Wilson AD. Butt joint versus beveled gold and Techniques. Santa Rosa. A: Alto Books, 1990: bonded to metal crown preparations. J Prosthet Dent
fessionale odontoiatrica. Milan: Masson. 1990:408-4D9. margin in metal-ceramic crowns. J Biomed Mater Res 45-46. 1996;75 =40--411.
4- Peon BK, Smales RJ. Assessment of clinical preparations 1980:14:239-250. 27. Ramp MH. McCracken MS. Mazar RB. Tooth structure 37. Friedlander LD, Munoz A. Goodacre CJ, Doyle MG,
for single gold and ceramometal crowns. Quintessence 15. Syu JZ. Byrne G. Laub LW. Land MF. Influence of finish· loss apical to preparations for fixed partial dentures Moore BK. The efect or tooth preparation design on the
lnt 2001;32:603�10. line geometry on the it of crowns. lnt J Prosthodont when using self·limiting burs. I Prosthet Dent 1998; breaking strength of Dicor crowns: Part t. lnt J Pros·
5. Kuwata M. Atlante a colon sulla tecnologia delle 1993:6:25-30. 79=491-494· thodont 1990;3=159-168.
ricostruzioni ceramo-metalliche. Utet t989;2:2 JS-2SO. 16. Panno V. Vahidi F, Gulker I, Ghalili KM. Evaluation or 28. Moschen I, Berger P. Falk M, Horl R. Horle M, Gausch K. 38. Doyle MG, Munoz . Goodacre CJ. Friedlander LD,
6. Di Febo G. Canevale G, Sterrantino S. Treatment of a the 45·degree labial bevel with a shoulder preparation. Comparison of resin-bonded prosthesis groove paral Moore BK. The efect of tooth preparation design on the
case of advanced periodontitis: Clinical procedures uti 1 Prosthet Dent 1986:56:655�61. lelism with the use of four tooth preparation methods. breaking strength of Dicor crowns: Part 2. tnt J Pros·
..
lizing the .combined preparation technique. tnt J 17. Mitchell A. Pintado MR, Douglas WH. Nondestructive, I Prosthet Dent 1999;82:398-409. thodont 1990:3:241-248.
Periodontics Restorative Dent 1985;5:52�2. in vitro quantification of crown margins. I Prosthet Dent 29. Rosenstiel S. Land MF, Fujimoto J. Contemporary Rxed 39· Bernal G, Jones RM, Brown DT, Munoz A, Goodacre CJ.
7· Nyman S. lindhe J. A longitudinal study of combined 2001;85 : 5 75-584. Prosthodontics. ed 2. St Louis: Mosby, 1995:137-138, The efect of inish line m and luting agent on the
periodontal and prosthetic treatment of patients with 18. Pameijer JHN. Periodontal and Occlusal Fadors in Crown 17o-173. 184-185, 229. breaking strength of Dicor crowns. lnt J Prosthodont
advanced periodontal disease. J Periodontal 1979;50: and Bridge Procedures. Amsterdam: Dental Center for JO. Hamaguchi H, Cacciatore A, Tueller VM. Marginal distor· 1993;6:28&-290.
163-169. Postgraduate Courses. 1985. tion of the porcelain-bonded-to-metal complete crown: 40. Douglas RD. P/bylska M. Predicting porcelain thick·
8. De Soever lA. Fixed restorations of a dentition with re· 19. Kauman EG, Coelho DH, Colin L. Factors inluencing An SEM study. I Prosthet Dent 1982;47:14&-153· ness required for dental shade matches. I Prosthet Dent
duced periodontal support in partially edentulous pa· retention of cemented gold castings. J Prosthet Dent 31. Richter·Snapp K. Aquilino SA, Svare CW, Turner KA. 1999;82:143-149·
tients [in German). Parodontol 1990;1:153-164. 1961;11:487-502. Change in marginal it as related to margin design. alloy 41. Stambaugh RV, Wittrock JW. The relationship of the pulp
9· Siegel SC, Driscoll CF, Feldman S. Tooth stabilization 20. Martignoni M, Shonenberger AJ. Precision Fixed Pros· type, and porcelain proximity in porcelain-fused-to· chamber to the extenal surface of the tooth. I Prosthet
and splinting before and ater periodontal therapy with thodontics: Clinical and Laboratory Aspects. Chicago: metal restorations. I Prosthet Dent 1988;6o:435-439. Dent 1977;37:537-546.
ixed partial dentures. Dent Clin North Am 1999:43: Quintessence, 1990. 32. Belser UC, MacEntee Ml, Richter WA. Fit of three 42. AI·Omari WM. AI·Wahadni AM. Convegence angle, occlu·
45-76. porcelain-fused-to-metal designs in vivo: A scanning sal reduction. and finish line depth of full·crown prepa·
21. Faucher RR. Nicholls 11. Distortion related to margin de·
10. El Ebrashi MK, Craig RG, Peyton FA. Experimental stress sign in porcelain-fused-to-metal restorations. J Prosthet electron microscope study. I Prosthet Dent 1985;53: rations made by dental students. Quintessence tnt 2004;
analysis of dental restorations. Part Ill. The concept of Dent 1980;43=149-155· 24-29. 3 5 :287-293·
geometry of proximal margins. 1 Prosthet Dent 196g; 33· Byrne G. Influence of finish-line form on crown cemen·
22. Zena RB, Khan Z, von Fraunhofer JA. Shoulder prepara·
22:333-345· tation. lnt I Prosthodont 1992;5:137-144.
tions for collarless metal-ceramic crowns: Hand-planning
11. Rosner D. Fundion placement and reproduction of as opposed to rotary instrumentation. J Prosthet Dent
bevels for gold castings. I Prosthet Dent 1963;13:116o.
1989;62:273-277.
IO
151
CHAPTER 4
23. Massironi D. Battistelli A. Sistema di preparazione per 34· Goodacre CJ, Campagni W, Aquilino SA. Tooth prepara·
12. Kashani HG, Khera SC. Gulker lA. The efects of bevel
REFERENCES
corone complete. Masson Protech 2000;J:JS-47· tions for complete crowns: An art based on scientific
angulation on marginal integrity. I Am Dent Assoc 1981;
1. Castellani 0. La Preparazione dei pilastri per corone in 103:882-885. 24. Menghini P, Battaini P. Metallurgia in odontoiatria. Milan: principles. I Prosthet Dent 2001;85:363-376.
metal-ceramica. Bologna: artina, 1994:207-208. 13. Gavelis JW. Morency JD. Riley ED. Sozio RB. The efect Masson. 1997:38-39. 35· Chiche GJ. Pinault A. Esthetics of Anterior Fixed Prostho·
2. Butel EM. Campbell JC. DiFiore PM. Crown margin de· of various inish line preparations on the marginal seal 25. Massironi D. Battistelli A, Pascetta R. La Precisione Nella dontics. Chicago: Quintessence. 1994:86-91, 102-103.
sign: A dental school survey. I Prosthet Dent 1991;65: Restaurazione Protesica. Verona: Resch, 1993. 36. Seymour K, Zou L, Samarawickrama D. Lynch E. Assess·
and occlusal seat of full crown preparations. I Prosthet
303-305. Dent 1981;45: 138-145· 26. Albers H. Impressions: A Text for Selection of Materials ment of shoulder dimensions and angles of porcelain
3- Guastamacchia C. Elementi di ergonomia e pratica pro 14. Mclean JW. Wilson AD. Butt joint versus beveled gold and Techniques. Santa Rosa. A: Alto Books, 1990: bonded to metal crown preparations. J Prosthet Dent
fessionale odontoiatrica. Milan: Masson. 1990:408-4D9. margin in metal-ceramic crowns. J Biomed Mater Res 45-46. 1996;75 =40--411.
4- Peon BK, Smales RJ. Assessment of clinical preparations 1980:14:239-250. 27. Ramp MH. McCracken MS. Mazar RB. Tooth structure 37. Friedlander LD, Munoz A. Goodacre CJ, Doyle MG,
for single gold and ceramometal crowns. Quintessence 15. Syu JZ. Byrne G. Laub LW. Land MF. Influence of finish· loss apical to preparations for fixed partial dentures Moore BK. The efect or tooth preparation design on the
lnt 2001;32:603�10. line geometry on the it of crowns. lnt J Prosthodont when using self·limiting burs. I Prosthet Dent 1998; breaking strength of Dicor crowns: Part t. lnt J Pros·
5. Kuwata M. Atlante a colon sulla tecnologia delle 1993:6:25-30. 79=491-494· thodont 1990;3=159-168.
ricostruzioni ceramo-metalliche. Utet t989;2:2 JS-2SO. 16. Panno V. Vahidi F, Gulker I, Ghalili KM. Evaluation or 28. Moschen I, Berger P. Falk M, Horl R. Horle M, Gausch K. 38. Doyle MG, Munoz . Goodacre CJ. Friedlander LD,
6. Di Febo G. Canevale G, Sterrantino S. Treatment of a the 45·degree labial bevel with a shoulder preparation. Comparison of resin-bonded prosthesis groove paral Moore BK. The efect of tooth preparation design on the
case of advanced periodontitis: Clinical procedures uti 1 Prosthet Dent 1986:56:655�61. lelism with the use of four tooth preparation methods. breaking strength of Dicor crowns: Part 2. tnt J Pros·
..
lizing the .combined preparation technique. tnt J 17. Mitchell A. Pintado MR, Douglas WH. Nondestructive, I Prosthet Dent 1999;82:398-409. thodont 1990:3:241-248.
Periodontics Restorative Dent 1985;5:52�2. in vitro quantification of crown margins. I Prosthet Dent 29. Rosenstiel S. Land MF, Fujimoto J. Contemporary Rxed 39· Bernal G, Jones RM, Brown DT, Munoz A, Goodacre CJ.
7· Nyman S. lindhe J. A longitudinal study of combined 2001;85 : 5 75-584. Prosthodontics. ed 2. St Louis: Mosby, 1995:137-138, The efect of inish line m and luting agent on the
periodontal and prosthetic treatment of patients with 18. Pameijer JHN. Periodontal and Occlusal Fadors in Crown 17o-173. 184-185, 229. breaking strength of Dicor crowns. lnt J Prosthodont
advanced periodontal disease. J Periodontal 1979;50: and Bridge Procedures. Amsterdam: Dental Center for JO. Hamaguchi H, Cacciatore A, Tueller VM. Marginal distor· 1993;6:28&-290.
163-169. Postgraduate Courses. 1985. tion of the porcelain-bonded-to-metal complete crown: 40. Douglas RD. P/bylska M. Predicting porcelain thick·
8. De Soever lA. Fixed restorations of a dentition with re· 19. Kauman EG, Coelho DH, Colin L. Factors inluencing An SEM study. I Prosthet Dent 1982;47:14&-153· ness required for dental shade matches. I Prosthet Dent
duced periodontal support in partially edentulous pa· retention of cemented gold castings. J Prosthet Dent 31. Richter·Snapp K. Aquilino SA, Svare CW, Turner KA. 1999;82:143-149·
tients [in German). Parodontol 1990;1:153-164. 1961;11:487-502. Change in marginal it as related to margin design. alloy 41. Stambaugh RV, Wittrock JW. The relationship of the pulp
9· Siegel SC, Driscoll CF, Feldman S. Tooth stabilization 20. Martignoni M, Shonenberger AJ. Precision Fixed Pros· type, and porcelain proximity in porcelain-fused-to· chamber to the extenal surface of the tooth. I Prosthet
and splinting before and ater periodontal therapy with thodontics: Clinical and Laboratory Aspects. Chicago: metal restorations. I Prosthet Dent 1988;6o:435-439. Dent 1977;37:537-546.
ixed partial dentures. Dent Clin North Am 1999:43: Quintessence, 1990. 32. Belser UC, MacEntee Ml, Richter WA. Fit of three 42. AI·Omari WM. AI·Wahadni AM. Convegence angle, occlu·
45-76. porcelain-fused-to-metal designs in vivo: A scanning sal reduction. and finish line depth of full·crown prepa·
21. Faucher RR. Nicholls 11. Distortion related to margin de·
10. El Ebrashi MK, Craig RG, Peyton FA. Experimental stress sign in porcelain-fused-to-metal restorations. J Prosthet electron microscope study. I Prosthet Dent 1985;53: rations made by dental students. Quintessence tnt 2004;
analysis of dental restorations. Part Ill. The concept of Dent 1980;43=149-155· 24-29. 3 5 :287-293·
geometry of proximal margins. 1 Prosthet Dent 196g; 33· Byrne G. Influence of finish-line form on crown cemen·
22. Zena RB, Khan Z, von Fraunhofer JA. Shoulder prepara·
22:333-345· tation. lnt I Prosthodont 1992;5:137-144.
tions for collarless metal-ceramic crowns: Hand-planning
11. Rosner D. Fundion placement and reproduction of as opposed to rotary instrumentation. J Prosthet Dent
bevels for gold castings. I Prosthet Dent 1963;13:116o.
1989;62:273-277.
IO
151
C H A P T E R 5
R E P OSITI O NING AN D C O M P LETI NG

THE F I NISH L I NE WITH
OSC I L LATI NG I NST R U M E NTS
R
epositioning of the finish line is accom retraction procedures. Traditionally, the finish line is
FIG 5-1 FIG 5-2
plished before the definitive impression is repositioned during the impression-taking stage.
taken and approximately 3 weeks' after the This involves retracting the gingival tissues in the
preliminay preparation phase has been completed. prepared areas to accurately assess the intact tooth
The procedure requires the level of the finish line to structure beyond the inish line.
LEVEL FOR THE FINISH LIN E P O S I TI O N

be adjusted and the preparation to be refined to a
more apical position immediately afier gingival de·
OSC I L LATI N G I N STRUM ENTS
A N EW
lection (Fig 5·1).
In the initial stage of tooth preparation, a non· Sonic and ultrasonic instruments may be used to
impregnated retraction cord is placed to retract the reposition and complete the finish line. Originally
gingival tissues apically, thus making the inish line developed for finishing the interproximal boxes of
accessible. With this increased accessibility, an exact inlay preparations.' the instruments were gradually
finish line can be designed and inalized with one of adopted for the delicate stage of repositioning the
the preparation techniques described in chapter 4· inish line {Figs 5-2 and 5-3) because of the need for
Since placement of a provisional prosthesis with cor instrument tips that could replace the classic rotating
rect morphology will stimulate the development of instruments. which many clinicians have dificulty
the gingiva, the deinitive impression is rarely made controlling near the gingiva. Damage to the sulcular
at this stage. An average of 3 weeks' is recom and parasulcular gingival tissues often causes bleed·
mended for the development of adequate gingival ing, reducing the efectiveness of the impression ma·
tissue prior to initiating the various sofi tissue terials and the precision of impressions in general. .
Fig 5-1 Preparation lor an all-ceramic crown. There is a lack of space. with the finish line and the gingival sulcus in close
contact. Making an impression under such conditions would lead to failure.
figs 5-2 and 5-3 Images of a coarse-grit bur !stationary and in motion! used with a rotating handpiece lor conventional tooth
preparation. II insufficiently controlled during use. the diamond bur can come into contact with the gingiva and cause lesions
on the soft tissue. Bleeding impedes proper impression taking of the finish line and of the intact tooth beyond the finish t i ne .
FIG 5-3
152
C H A P T E R 5
R E P OSITI O NING AN D C O M P LETI NG

THE F I NISH L I NE WITH
OSC I L LATI NG I NST R U M E NTS
R
epositioning of the finish line is accom retraction procedures. Traditionally, the finish line is
FIG 5-1 FIG 5-2
plished before the definitive impression is repositioned during the impression-taking stage.
taken and approximately 3 weeks' after the This involves retracting the gingival tissues in the
preliminay preparation phase has been completed. prepared areas to accurately assess the intact tooth
The procedure requires the level of the finish line to structure beyond the inish line.
LEVEL FOR THE FINISH LIN E P O S I TI O N

be adjusted and the preparation to be refined to a
more apical position immediately afier gingival de·
OSC I L LATI N G I N STRUM ENTS
A N EW
lection (Fig 5·1).
In the initial stage of tooth preparation, a non· Sonic and ultrasonic instruments may be used to
impregnated retraction cord is placed to retract the reposition and complete the finish line. Originally
gingival tissues apically, thus making the inish line developed for finishing the interproximal boxes of
accessible. With this increased accessibility, an exact inlay preparations.' the instruments were gradually
finish line can be designed and inalized with one of adopted for the delicate stage of repositioning the
the preparation techniques described in chapter 4· inish line {Figs 5-2 and 5-3) because of the need for
Since placement of a provisional prosthesis with cor instrument tips that could replace the classic rotating
rect morphology will stimulate the development of instruments. which many clinicians have dificulty
the gingiva, the deinitive impression is rarely made controlling near the gingiva. Damage to the sulcular
at this stage. An average of 3 weeks' is recom and parasulcular gingival tissues often causes bleed·
mended for the development of adequate gingival ing, reducing the efectiveness of the impression ma·
tissue prior to initiating the various sofi tissue terials and the precision of impressions in general. .
Fig 5-1 Preparation lor an all-ceramic crown. There is a lack of space. with the finish line and the gingival sulcus in close
contact. Making an impression under such conditions would lead to failure.
figs 5-2 and 5-3 Images of a coarse-grit bur !stationary and in motion! used with a rotating handpiece lor conventional tooth
preparation. II insufficiently controlled during use. the diamond bur can come into contact with the gingiva and cause lesions
on the soft tissue. Bleeding impedes proper impression taking of the finish line and of the intact tooth beyond the finish t i ne .
FIG 5-3
152
CHAPTER 5
Repositioning and Completing the Finish Line with Oscillating Instuments
. Furthermore, if the lesions develop on thin peri· Ultrasonic power is controlled by the amplitude
odontal tissue or are extensive, more serious com· of oscillation, which is between so and 70 �m (not,
plications could result, threatening the stability of as some might expect, by the frequency of the
the dentogingival complex and even resulting in waves emitted, which ranges from 28,ooo to 32.ooo
unattractive gingival recession. Hz and cannot be controlled by the operator). The
To prevent gingival damage, the authors devel· clinician regulates the intensity of oscillation to
oped ultrasonic and sonic diamond-coated tips with modulate the abrasive effect and expand the range
medium grit that are designed to be mounted on of application. When an ultrasonic instrument is FIG 5-4
piezoelectric and pneumatic grips, respectivelyl Be· used at maximum oscillation, the tip can abrade
cause ultrasonic and sonic technology work with dentin with a progressive tissue-removal effect that
oscillating rather than rotating movement, these can easily be controlled even by an inexperienced
instruments do not damage adjacent gingival tissue operator. Such a high degree of control thus permits
during preparation.• A kit of ultrasonic instruments the clinician to reposition the finish line without the
TD 1073A; ISO.IJJ.014 or ISO.IJJ.016, Komet) is risk of creating lesions on the marginal gingiva (Figs
available with tips duplicating the shape of the s·7 to s·tO). At the lowest level, the tip can create
modified chamfer' (see chapter 4) for completing well-polished and well-defined surfaces comparable
the finish line on complete crown preparations (Fig to those obtained using a medium-grit (about 7S �m)
s-4). When using ultrasonic instruments at the gin· rotating diamond bur (Fig S·ll).
gival margin, tips should have an average grit of 91 Therefore, ultra-coarse-grit (ISO· to 180-�m),
�m and a working surface of 9 mm in length. The medium-grit (107·�m), and fine-grit (Jo-�m) rotating
clinician will also need tip diameters of 0.14 and diamond burs and a rounded chisel as a manual
0.16 mm (ISO.IJJ.014 and ISO.IJJ.016), compatible instrument were used. These were compared with
with the bur diameters most frequently used in oscillating ultrasonic and sonic instruments, the lat·
preparing complete crowns (Figs s·s and s·6). ter set at three different power levels (high, medium,
Repeated in vitro and clinical tests with proto· and low). FIG 5-5
types of these tips demonstrated that they not only In this study (shown in Table S·l), both average
inish preparations with a high degree of precision, roughness (which is most important) and maximum
but also reposition the level of the finish line more roughness values were obtained. The results
apically when necessary. showed that the ultra-coarse- and medium-grit burs ..
Fig 5-4 K i t co �taining oscillating- � onrotating (ultrasonic! margin-positioning and finishing tips (designed by D. Massironi.
Italy!. These t1ps have the sam � diameters 10.14 and 0.16 mm) and shape as rotating modified chamfer burs. They serve to
_
repos1t1on and complete the finiSh line preparation using oscillation rather than rotating movement.
Fig 5-5 Prototype diamo � d tips. Several prototypes. with differently positioned diamond layers and different grits were
d � s1gned and tested. Initially. th � tops were sectioned l �ngitudinally. with the flat part to be in contact with the gingival mar
gin. The 1neff1c1ent des1gn was d1scarded because the l1ps only worked on one side of the preparation and easily broke.
Fig 5-6 Diamond grits from 15 to 125 pm were tested. but the best results were obtained using a 9 1 - pm grit.
14 FIG 5-6
CHAPTER 5
. Furthermore, if the lesions develop on thin peri· Ultrasonic power is controlled by the amplitude
odontal tissue or are extensive, more serious com· of oscillation, which is between so and 70 �m (not,
plications could result, threatening the stability of as some might expect, by the frequency of the
the dentogingival complex and even resulting in waves emitted, which ranges from 28,ooo to 32.ooo
unattractive gingival recession. Hz and cannot be controlled by the operator). The
To prevent gingival damage, the authors devel· clinician regulates the intensity of oscillation to
oped ultrasonic and sonic diamond-coated tips with modulate the abrasive effect and expand the range
medium grit that are designed to be mounted on of application. When an ultrasonic instrument is FIG 5-4
piezoelectric and pneumatic grips, respectivelyl Be· used at maximum oscillation, the tip can abrade
cause ultrasonic and sonic technology work with dentin with a progressive tissue-removal effect that
oscillating rather than rotating movement, these can easily be controlled even by an inexperienced
instruments do not damage adjacent gingival tissue operator. Such a high degree of control thus permits
during preparation.• A kit of ultrasonic instruments the clinician to reposition the finish line without the
TD 1073A; ISO.IJJ.014 or ISO.IJJ.016, Komet) is risk of creating lesions on the marginal gingiva (Figs
available with tips duplicating the shape of the s·7 to s·tO). At the lowest level, the tip can create
modified chamfer' (see chapter 4) for completing well-polished and well-defined surfaces comparable
the finish line on complete crown preparations (Fig to those obtained using a medium-grit (about 7S �m)
s-4). When using ultrasonic instruments at the gin· rotating diamond bur (Fig S·ll).
gival margin, tips should have an average grit of 91 Therefore, ultra-coarse-grit (ISO· to 180-�m),
�m and a working surface of 9 mm in length. The medium-grit (107·�m), and fine-grit (Jo-�m) rotating
clinician will also need tip diameters of 0.14 and diamond burs and a rounded chisel as a manual
0.16 mm (ISO.IJJ.014 and ISO.IJJ.016), compatible instrument were used. These were compared with
with the bur diameters most frequently used in oscillating ultrasonic and sonic instruments, the lat·
preparing complete crowns (Figs s·s and s·6). ter set at three different power levels (high, medium,
Repeated in vitro and clinical tests with proto· and low). FIG 5-5
types of these tips demonstrated that they not only In this study (shown in Table S·l), both average
inish preparations with a high degree of precision, roughness (which is most important) and maximum
but also reposition the level of the finish line more roughness values were obtained. The results
apically when necessary. showed that the ultra-coarse- and medium-grit burs ..
Fig 5-4 K i t co �taining oscillating- � onrotating (ultrasonic! margin-positioning and finishing tips (designed by D. Massironi.
Italy!. These t1ps have the sam � diameters 10.14 and 0.16 mm) and shape as rotating modified chamfer burs. They serve to
_
repos1t1on and complete the finiSh line preparation using oscillation rather than rotating movement.
Fig 5-5 Prototype diamo � d tips. Several prototypes. with differently positioned diamond layers and different grits were
d � s1gned and tested. Initially. th � tops were sectioned l �ngitudinally. with the flat part to be in contact with the gingival mar
gin. The 1neff1c1ent des1gn was d1scarded because the l1ps only worked on one side of the preparation and easily broke.
Fig 5-6 Diamond grits from 15 to 125 pm were tested. but the best results were obtained using a 9 1 - pm grit.
14 FIG 5-6
CHAPTER 5
Repositioning and Completing the Finish line with Oscillating Instruments
.. and the ultrasonic and sonic instruments performed perpendicular to the direction of oscillation, the efect
poorly at the maximum working power, while the is vey much reduced, or even nullified. Wavelength is
sonic instrument at low power achieved a finishing directly proportional to speed in that shot waves
effect similar to that using fine- and medium-grit move at high speeds. In the case of ultrasonic waves,
burs, and in some aspects a manual rounded chisel. it is possible to reach a frequency of 32,000 Hz, but
These results demonstrate how a change in heat the working area is vey small because the amplitude
intensity alters the effectiveness of the tool. At high of oscillation (../2) is very small, resulting in a limited
power, the ultrasonic and sonic instruments are per number of diamond granules working in a single direc
fectly suitable for repositioning the finish line of a tion. Because the ultrasonic tip works at high oscilla FIG 5-8 FIG 5-9 FIG 5-10
FIG 5-7
preparation, but at lower levels their effect is limit· tions, it produces a surface that does not appear
ed to polishing and finishing. smooth and uniform, but the tool works very efi
ciently if the tip is kept properly oriented.
The sonic instrument (Sonicflex, KaVa) uses a
Fig 5-7 Although lhe tip is in contact with the gingiva. there are no
CO M PARING SONIC AND pneumatic feed and requires insertion of a multi flex visible lesions. It i s important to irrigate the tool with a stream of
water to avoid overheating the tip and the prepared tooth. or it
U LTRAS O N I C I N STRUM ENTS attachment in place of the high-speed air turbine. could result in the formation of a superficial lesion on the soft lis
The multiflex attachment is composed of a hollow sues.
A comparison of sonic and ultrasonic instruments cylinder with an interior sheath or tube with to lat Fig 5-8 Tooth preparation for a fixed partial denture. The ultrasonic
tip is being used to reposition the finish line more apically.
highlights the diferent characteristics of each.6 The eral holes. The cylinder rotates as a result of pres Figs 5-9 and 5-10 Degree of finishing and condition of the gingiva
ultrasonic instrument is electric: An alternating cur surized air that the operator controls with a pedal following repositioning. at high magnification. The tissue is free of
lesions and bleeding.
rent produces a series of volumetric contractions in switch. The oscillation frequency (around 6,ooo Hz)
Fig 5-11 Surface of a tooth prepared using an ultrasonic lip. This
quart2 cystals, which generate localized propaga is much lower than that of the ultrasonic instrument image shows the difference i n surface quality obtained with two
levels of oscillation intensity. AI higher oscillation, the surface
70
takes on irregularities (large area). w h i le at lower oscillation the
tion waves (peak to peak, between so and �m) but generates a three-dimensional elliptical move
in a restricted area with bidirectional and linear ment, with both longitudinal and transversal com surface appears smoothly polished (small area).
FIG 5-11
movement. The diamond-coated tips can be used ponents, that renders the entire tip active. The sonic
only on the ultrasonic tool or grip, which features tip will abrade the surface of the tooth regardless of
front and rear resonance chambers on either side of its position relative to the tooth.
the middle cystals. The rear resonance chambers The amplitude of the oscillation has a peak
are triggered by an activator and transform the wave to-peak range of 120 to 250 �m. sufficient For a
from longitudinal to transversal. The sound wave TABLE 5-1 Degree of roughness obtained with rotating, ultrasonic, and manual
rotational movement on small surfaces. It creates a
thus creates an oscillation in the tip, which is coat instruments
less abrasive efect than ultrasonic instruments and
ed with diamond granules. allows a greater working area at the tip. With its Average Maximum
The abrasive efect of the tip depends on the 64-�m-grit diamond layer, pneumatic feed, and grip Instrument roughness* (tm) roughnesst (Jm)
amplitude /2) between two waves; the smaller the regulated intensity (Ievet t, range amplitude [raj = 120 Ultra-coarse-grit (t8o-�m) bur 24.3 51.8
diameter of the tip, the closer together the waves are : 15 �m; level 2, ra = 160 : 15 �m; level 3, ra = 250 Medium-grit (107-�m) bur 14.2 35.1
and the more the tip oscillates. Because the wave : 15 �m), the sonic tool can be used effectively to Fine-grit (30-�m) bur 8.9 13.1
moves in a linear ashion, the oscillation produces reposition the finish line and finish the suraces. Ultrasonic instrument (EMS) 15.4 23.5
Sonic (Sonicflex) instrument, minimum power 12.6 19.0
maximum tissue removal when the tip is aligned with The authors have used various diamond grits (eg,
Sonic (Sonicflex) instrument, maximum power 16.9 28.3
the direction of wave movement. If t he t i p is orient ed 21, 46, and 91 �m) and have discovered that both .. Rounded chisel, manual action 7.2 15.3
•Average roughness (R7) i s t h e mean value obtained from t h e single roughness values of ive subsequent measuring lengths i n
the roughness profile.
'Maximum roughness (R max) is the highest of the five single roughness values.
16 17
CHAPTER 5
Repositioning and Completing the Finish line with Oscillating Instruments
.. and the ultrasonic and sonic instruments performed perpendicular to the direction of oscillation, the efect
poorly at the maximum working power, while the is vey much reduced, or even nullified. Wavelength is
sonic instrument at low power achieved a finishing directly proportional to speed in that shot waves
effect similar to that using fine- and medium-grit move at high speeds. In the case of ultrasonic waves,
burs, and in some aspects a manual rounded chisel. it is possible to reach a frequency of 32,000 Hz, but
These results demonstrate how a change in heat the working area is vey small because the amplitude
intensity alters the effectiveness of the tool. At high of oscillation (../2) is very small, resulting in a limited
power, the ultrasonic and sonic instruments are per number of diamond granules working in a single direc
fectly suitable for repositioning the finish line of a tion. Because the ultrasonic tip works at high oscilla FIG 5-8 FIG 5-9 FIG 5-10
FIG 5-7
preparation, but at lower levels their effect is limit· tions, it produces a surface that does not appear
ed to polishing and finishing. smooth and uniform, but the tool works very efi
ciently if the tip is kept properly oriented.
The sonic instrument (Sonicflex, KaVa) uses a
Fig 5-7 Although lhe tip is in contact with the gingiva. there are no
CO M PARING SONIC AND pneumatic feed and requires insertion of a multi flex visible lesions. It i s important to irrigate the tool with a stream of
water to avoid overheating the tip and the prepared tooth. or it
U LTRAS O N I C I N STRUM ENTS attachment in place of the high-speed air turbine. could result in the formation of a superficial lesion on the soft lis
The multiflex attachment is composed of a hollow sues.
A comparison of sonic and ultrasonic instruments cylinder with an interior sheath or tube with to lat Fig 5-8 Tooth preparation for a fixed partial denture. The ultrasonic
tip is being used to reposition the finish line more apically.
highlights the diferent characteristics of each.6 The eral holes. The cylinder rotates as a result of pres Figs 5-9 and 5-10 Degree of finishing and condition of the gingiva
ultrasonic instrument is electric: An alternating cur surized air that the operator controls with a pedal following repositioning. at high magnification. The tissue is free of
lesions and bleeding.
rent produces a series of volumetric contractions in switch. The oscillation frequency (around 6,ooo Hz)
Fig 5-11 Surface of a tooth prepared using an ultrasonic lip. This
quart2 cystals, which generate localized propaga is much lower than that of the ultrasonic instrument image shows the difference i n surface quality obtained with two
levels of oscillation intensity. AI higher oscillation, the surface
70
takes on irregularities (large area). w h i le at lower oscillation the
tion waves (peak to peak, between so and �m) but generates a three-dimensional elliptical move
in a restricted area with bidirectional and linear ment, with both longitudinal and transversal com surface appears smoothly polished (small area).
FIG 5-11
movement. The diamond-coated tips can be used ponents, that renders the entire tip active. The sonic
only on the ultrasonic tool or grip, which features tip will abrade the surface of the tooth regardless of
front and rear resonance chambers on either side of its position relative to the tooth.
the middle cystals. The rear resonance chambers The amplitude of the oscillation has a peak
are triggered by an activator and transform the wave to-peak range of 120 to 250 �m. sufficient For a
from longitudinal to transversal. The sound wave TABLE 5-1 Degree of roughness obtained with rotating, ultrasonic, and manual
rotational movement on small surfaces. It creates a
thus creates an oscillation in the tip, which is coat instruments
less abrasive efect than ultrasonic instruments and
ed with diamond granules. allows a greater working area at the tip. With its Average Maximum
The abrasive efect of the tip depends on the 64-�m-grit diamond layer, pneumatic feed, and grip Instrument roughness* (tm) roughnesst (Jm)
amplitude /2) between two waves; the smaller the regulated intensity (Ievet t, range amplitude [raj = 120 Ultra-coarse-grit (t8o-�m) bur 24.3 51.8
diameter of the tip, the closer together the waves are : 15 �m; level 2, ra = 160 : 15 �m; level 3, ra = 250 Medium-grit (107-�m) bur 14.2 35.1
and the more the tip oscillates. Because the wave : 15 �m), the sonic tool can be used effectively to Fine-grit (30-�m) bur 8.9 13.1
moves in a linear ashion, the oscillation produces reposition the finish line and finish the suraces. Ultrasonic instrument (EMS) 15.4 23.5
Sonic (Sonicflex) instrument, minimum power 12.6 19.0
maximum tissue removal when the tip is aligned with The authors have used various diamond grits (eg,
Sonic (Sonicflex) instrument, maximum power 16.9 28.3
the direction of wave movement. If t he t i p is orient ed 21, 46, and 91 �m) and have discovered that both .. Rounded chisel, manual action 7.2 15.3
•Average roughness (R7) i s t h e mean value obtained from t h e single roughness values of ive subsequent measuring lengths i n
the roughness profile.
'Maximum roughness (R max) is the highest of the five single roughness values.
16 17
CHAPTER 5
Repositioning and Completing the Finish Line with Oscillating Instruments
� larger and smaller grits can be used effectively for case, a gingival lesion and subsequent blood now � finish line. The lack of rotation is the instruments' mond granules eventually fall of (Fig 5-25) . Such
the removal of dentin, as well as for simple polish would jeopardize the outcome of the impression. most important feature, permitting ideal control. With problems are not unique to sonic and ultrasonic
ing. The production of tips with diferent grits and From years of experimentation to improve sonic the possibility of modulating the oscillation intensity instruments, since breaks also occur in scaling in·
diameters is expected so that a full range of oscillat and ultrasonic instruments, the authors have had of the instrument, the clinician is able to reposition struments (Fig 5-26). However, these instruments
ing implements will be available (Figs 5-12 to 5-21). ample opportunity to determine their optimal use. and complete the finish line without causing even should be examined fai rly regularly under magnifica
The choice between an ultrasonic or sonic system The first requirement of sonic and ultrasonic instru minimal lesions in the marginal gingiva. tion and replaced when they start to show signs of
is often dictated more by the type of system cur ments is internal irrigation to prevent overheating The surface obtained by using the sonic instru wear. The degree of wear is proportional to the
rently available in an oice, rather than by marked that may damage dentin and pulp and to avoid ments is irregular, with a pockmarked appearance number of teeth prepared but far less than the com
preference or understanding of operational differ breaking the diamond tips. The sonic and ultrasonic (Figs 5-22 and 5-23), unlike the circular little grooves parable wear of rotating tips. In the authors' experi
ences. A sonic tool will vibrate constantly, regardless tools need about 15 and 30 ml/min of water respec that are produced by a rotating diamond bur. In ence, the instruments need to be replaced, on aver
of the operating pressure, producing a good efect tively for cooling.8·9 The presence of water between theory, such a surface should provide better adhe age, two or three times per year.
that removes dentinal tissue during the repositioning the tip and the tooth surface can result in an unde sion by permitting the cement to cover more area. In clinical practice, a retraction cord is inserted to
of the finish line. The ultrasonic tool, with its bi sirable hydroplaning effect. similar to the situation According to the literature,'0 the ideal degree of pol obtain the vertical displacement of the gingival tis
directional oscillation, works optimally only when that occurs between a car tire and a wet road. The ishing of dental preparations, which can be mea sue, and the sonic or ultrasonic instrument is used
the operator matches the working direction to that liquid layer nullifies the oscillating effect of the sured with a roughness profilometer, is between 5 in combination with a stereomicroscope, initially in
of the wave. The preparation of a surface through instrument, and the dental assistant must aim inter and 10 �m. Below this value, the cement adheres direct view of the buccal area and then in indi rect
widespread removal of tissue yields a better result mittent jets of air at the prepared tooth to restore less efectively to the surfaces of the prepared tooth, view of the palatal area and interproximal relation
when sonic instruments are used. Moreover, because normal functioning. while above 12 �m the cement does not spread ships of all the teeth involved (Figs 5-27 and 5-28).
the elliptical movement is more convenient and the Another requirement for ideal functioning of an evenly, leaving uncemented spots." The exceptional control provided by oscillating instru
intensity of the sonic instrument can be easily regu ultrasonic instrument is the proper difusion and Diamond tips used with sonic and ultrasonic ments prevents damage to the paramarginal gingiva
lated to create uniform and well-polished surfaces, direction of the ultrasonic waves that are generated instruments have greater longevity than diamond and thus provides a more accessible finish line dur
the sonic system is easier for the clinician to master' in the handle by the quartz crystals, which oscillate burs used with rotating instruments. Oscillation of ing the inishing and i mpression stages (Figs 5-29 to
in response to the piezoelectric stimulation. These the tips keeps wear to a minimum by avoiding the 5-37). Taking the impression will also be made eas-
waves pass through the grip and the cuvature of the stress of high-speed rotation and limiting the stress ier by the absence of gingival lesions. I n addition,
OPTI MAL USE OF OSCI LLATI NG stem to the tip, where their intensity is at its peak, to the abrasion of the tooth surface. the continuous irrigation with intermittent water and
I N STRUM ENTS with the exception of the two linear areas distal and These instruments can break if used improperly air spray results, in most cases, in the need for only
mesial to the tip. If the instrument is positioned or without water (Fig 5-24). and, as is true for all one retraction cord, with obvious benefits for the ac
In addition to the versatility of oscillating instru curve on nat. it will have the least effect because instruments with an abrasive diamond layer, the dia- curacy of the planned finish line (Figs 5-38 to 5-47). •
ments, their greatest advantage is lack of rotation, that area of the tip is free of waves. If the tip is sim
which permits absolute control during the most del ply rotated a few degrees, it will function perfectly,
icate stages of preparation and reduces the risk of although its best efect will still be above and below
gingival lesions. This also benefits impression mak the point of the wave's maximum peak.
ing because it eliminates the need to remove blood In the author's opinion, the use of sonic and ultra
from the area before making an impression. Oscillat· sonic instruments constitutes an innovative system of
ing instruments are particularly useful when nonim preparation. While they do not replace rotating instru
pregnated retraction cords are used, resulting in ments in the preparation stage, these instruments can
minimal vertical retraction of the gingiva; in such a be of great value in repositioning and completing the .
11
159
CHAPTER 5
� larger and smaller grits can be used effectively for case, a gingival lesion and subsequent blood now � finish line. The lack of rotation is the instruments' mond granules eventually fall of (Fig 5-25) . Such
the removal of dentin, as well as for simple polish would jeopardize the outcome of the impression. most important feature, permitting ideal control. With problems are not unique to sonic and ultrasonic
ing. The production of tips with diferent grits and From years of experimentation to improve sonic the possibility of modulating the oscillation intensity instruments, since breaks also occur in scaling in·
diameters is expected so that a full range of oscillat and ultrasonic instruments, the authors have had of the instrument, the clinician is able to reposition struments (Fig 5-26). However, these instruments
ing implements will be available (Figs 5-12 to 5-21). ample opportunity to determine their optimal use. and complete the finish line without causing even should be examined fai rly regularly under magnifica
The choice between an ultrasonic or sonic system The first requirement of sonic and ultrasonic instru minimal lesions in the marginal gingiva. tion and replaced when they start to show signs of
is often dictated more by the type of system cur ments is internal irrigation to prevent overheating The surface obtained by using the sonic instru wear. The degree of wear is proportional to the
rently available in an oice, rather than by marked that may damage dentin and pulp and to avoid ments is irregular, with a pockmarked appearance number of teeth prepared but far less than the com
preference or understanding of operational differ breaking the diamond tips. The sonic and ultrasonic (Figs 5-22 and 5-23), unlike the circular little grooves parable wear of rotating tips. In the authors' experi
ences. A sonic tool will vibrate constantly, regardless tools need about 15 and 30 ml/min of water respec that are produced by a rotating diamond bur. In ence, the instruments need to be replaced, on aver
of the operating pressure, producing a good efect tively for cooling.8·9 The presence of water between theory, such a surface should provide better adhe age, two or three times per year.
that removes dentinal tissue during the repositioning the tip and the tooth surface can result in an unde sion by permitting the cement to cover more area. In clinical practice, a retraction cord is inserted to
of the finish line. The ultrasonic tool, with its bi sirable hydroplaning effect. similar to the situation According to the literature,'0 the ideal degree of pol obtain the vertical displacement of the gingival tis
directional oscillation, works optimally only when that occurs between a car tire and a wet road. The ishing of dental preparations, which can be mea sue, and the sonic or ultrasonic instrument is used
the operator matches the working direction to that liquid layer nullifies the oscillating effect of the sured with a roughness profilometer, is between 5 in combination with a stereomicroscope, initially in
of the wave. The preparation of a surface through instrument, and the dental assistant must aim inter and 10 �m. Below this value, the cement adheres direct view of the buccal area and then in indi rect
widespread removal of tissue yields a better result mittent jets of air at the prepared tooth to restore less efectively to the surfaces of the prepared tooth, view of the palatal area and interproximal relation
when sonic instruments are used. Moreover, because normal functioning. while above 12 �m the cement does not spread ships of all the teeth involved (Figs 5-27 and 5-28).
the elliptical movement is more convenient and the Another requirement for ideal functioning of an evenly, leaving uncemented spots." The exceptional control provided by oscillating instru
intensity of the sonic instrument can be easily regu ultrasonic instrument is the proper difusion and Diamond tips used with sonic and ultrasonic ments prevents damage to the paramarginal gingiva
lated to create uniform and well-polished surfaces, direction of the ultrasonic waves that are generated instruments have greater longevity than diamond and thus provides a more accessible finish line dur
the sonic system is easier for the clinician to master' in the handle by the quartz crystals, which oscillate burs used with rotating instruments. Oscillation of ing the inishing and i mpression stages (Figs 5-29 to
in response to the piezoelectric stimulation. These the tips keeps wear to a minimum by avoiding the 5-37). Taking the impression will also be made eas-
waves pass through the grip and the cuvature of the stress of high-speed rotation and limiting the stress ier by the absence of gingival lesions. I n addition,
OPTI MAL USE OF OSCI LLATI NG stem to the tip, where their intensity is at its peak, to the abrasion of the tooth surface. the continuous irrigation with intermittent water and
I N STRUM ENTS with the exception of the two linear areas distal and These instruments can break if used improperly air spray results, in most cases, in the need for only
mesial to the tip. If the instrument is positioned or without water (Fig 5-24). and, as is true for all one retraction cord, with obvious benefits for the ac
In addition to the versatility of oscillating instru curve on nat. it will have the least effect because instruments with an abrasive diamond layer, the dia- curacy of the planned finish line (Figs 5-38 to 5-47). •
ments, their greatest advantage is lack of rotation, that area of the tip is free of waves. If the tip is sim
which permits absolute control during the most del ply rotated a few degrees, it will function perfectly,
icate stages of preparation and reduces the risk of although its best efect will still be above and below
gingival lesions. This also benefits impression mak the point of the wave's maximum peak.
ing because it eliminates the need to remove blood In the author's opinion, the use of sonic and ultra
from the area before making an impression. Oscillat· sonic instruments constitutes an innovative system of
ing instruments are particularly useful when nonim preparation. While they do not replace rotating instru
pregnated retraction cords are used, resulting in ments in the preparation stage, these instruments can
minimal vertical retraction of the gingiva; in such a be of great value in repositioning and completing the .
11
159
C IAIT R
F1g 5-12 Sonic grip and tips. The sonic instrument usu pneumatic power and elliptical low-frequency. 6-MHz waves to produce good finish fig 5-16 Use of sonic instrument prior to the positioning of a retraction cord.
linu. Tips are available in diameters of 0.14 and 0.16 mm !Sf 919.000.014 and Sf 919.000.016. Kamel). fig 5-17 Healthy gingiva. after placement of the vertical retraction cord and during the apical repositioning of the finish line.
Fig 5-13 Prototype sonic lips with varying stem curvature radii. The straight stem (not available) transmits greater vibration and oscillation
than the curved stem and causes more discomfort for the patient.
f1gs 5-14 1nd 5-15 Sonic lip poSitioned along the long axis of the tooth. The advantage of the sonic tool is thai it works e q ually well in all posi
tions and direc11ons. unlike the ullruonlt Instrument.
lG 111
C IAIT R
F1g 5-12 Sonic grip and tips. The sonic instrument usu pneumatic power and elliptical low-frequency. 6-MHz waves to produce good finish fig 5-16 Use of sonic instrument prior to the positioning of a retraction cord.
linu. Tips are available in diameters of 0.14 and 0.16 mm !Sf 919.000.014 and Sf 919.000.016. Kamel). fig 5-17 Healthy gingiva. after placement of the vertical retraction cord and during the apical repositioning of the finish line.
Fig 5-13 Prototype sonic lips with varying stem curvature radii. The straight stem (not available) transmits greater vibration and oscillation
than the curved stem and causes more discomfort for the patient.
f1gs 5-14 1nd 5-15 Sonic lip poSitioned along the long axis of the tooth. The advantage of the sonic tool is thai it works e q ually well in all posi
tions and direc11ons. unlike the ullruonlt Instrument.
lG 111
CHA . .
Figs 5-18 and 5-1 g Stereomicroscope views of finish line before and after apical repositioning with the pneumatic sonic instrument (magnifi Figs 5-20 and 5-21 New position of the finish line achieved easily and without trauma using the sonic tool following placement of only one
cation X 25). impregnated retraction cord !magnification x 2 5).
112
CHA . .
Figs 5-18 and 5-1 g Stereomicroscope views of finish line before and after apical repositioning with the pneumatic sonic instrument (magnifi Figs 5-20 and 5-21 New position of the finish line achieved easily and without trauma using the sonic tool following placement of only one
cation X 25). impregnated retraction cord !magnification x 2 5).
112
CHAPTER 5
Figs 5-22 and 5-23 Two polyether impressions of the same molar. The surface of the first impression has the regular. horizontal lines from treat
ment with a rotating bur. In the second impression. the irregular. pockmarked surface and absence of horizontal lines results from the oscil
lation of an ultrasonic instrument. Fig 5-24 Broken stem of an ultrasonic instrument. after use. Fig 5-25 Ultrasonic tip showing wear i n the dia
mond grit. Oscillating tips are subject to less wear than traditional burs. because there is no rotation impact. Fig 5-16 Broken tools used to
remove calcified tartar and plaque. Figs 5-27 and 5-28 Correct repositioning and completion of finish line using an ultrasonic instrument. with
placement of one retraction cord. The finish line has shifted apically without evident alteration at the gingival level. Fig 5-29 Clinical case
involving the removal of an inadequate metal-ceramic restoration. A well-integrated provisional prosthesis has been placed for finishing and
taking the impression.
14 15
CHAPTER 5
Figs 5-22 and 5-23 Two polyether impressions of the same molar. The surface of the first impression has the regular. horizontal lines from treat
ment with a rotating bur. In the second impression. the irregular. pockmarked surface and absence of horizontal lines results from the oscil
lation of an ultrasonic instrument. Fig 5-24 Broken stem of an ultrasonic instrument. after use. Fig 5-25 Ultrasonic tip showing wear i n the dia
mond grit. Oscillating tips are subject to less wear than traditional burs. because there is no rotation impact. Fig 5-16 Broken tools used to
remove calcified tartar and plaque. Figs 5-27 and 5-28 Correct repositioning and completion of finish line using an ultrasonic instrument. with
placement of one retraction cord. The finish line has shifted apically without evident alteration at the gingival level. Fig 5-29 Clinical case
involving the removal of an inadequate metal-ceramic restoration. A well-integrated provisional prosthesis has been placed for finishing and
taking the impression.
14 15
CHAPTER 5
5·3 1
fig 5-30 Prepared tooth after the first preparation. prior to adaptation of the provisional. Fig 5-32 Position of the gingiva and its close contact with the finish tine would compromise the impression without adequate retraction.
fig 5-31 Frontal view through the stereomicroscope. Note the healthy gingiva prior to placement of the retraction cord. fig 5-33 Displacement of the gingival tissue (Gingi-Aid Z-Twist no. 00. Gingi Paki.The retraction cord vertically deflects the gingiva. The clin
ician can easily measure the extent of this displacement in relation to the level of the finish line before retraction to calculate the juxta
gingival placement of the prosthetic margin during repositioning.
fig 5-4 Note the horizontal displacement caused by the retraction cord and the vertical distance between the cord and the finish line.
14 167
CHAPTER 5
5·3 1
fig 5-30 Prepared tooth after the first preparation. prior to adaptation of the provisional. Fig 5-32 Position of the gingiva and its close contact with the finish tine would compromise the impression without adequate retraction.
fig 5-31 Frontal view through the stereomicroscope. Note the healthy gingiva prior to placement of the retraction cord. fig 5-33 Displacement of the gingival tissue (Gingi-Aid Z-Twist no. 00. Gingi Paki.The retraction cord vertically deflects the gingiva. The clin
ician can easily measure the extent of this displacement in relation to the level of the finish line before retraction to calculate the juxta
gingival placement of the prosthetic margin during repositioning.
fig 5-4 Note the horizontal displacement caused by the retraction cord and the vertical distance between the cord and the finish line.
14 167
CHAPTER \
Fig 5-35 Oscillating tip during apical repositioning of the finish line. The lack of rotation permits precise control. and the soft tissue shows no Figs 5-38 and 5-39 B u ccal and palatal views of working cast in epoxy resin. before epoxy die trimming. The horizontal space delineated by the
sign of damage. retraction cord allows the clinician to easily evaluate the finish line. without doubts about extension.
Figs 5-36 and 5-37 Manual chisel during the finishing stage. High magnification shows the dentinal debris removed during polishing. Fig 5-0 Captek metal structure (leach & Dillon) realized on the master cast.
11 169
CHAPTER \
Fig 5-35 Oscillating tip during apical repositioning of the finish line. The lack of rotation permits precise control. and the soft tissue shows no Figs 5-38 and 5-39 B u ccal and palatal views of working cast in epoxy resin. before epoxy die trimming. The horizontal space delineated by the
sign of damage. retraction cord allows the clinician to easily evaluate the finish line. without doubts about extension.
Figs 5-36 and 5-37 Manual chisel during the finishing stage. High magnification shows the dentinal debris removed during polishing. Fig 5-0 Captek metal structure (leach & Dillon) realized on the master cast.
11 169
Repoa1tlonmg nd Completing the Flm h Line w1lh 0 clllalmg Instruments ]
5·43
F1g � 41 Captek metal structure tluch & 011tonl. trlld In the pat11nt's mouth Fig 5-43 Preoperative view o f clinical case.
f1g I 42 Cond111on al the g1ng1va during the try-1n 1nd1talt1 the clinician's rupect lor the tluuu In adaplltlon of the provisional and in the flgs S-4 Definitive metal-ceramic crown with integrated g1ngival marg1n
t1k1ng of the lmprtulon
170 171
Repoa1tlonmg nd Completing the Flm h Line w1lh 0 clllalmg Instruments ]
5·43
F1g � 41 Captek metal structure tluch & 011tonl. trlld In the pat11nt's mouth Fig 5-43 Preoperative view o f clinical case.
f1g I 42 Cond111on al the g1ng1va during the try-1n 1nd1talt1 the clinician's rupect lor the tluuu In adaplltlon of the provisional and in the flgs S-4 Definitive metal-ceramic crown with integrated g1ngival marg1n
t1k1ng of the lmprtulon
170 171
CHAPTER 5
7. Schmidlin PR, Beuchat M, Busslinger A, Lehmann 8,

REFERENCES
lutz F. Tooth substance loss resulting from mechanical.
1. Wilson RD. Maynard G. lntracrevicular restorative den sonic and ultrasonic root instrumentation assessed by
tistry. lnt J Periodontics Restorative Dent t98t;t:J4-49- liquid scintillation. I Clin Periodontal 2001;28:1058-1o66.
2. Krejci I, Lutz F, Krejci D. Schall· ultraschallbetriebene 8. Zesewitz H. Klaiber 8, Hot2 P, Hugo B. Heat propagation
diamantierte lnstrumente zur Kavitatenpraparation. zum in dentin during cavity preparation in vitro with oscil·
Konturieren und zum Rnieren. ZWR t995:to4:78t-786. lating instruments [in Germani. Schweiiz Monatsschr
3· Kocher . Plagmann HC. The diamond-coated sonic Zahnmed 2005;115:536-541.
scaler tip. Part II: loss of substance and alteration of 9· Kocher T, Plagmann HC. Heat propagation in dentin
root surface texture after diferent scaling modalities. lnt during instrumentation with diferent sonic scaler tips.
I Periodontics Restorative Dent 1997:17:484-493. Quintessence lnt 1996;27:259-264.
4- Massironi 0. 'utilizzo di strumenti diamantati non 10. Gilde H. Lenz P, Richter U. Experimentelle und statis ·
rotanti a funzionamento ultrasonico. Teamwork 2001;3: tiche Untersuchungen zur Pr�parationsmethodik. Otsch
26-34· Zahnarztl z 1984:39:798-800.
s- Massironi D. Banistelli A Sistema di preparazione per n. Wegmann U. Quality of ground enamel suraces and
corone complete. Masson Protech 2000;J :JS-47- preparation margins [in German). Dtsch Zahnarztl Z
6. Drisko CL, Cochran DL, Blieden T, et al. Postion paper: 1985:40=472-478.
Sonic and ultrasonic scalers in periodontics. Research,
Science and Therapy Committee of the American
Academy of Periodontology. I Periodontal 2000;71:
1792-1801.
Figs 5-45 and 5-46 Excellent integration ol the metal-ceramic restoration with the gingiva alter cementation.
Fig 5-47 Lateral view of clinical adaptation of the restoration margin through the stereomicroscope.
172
173
CHAPTER 5
7. Schmidlin PR, Beuchat M, Busslinger A, Lehmann 8,

REFERENCES
lutz F. Tooth substance loss resulting from mechanical.
1. Wilson RD. Maynard G. lntracrevicular restorative den sonic and ultrasonic root instrumentation assessed by
tistry. lnt J Periodontics Restorative Dent t98t;t:J4-49- liquid scintillation. I Clin Periodontal 2001;28:1058-1o66.
2. Krejci I, Lutz F, Krejci D. Schall· ultraschallbetriebene 8. Zesewitz H. Klaiber 8, Hot2 P, Hugo B. Heat propagation
diamantierte lnstrumente zur Kavitatenpraparation. zum in dentin during cavity preparation in vitro with oscil·
Konturieren und zum Rnieren. ZWR t995:to4:78t-786. lating instruments [in Germani. Schweiiz Monatsschr
3· Kocher . Plagmann HC. The diamond-coated sonic Zahnmed 2005;115:536-541.
scaler tip. Part II: loss of substance and alteration of 9· Kocher T, Plagmann HC. Heat propagation in dentin
root surface texture after diferent scaling modalities. lnt during instrumentation with diferent sonic scaler tips.
I Periodontics Restorative Dent 1997:17:484-493. Quintessence lnt 1996;27:259-264.
4- Massironi 0. 'utilizzo di strumenti diamantati non 10. Gilde H. Lenz P, Richter U. Experimentelle und statis ·
rotanti a funzionamento ultrasonico. Teamwork 2001;3: tiche Untersuchungen zur Pr�parationsmethodik. Otsch
26-34· Zahnarztl z 1984:39:798-800.
s- Massironi D. Banistelli A Sistema di preparazione per n. Wegmann U. Quality of ground enamel suraces and
corone complete. Masson Protech 2000;J :JS-47- preparation margins [in German). Dtsch Zahnarztl Z
6. Drisko CL, Cochran DL, Blieden T, et al. Postion paper: 1985:40=472-478.
Sonic and ultrasonic scalers in periodontics. Research,
Science and Therapy Committee of the American
Academy of Periodontology. I Periodontal 2000;71:
1792-1801.
Figs 5-45 and 5-46 Excellent integration ol the metal-ceramic restoration with the gingiva alter cementation.
Fig 5-47 Lateral view of clinical adaptation of the restoration margin through the stereomicroscope.
172
173
C H A P T E R 6
T E C H N I C A L C O N S I D E R AT I O N S F O R
S O FT T I S S U E R ET RACT I O N
6-2
G
ingival retraction requires healthy periodontal Supragingival restoration margins are considered
tissue that is free of pathology and inflam to be most favorable for oral health, in part because
mation (Figs 6-1 to 6-3). Accurate analysis of of their greater accessibility.' The supragingival posi
the periodontal tissue should be performed during tion provides access during all stages of treatment:
the diagnostic stage to identify periodontal disease. tooth preparation, finishing, impression taking, try·
anomalies, or insufficient supporting tissue (Figs 6·4 in, and cementation. Despite the advantage of greater
and 6-5). Gingival probing is essential for evaluating access, the supragingival restoration margin offers
periodontal health and deciding whether surgery is poor esthetics; it is generally indicated for the lingual
necessary. Prosthetic restoration can begin only after aspect of prepared teeth.
the clinical condition of the gingiva has been identi A finish line in a juxtagingival position is more
fied and phase one treatment has been completed. esthetic but lies closer to the gingival tissue. The
When taking impressions, the clinician should verify juxtagingival restoration margin is used for the buc
the gingival biotype to determine how to proceed cal aspect of mandibular molars and premolars.
with the gingival displacement (Figs 6-6 to 6-9). The intracrevicular position is best for addressing
esthetic concerns or for the following indications2: a
need for greater retention and resistance because of
DETERM I N I N G THE POSITION O F i ncreased height and surface area of the restoration;
THE RESTORATION MARGIN presence of caries or old restorations at the margin,
requiring an apical shift to find healthy dental struc 6·5
ture; or the problem of an accentuated radicular sen

Fin ish line positions
sitivity in prepared teeth.
Restoration margins can be placed in one of three In the past, the position of a restoration margin
Fig 6-1 Healthy periodontium is indispensable for successful gingival retraction. figs 6-2 and 6-3 Gingival margin with natural dentition !at 24 x
areas of the gingiva: supragingival, iuxtagingival, or was thought to be the cause of periodontal lesions and 50 X magnification). Figs 6-4 and 6-5 Periodontal probing and analysis of the keratinized tissue help to classify the gingival biotype and
intracrevicular. and other problems, but today the influence of the .. to ensure stability and integrity of the restoration margin over lime.
174
C H A P T E R 6
T E C H N I C A L C O N S I D E R AT I O N S F O R
S O FT T I S S U E R ET RACT I O N
6-2
G
ingival retraction requires healthy periodontal Supragingival restoration margins are considered
tissue that is free of pathology and inflam to be most favorable for oral health, in part because
mation (Figs 6-1 to 6-3). Accurate analysis of of their greater accessibility.' The supragingival posi
the periodontal tissue should be performed during tion provides access during all stages of treatment:
the diagnostic stage to identify periodontal disease. tooth preparation, finishing, impression taking, try·
anomalies, or insufficient supporting tissue (Figs 6·4 in, and cementation. Despite the advantage of greater
and 6-5). Gingival probing is essential for evaluating access, the supragingival restoration margin offers
periodontal health and deciding whether surgery is poor esthetics; it is generally indicated for the lingual
necessary. Prosthetic restoration can begin only after aspect of prepared teeth.
the clinical condition of the gingiva has been identi A finish line in a juxtagingival position is more
fied and phase one treatment has been completed. esthetic but lies closer to the gingival tissue. The
When taking impressions, the clinician should verify juxtagingival restoration margin is used for the buc
the gingival biotype to determine how to proceed cal aspect of mandibular molars and premolars.
with the gingival displacement (Figs 6-6 to 6-9). The intracrevicular position is best for addressing
esthetic concerns or for the following indications2: a
need for greater retention and resistance because of
DETERM I N I N G THE POSITION O F i ncreased height and surface area of the restoration;
THE RESTORATION MARGIN presence of caries or old restorations at the margin,
requiring an apical shift to find healthy dental struc 6·5
ture; or the problem of an accentuated radicular sen

Fin ish line positions
sitivity in prepared teeth.
Restoration margins can be placed in one of three In the past, the position of a restoration margin
Fig 6-1 Healthy periodontium is indispensable for successful gingival retraction. figs 6-2 and 6-3 Gingival margin with natural dentition !at 24 x
areas of the gingiva: supragingival, iuxtagingival, or was thought to be the cause of periodontal lesions and 50 X magnification). Figs 6-4 and 6-5 Periodontal probing and analysis of the keratinized tissue help to classify the gingival biotype and
intracrevicular. and other problems, but today the influence of the .. to ensure stability and integrity of the restoration margin over lime.
174
CHAPTER 6
Technical Considerations for Soft Tissue Retraction
. position is regarded as secondary. As Richter-Snapp Analyzing the dento g i n g ival complex

et al J concluded, "the adaptation, the precision, and
the quality of the restoration margin can be of The term biologic width was coined in 1962,4 but the
greater significance in terms of gingival health. than first studies to measure its components were com·
the position of the margin itself." pleted by Gargiulo et aJS in 1961 and taken up 20
Today, margin positioning is influenced to a large years later by Dragoo and Williams 6·7 These re
extent by patients' demand for esthetics. Clinicians searchers established the mean dimensions of peri·
odontal tissue as follows: gingival sulcus. o.69 mm; FIG 6-6 FIG 6-7
execute intracrevicular margins for maxillary and man·
dlbular anterior segments and sometimes for restora junctional epithelium. 0.97 mm; and connective tis·
tions as distal as second premolars. while juxtagin sue. 1.07 mm. The mean dimension of the biologic
glval margins are reserved for the lingual surfaces of width is 2.04 mm (0.97 + 1.07 mm). Although opin·
all prepared teeth. However, when finalizing a pros· ions diverge, most clinicians agree that biologic
thesis for a patient who has been treated for ad· width is an inviolable gingival limit.
vanced periodontal disease or has considerable gin· Polemics continue. however, over which gingival
gival recession. practical considerations outweigh components are included in the biologic width and
esthetics. and the margins must be positioned supra· their mean dimensions. Vacek et ai8 conducted a study
gingivally. of 10 cadaveric arches to measure the connective tis
When the patient has insufficient keratinized tis sue. the epithelium. and the related loss and depth
sue. and related complications prohibit surgery, the of the sulcus. Their results showed that the connec·
clinician must alter the finish line design. By working tive tissue had a mean thickness of o.n : 0.32 m m ;
at the buccal aspect with a 90-degree rounded shout· t h e junctional epithelium. 1 . 1 4 + 0-49 mm; a n d t h e
der or a modified chamfer preparation. the clinician gingival sulcus. 1 . 3 4 + o.84 mm. I n daily practice,
can complete the restoration with a collarless pros· the biologic width is often intruded upon. especially
thesis (Fig 6-10). When a patient requires intracrevic in the interproximal and buccal areas. and less fre·
ular margins, the clinician should be able to deter quently in the palatal region, whether by mistake or
mine its feasibility during the diagnostic stage by due to carelessness. Violation of the biologic width
classifying the periodontal biotype and evaluating the generally causes inflammation of the circular fibers.
clinical situation (Figs 6-u to 6-14). even in areas not adjacent to the site of damage. ..
FIG 6-8 FIG 6-9
Fig 6-6 Absence of kerati � ized tiss � e around a � andibular right canine. � n this case. intrasulcular positioning of the finish l1ne is impossi
.
ble. F1gs 6 - 7to 6-9 Analysis of kerat1n1zed tissue 1n a pat10nt With a ceramic crown on the mmllary right central incisor. The periodontal bio
type is thick. wh1ch is evident under high magnification and espemlly in a lateral v1ew.
171
m
CHAPTER 6
. position is regarded as secondary. As Richter-Snapp Analyzing the dento g i n g ival complex

et al J concluded, "the adaptation, the precision, and
the quality of the restoration margin can be of The term biologic width was coined in 1962,4 but the
greater significance in terms of gingival health. than first studies to measure its components were com·
the position of the margin itself." pleted by Gargiulo et aJS in 1961 and taken up 20
Today, margin positioning is influenced to a large years later by Dragoo and Williams 6·7 These re
extent by patients' demand for esthetics. Clinicians searchers established the mean dimensions of peri·
odontal tissue as follows: gingival sulcus. o.69 mm; FIG 6-6 FIG 6-7
execute intracrevicular margins for maxillary and man·
dlbular anterior segments and sometimes for restora junctional epithelium. 0.97 mm; and connective tis·
tions as distal as second premolars. while juxtagin sue. 1.07 mm. The mean dimension of the biologic
glval margins are reserved for the lingual surfaces of width is 2.04 mm (0.97 + 1.07 mm). Although opin·
all prepared teeth. However, when finalizing a pros· ions diverge, most clinicians agree that biologic
thesis for a patient who has been treated for ad· width is an inviolable gingival limit.
vanced periodontal disease or has considerable gin· Polemics continue. however, over which gingival
gival recession. practical considerations outweigh components are included in the biologic width and
esthetics. and the margins must be positioned supra· their mean dimensions. Vacek et ai8 conducted a study
gingivally. of 10 cadaveric arches to measure the connective tis
When the patient has insufficient keratinized tis sue. the epithelium. and the related loss and depth
sue. and related complications prohibit surgery, the of the sulcus. Their results showed that the connec·
clinician must alter the finish line design. By working tive tissue had a mean thickness of o.n : 0.32 m m ;
at the buccal aspect with a 90-degree rounded shout· t h e junctional epithelium. 1 . 1 4 + 0-49 mm; a n d t h e
der or a modified chamfer preparation. the clinician gingival sulcus. 1 . 3 4 + o.84 mm. I n daily practice,
can complete the restoration with a collarless pros· the biologic width is often intruded upon. especially
thesis (Fig 6-10). When a patient requires intracrevic in the interproximal and buccal areas. and less fre·
ular margins, the clinician should be able to deter quently in the palatal region, whether by mistake or
mine its feasibility during the diagnostic stage by due to carelessness. Violation of the biologic width
classifying the periodontal biotype and evaluating the generally causes inflammation of the circular fibers.
clinical situation (Figs 6-u to 6-14). even in areas not adjacent to the site of damage. ..
FIG 6-8 FIG 6-9
Fig 6-6 Absence of kerati � ized tiss � e around a � andibular right canine. � n this case. intrasulcular positioning of the finish l1ne is impossi
.
ble. F1gs 6 - 7to 6-9 Analysis of kerat1n1zed tissue 1n a pat10nt With a ceramic crown on the mmllary right central incisor. The periodontal bio
type is thick. wh1ch is evident under high magnification and espemlly in a lateral v1ew.
171
m
CHAPTER 6
.. An article by Kois9 has become a standard refer In a study by Tarnow et al.'0 the finish lines in two
ence for the study and analysis of the relationship be patients were positioned halfway between the bone
tween the bone crest and the gingival margin. Kois's crest and the gingival margin. The researchers noted
bone-sounding technique involves anesthetizing a gingival recession ranging between 0-4 and 1.2 mm
gingival area before inserting a thin periodontal probe after 2 weeks and 1.2 mm or more after 8 weeks.
to the bone crest. The buccal and interproximal mea These results demonstrate histologically that reces
surements thus obtained define the ridge type and sion phenomena were activated in the first 7 days;
its relationship to the gingiva. This procedure has the junctional epithelium and connective tissue then
been used to distinguish three types of gingiva-bone re-formed apical to the finish line. This study indi
crest structure.9 A normal crest, found in 85% of cates that the natural mechanisms that repair inva
patients, is defined as having probing depths of sive damage to the biologic width result in gingival
3 mm in buccal areas and 4-5 mm in interproximal recession, with all or its obvious functional and
areas. A high crest. found in 2% of patients, has esthetic drawbacks.
probing depths of less than 3 mm in both the buccal Although they never use the bone-sounding tech
and interproximal areas. A /ow crest, present in 13% nique, the authors of this text adhere to the Kois
of patients, has probing depths of greater than 3 mm classification9 of ridge type. By analyzing the clinical
in the buccal area and greater than 5 mm in the inter results or normal periodontal probing, intraoral radio
proximal regions. graphs, and clinical examination, a clinician can detect
Different gingiva-bone crest structures require dif many conditions, including gingival recession, insufi
ferent approaches to gingival retraction. With a high cient keratinized gingiva, incomplete tooth eruption,
ridge, the clinician will have difficulty inserting retrac and edentulous areas. Depending on the patient
tion cords and runs the risk of intruding on the bio ridge type, the authors adopt different materials and
logic width. With a low ridge and unstable periodon techniques. whenever possible, to perform periodon
tal tissue, gingival retraction can lead to gingival tal interventions aimed at restoring the proper bio
recession (Figs 6-15 and 6-16). logic width so as to allow for intracrevicular margins"
(Figs 6-17 to 6-30). .
6- 1 3
Fig 6-10 Collarless metal-ceramic crown. This restoration technique is often proposed in cases in which gingival tissue is
lack1ng and the restoration margin must be positioned supra- or juxtagingivally.
Figs 6-11 o 6- 14 Details of a restoratiOn !Figs 6 - l l and 6-121 and a natural tooth !Figs 6-13 and 6-141 1profile views were pho
_
tographed Without _
a flash). The anatomy of the g•ng1val sulcus and its relationship with the restoration is evident. Note the
appearance of the sulcus under the stereomicroscope. as well as the emergence profile of the crown and tooth. The frontal
v11ws illustrate the health of the gingival tissue for each.
171
179
CHAPTER 6
.. An article by Kois9 has become a standard refer In a study by Tarnow et al.'0 the finish lines in two
ence for the study and analysis of the relationship be patients were positioned halfway between the bone
tween the bone crest and the gingival margin. Kois's crest and the gingival margin. The researchers noted
bone-sounding technique involves anesthetizing a gingival recession ranging between 0-4 and 1.2 mm
gingival area before inserting a thin periodontal probe after 2 weeks and 1.2 mm or more after 8 weeks.
to the bone crest. The buccal and interproximal mea These results demonstrate histologically that reces
surements thus obtained define the ridge type and sion phenomena were activated in the first 7 days;
its relationship to the gingiva. This procedure has the junctional epithelium and connective tissue then
been used to distinguish three types of gingiva-bone re-formed apical to the finish line. This study indi
crest structure.9 A normal crest, found in 85% of cates that the natural mechanisms that repair inva
patients, is defined as having probing depths of sive damage to the biologic width result in gingival
3 mm in buccal areas and 4-5 mm in interproximal recession, with all or its obvious functional and
areas. A high crest. found in 2% of patients, has esthetic drawbacks.
probing depths of less than 3 mm in both the buccal Although they never use the bone-sounding tech
and interproximal areas. A /ow crest, present in 13% nique, the authors of this text adhere to the Kois
of patients, has probing depths of greater than 3 mm classification9 of ridge type. By analyzing the clinical
in the buccal area and greater than 5 mm in the inter results or normal periodontal probing, intraoral radio
proximal regions. graphs, and clinical examination, a clinician can detect
Different gingiva-bone crest structures require dif many conditions, including gingival recession, insufi
ferent approaches to gingival retraction. With a high cient keratinized gingiva, incomplete tooth eruption,
ridge, the clinician will have difficulty inserting retrac and edentulous areas. Depending on the patient
tion cords and runs the risk of intruding on the bio ridge type, the authors adopt different materials and
logic width. With a low ridge and unstable periodon techniques. whenever possible, to perform periodon
tal tissue, gingival retraction can lead to gingival tal interventions aimed at restoring the proper bio
recession (Figs 6-15 and 6-16). logic width so as to allow for intracrevicular margins"
(Figs 6-17 to 6-30). .
6- 1 3
Fig 6-10 Collarless metal-ceramic crown. This restoration technique is often proposed in cases in which gingival tissue is
lack1ng and the restoration margin must be positioned supra- or juxtagingivally.
Figs 6-11 o 6- 14 Details of a restoratiOn !Figs 6 - l l and 6-121 and a natural tooth !Figs 6-13 and 6-141 1profile views were pho
_
tographed Without _
a flash). The anatomy of the g•ng1val sulcus and its relationship with the restoration is evident. Note the
appearance of the sulcus under the stereomicroscope. as well as the emergence profile of the crown and tooth. The frontal
v11ws illustrate the health of the gingival tissue for each.
171
179
CHAPTER 6
E V A L U AT I O N 0 F P E R I O D O N TA L B I OT Y P E
Fig 6·17 Prov1s1onal restoration in place after removal of the metal-ceramic crowns The dental techniciiR created leteral 1nd untral
F1gs 6-lSand6-l6 Gingival recession w1th metal-ceramic restorations resulting from improper treatment of the gingiva. incisors with different shapes to accommodate uneven gingival contours. resulting in a lack of harmony and an unnatural appnrance. Fig
6-18 Residual tooth structure. Restoral1on w1ll require periodontal surgery. involving clinical crown lengthening 1nd formation of the cor
rect bone and gingival contours F1gs 6-19 o 6-11 Surgical crown lengthening A gingival flap was made with 1 paramarginal incision and
repositioned at the level of the bone crest. us1ng the measunng lip of a bur i H207 314 012. Komet). Two notches are made to mark the dis
tance created between the bone crest and the finish line Figs 6-22 and 6-13 Mattress-style vertical sutures anchored to the periosteu m .
lG
CHAPTER 6
E V A L U AT I O N 0 F P E R I O D O N TA L B I OT Y P E
Fig 6·17 Prov1s1onal restoration in place after removal of the metal-ceramic crowns The dental techniciiR created leteral 1nd untral
F1gs 6-lSand6-l6 Gingival recession w1th metal-ceramic restorations resulting from improper treatment of the gingiva. incisors with different shapes to accommodate uneven gingival contours. resulting in a lack of harmony and an unnatural appnrance. Fig
6-18 Residual tooth structure. Restoral1on w1ll require periodontal surgery. involving clinical crown lengthening 1nd formation of the cor
rect bone and gingival contours F1gs 6-19 o 6-11 Surgical crown lengthening A gingival flap was made with 1 paramarginal incision and
repositioned at the level of the bone crest. us1ng the measunng lip of a bur i H207 314 012. Komet). Two notches are made to mark the dis
tance created between the bone crest and the finish line Figs 6-22 and 6-13 Mattress-style vertical sutures anchored to the periosteu m .
lG
[l· I
Figs 6-24 and 6-25 Clinical case presenting with four metal-ceramic crowns lhal are incongruous in form and gingival contour. The palienl Figs 6-28 and 6-2g Surgical stage with an apically positioned gingival flap. The views show lhe new contours of remodeled bone and lhe treat
sought a new restoration because of significant gingival recession of I he central and lateral incisors. ment to lhe palatal area.
Figs 6-26 and 6-27 Presurgical views show1ng lhe residual Ieeth before and after loolh whitening with the walking bleach procedure. using Fig 6-30 Cornick"s - baslinf sutures.
sodium perborale and hydrogen peroxide.
112 18J
[l· I
Figs 6-24 and 6-25 Clinical case presenting with four metal-ceramic crowns lhal are incongruous in form and gingival contour. The palienl Figs 6-28 and 6-2g Surgical stage with an apically positioned gingival flap. The views show lhe new contours of remodeled bone and lhe treat
sought a new restoration because of significant gingival recession of I he central and lateral incisors. ment to lhe palatal area.
Figs 6-26 and 6-27 Presurgical views show1ng lhe residual Ieeth before and after loolh whitening with the walking bleach procedure. using Fig 6-30 Cornick"s - baslinf sutures.
sodium perborale and hydrogen peroxide.
112 18J
CHAPTER 6
.. G I N G IVAL RETRACTION minum sulfate, and ferrous sulfate and their various
combinations (Fig 6·38 to 6·40).
T h e need t o retract gingiva for taking impressions i s Surgical techniques involve rotary curettage or
A di rect relationship usually
universally acknowledged, »-t4 although clinicians electrosurgery to remove the epithelial layer of the
exists between a m i n i mum
disagree as to technique. The complexity of the pro· sulcular tissue.
horizontal displacement
cedure arises from a need to provide adequate hor· The use of any retraction system requires healthy and a significant undercut
izontal space for the impression materials. Laufer et periodontal tissue that has not been damaged or
6-3 1
at'S have determined that the horizontal space must innamed during tooth preparation. The selection of
be between 0.2 and 0-4 mm, so that when the re· a retraction technique depends on the operator's ex·
traction cord is removed, the clinician can compen· perience, the periodontal biotype, and, in the authors'
sate for the substantial undercut of the final prepa view, the principle of choosing the least invasive
ration (Figs 6-31 to 6·34). Gingival retraction during technique that will produce the most effective re·
any stage of restoration, no matter the technique, suits. Based on these criteria, mechanical or mechan·
may cause a lesion to form on the periodontal tis· icochemical methods can be used, but surgery,
sue.'6 Periodontal tissue with normal healing capac· whether with a rotating instrument or electric scalpel,
ity will repair itself.'7-'B should not be considered because of the clinical dif·
ficulties and the uncertainty of outcome.
Gingival retraction is divided into two stages,
Gingival retraction techniques
namely vertical and horizontal. During vertical de·
Techniques for gingival retraction are traditionally nection, the clinician can position and complete the
classiied as mechanical, mechanicochemical, and sur· finish line, while horizontal denection facilitates im·
gicat. Mechanical techniques are manifold and in· pression taking and the subsequent removal of the
elude the use of silk or cotton cords, silicone-based impression material.
substances, copper rings, and compressive displace· Traditionally, these two stages are accomplished
ment.'9 These techniques are sometimes insuficient through the use of a double retraction cord," along
for obtaining the required retraction for refining prep with a small-diameter thread to create vertical dis·
arations and taking impressions 20 In the authors' placement as well as a larger- diameter thread for
view, some of these methods can even be harmful horizontal denection. The larger-diameter thread is
(Figs 6·35 to 6-37). removed immediately before the application of the
Mechanicochemical techniques combine mechan· impression materials, whereas the small-diameter
ical and chemical interventions. The term often refers thread remains i n place during the impression. Clini
to the use of retraction cords impregnated with solu· cians must understand the characteristics of diferent
tions that have hemostatic or vasoconstricting retraction cords and their compatibility with the
effects, such as epinephrine, aluminum chloride, alu· impression materials. ..
Fig 6-31 Design far intact tooth structure beyond the finish line. which represents the largest undercut possible. in relation to
the quantity of material needed for the impression because of the need to keep horizontal retraction to a minimum and thus
make the positioning of the marg1n reliable. Much also depends on the type of tooth being prepared. because a triangular
tooth that tapers toward the root w1ll have greater undercut than a square tooth with a very large root. Figs 6-32 and 6-33 Tooth
prepared for a ceramic complete crown The limited space between the epithelium and the finish line can be seen. In this sit
uation it would be futile to allempt to take an impress1on without a retraction cord in place. Fig 6-4 Silvered master cast
_ and the area
reveals the f1n1sh line of 1ntact tooth structure beyond it.
14
CHAPTER 6
.. G I N G IVAL RETRACTION minum sulfate, and ferrous sulfate and their various
combinations (Fig 6·38 to 6·40).
T h e need t o retract gingiva for taking impressions i s Surgical techniques involve rotary curettage or
A di rect relationship usually
universally acknowledged, »-t4 although clinicians electrosurgery to remove the epithelial layer of the
exists between a m i n i mum
disagree as to technique. The complexity of the pro· sulcular tissue.
horizontal displacement
cedure arises from a need to provide adequate hor· The use of any retraction system requires healthy and a significant undercut
izontal space for the impression materials. Laufer et periodontal tissue that has not been damaged or
6-3 1
at'S have determined that the horizontal space must innamed during tooth preparation. The selection of
be between 0.2 and 0-4 mm, so that when the re· a retraction technique depends on the operator's ex·
traction cord is removed, the clinician can compen· perience, the periodontal biotype, and, in the authors'
sate for the substantial undercut of the final prepa view, the principle of choosing the least invasive
ration (Figs 6-31 to 6·34). Gingival retraction during technique that will produce the most effective re·
any stage of restoration, no matter the technique, suits. Based on these criteria, mechanical or mechan·
may cause a lesion to form on the periodontal tis· icochemical methods can be used, but surgery,
sue.'6 Periodontal tissue with normal healing capac· whether with a rotating instrument or electric scalpel,
ity will repair itself.'7-'B should not be considered because of the clinical dif·
ficulties and the uncertainty of outcome.
Gingival retraction is divided into two stages,
Gingival retraction techniques
namely vertical and horizontal. During vertical de·
Techniques for gingival retraction are traditionally nection, the clinician can position and complete the
classiied as mechanical, mechanicochemical, and sur· finish line, while horizontal denection facilitates im·
gicat. Mechanical techniques are manifold and in· pression taking and the subsequent removal of the
elude the use of silk or cotton cords, silicone-based impression material.
substances, copper rings, and compressive displace· Traditionally, these two stages are accomplished
ment.'9 These techniques are sometimes insuficient through the use of a double retraction cord," along
for obtaining the required retraction for refining prep with a small-diameter thread to create vertical dis·
arations and taking impressions 20 In the authors' placement as well as a larger- diameter thread for
view, some of these methods can even be harmful horizontal denection. The larger-diameter thread is
(Figs 6·35 to 6-37). removed immediately before the application of the
Mechanicochemical techniques combine mechan· impression materials, whereas the small-diameter
ical and chemical interventions. The term often refers thread remains i n place during the impression. Clini
to the use of retraction cords impregnated with solu· cians must understand the characteristics of diferent
tions that have hemostatic or vasoconstricting retraction cords and their compatibility with the
effects, such as epinephrine, aluminum chloride, alu· impression materials. ..
Fig 6-31 Design far intact tooth structure beyond the finish line. which represents the largest undercut possible. in relation to
the quantity of material needed for the impression because of the need to keep horizontal retraction to a minimum and thus
make the positioning of the marg1n reliable. Much also depends on the type of tooth being prepared. because a triangular
tooth that tapers toward the root w1ll have greater undercut than a square tooth with a very large root. Figs 6-32 and 6-33 Tooth
prepared for a ceramic complete crown The limited space between the epithelium and the finish line can be seen. In this sit
uation it would be futile to allempt to take an impress1on without a retraction cord in place. Fig 6-4 Silvered master cast
_ and the area
reveals the f1n1sh line of 1ntact tooth structure beyond it.
14
chnical Considerations for Soft Tissue Retraction
f1g a 3S N1tural preparad tooth follow�ng removal of th1 frtcturod porcol11n lam1nato Yeneer Figs 6-39 and 6-0 Cementation phase of the restoratiOn, w1th the veneer 1n place after removal of rubber dam Note the perfect volumetm pro
portiOns and the marginal adaptatiOn
f1g a 3a Following proper ra-propor1t1on of th1 tooth, 1 non impregnated silk cord 11 pos11ioned 1n tho sulcus for m1n1mal vertical deflection
r1g 8-7 In 1n occluul vltw the cord c1nnot be sun around th1 1nt1r1 buccal aspect, a 11gn of insuff1c1enl deflection
f1g & 31 S1m1 tooth 1fler the non1mpregn1ted 11lk cord hu bun removed and repl1ced w1th a br11ded cord Impregnated w1th alum1num sui
fall, providing grntor vert1c1l and homontal g1ng1v11 defl1clion
Ill 117
chnical Considerations for Soft Tissue Retraction
f1g a 3S N1tural preparad tooth follow�ng removal of th1 frtcturod porcol11n lam1nato Yeneer Figs 6-39 and 6-0 Cementation phase of the restoratiOn, w1th the veneer 1n place after removal of rubber dam Note the perfect volumetm pro
portiOns and the marginal adaptatiOn
f1g a 3a Following proper ra-propor1t1on of th1 tooth, 1 non impregnated silk cord 11 pos11ioned 1n tho sulcus for m1n1mal vertical deflection
r1g 8-7 In 1n occluul vltw the cord c1nnot be sun around th1 1nt1r1 buccal aspect, a 11gn of insuff1c1enl deflection
f1g & 31 S1m1 tooth 1fler the non1mpregn1ted 11lk cord hu bun removed and repl1ced w1th a br11ded cord Impregnated w1th alum1num sui
fall, providing grntor vert1c1l and homontal g1ng1v11 defl1clion
Ill 117
CHAPTER 6
Technical Considerations for Sot Tissue Retraction
.. Retraction cords break, hold the chemical solutions 2.5 times longer
than other kinds of cords, and do not get tangled in
In prosthodontics, retraction cords are the most rotating diamond burs during preparation. However,
common method used to displace tissue for impres· they are easily cut during preparation and, because
sion taking, and many different types of cords and they are more easily compressed, offer less gingival
chemical solutions are available (Fig 6·41). Most retraction.
cords are made of various textile blends of wool,
silk, cotton, and synthetic fibers, which are twisted,
I m pregnating chem icals
braided, or knitted together'9 (Fig 6-42). Cords also
can be distinguished as either soft or compact. Sot For mechanicochemical techniques, retraction cords
cords are easy to position and have a high capacity are i mpregnated with chemical solutions that aug
for absorbing gingival fluids or chemical solutions, ment the effect of retraction and hemostasis. How
but they can break easily during positioning and ever, animal studies using dogs21 have shown that
removal and disintegrate when in contact with re· chemical solutions cause a certain amount of inflam
traction fluids. Compact cords provide better hori· mation of the connective tissue. Among the most
zontal displacement, exhibit minimal degeneration frequently used solutions are epinephrine; various
from retraction fluids, and are less prone to break astringents, such as aluminum chloride, aluminum
ing, but they are difficult to position and absorb min sulfate, and ferrous sulfate; and combinations of
imal gingival or retraction luids. these compounds.22 Fig 6-41 Different types of retraction cord. There are many types of cords and Impregnating substances.
Twisted cords are the oldest type of cord used Epinephrine is frequently used because it offers Fig 6-42 Basic types ol retraction cord: (left to righ) braided. twisted. and knitted.
Fig 6-43 Result of taking an impression after using a retraction cord impregnated with aluminum chloride. The impression material. in this
in dentistry; these are composed of two or three excellent vasoconstriction, provides considerable tis
case polyether. cannot polymerize correctly in the presence of aluminum chloride. The same situation applies to aluminum sulfate and
threads twisted together. Twisted cords are easy to sue retraction, and results in minimal postoperative polyvinyl siloxane.
insert, and larger cords can be separated into two tissue loss.'B One study,'J however, found no signif
smaller ones. However, the threads come apart eas icant difference compared with aluminum sulfate.
ily during positioning and can get tangled in the Epinephrine should never be used in patients whose
rotating bur during preparation. gingiva has been damaged during preparation or for
The braided cords are woven so tightly that it is patients with hyperthyroid conditions, cardiovascular
impossible to separate the threads. These cords are pathologies, or hypersensitivity. The latter conditions . However, it can be used on damaged tissues with necessary to carefully clean the surfa ce of the cord
vey stable, remain intact during positioning, do not may lead to cardiovascular reactions, such as an only moderate tissue loss after healing. with cotton pellets and water spray to reduce or
get tangled or torn by rotating diamond burs, and i ncrease in blood pressure, tachycardia, accelerated The impregnating solutions can inhibit the poly eliminate the polymerization interference.
come in two varieties: solid core and hollow core. respiration, or headache. merization of impression material when they come in Aluminum sulate ofers good gingival retraction
Cords with a solid core exhibit greater volume and Aluminum chloride is a commonly used astringent contact; a similar phenomena has been found when and eicient working time. Some authors27 believe
more horizontal retraction, but they are stiffer and that causes no adverse systemic effects and only a latex gloves are used with polyvinyl siloxanes.'6 this chemical is toxic to tissues and, because of the
more difficult to inset. Cords with hollow cores have few undesired localized effects. 24 It is usually found Aluminum chloride is compatible with polyvinyl silox sulfur, can interfere with the polymerization of poly
greater flexibility and are easier to position, but they marketed as a 14% solution. The hemostasis and anes, but it inhibits the reaction of the polyether vinyl siloxanes'8 i f the cord is not rinsed thoroughly
are less voluminous and exhibit less horizontal dis retraction that are provided by aluminum chloride chains, and if they remain in contact, the impression before impression. On the other hand, aluminum sul
placement. are inferior to those of epinephrine; moreover, if material loses its contours and detail and will appear fate shows excellent compatibility with polyethers in
The knitted cords are knitted together without a used at high concentrations, this chemical can cause melted (Fig 6-43). Many clinicians continue to use general, and it is recommended for use with these
central thread. They are easily compressed, do not significant postoperative paramarginal tissue loss.'S . aluminum chloride as a hemostatic agent, making it impression materials. ..
11
CHAPTER 6
Technical Considerations for Sot Tissue Retraction
.. Retraction cords break, hold the chemical solutions 2.5 times longer
than other kinds of cords, and do not get tangled in
In prosthodontics, retraction cords are the most rotating diamond burs during preparation. However,
common method used to displace tissue for impres· they are easily cut during preparation and, because
sion taking, and many different types of cords and they are more easily compressed, offer less gingival
chemical solutions are available (Fig 6·41). Most retraction.
cords are made of various textile blends of wool,
silk, cotton, and synthetic fibers, which are twisted,
I m pregnating chem icals
braided, or knitted together'9 (Fig 6-42). Cords also
can be distinguished as either soft or compact. Sot For mechanicochemical techniques, retraction cords
cords are easy to position and have a high capacity are i mpregnated with chemical solutions that aug
for absorbing gingival fluids or chemical solutions, ment the effect of retraction and hemostasis. How
but they can break easily during positioning and ever, animal studies using dogs21 have shown that
removal and disintegrate when in contact with re· chemical solutions cause a certain amount of inflam
traction fluids. Compact cords provide better hori· mation of the connective tissue. Among the most
zontal displacement, exhibit minimal degeneration frequently used solutions are epinephrine; various
from retraction fluids, and are less prone to break astringents, such as aluminum chloride, aluminum
ing, but they are difficult to position and absorb min sulfate, and ferrous sulfate; and combinations of
imal gingival or retraction luids. these compounds.22 Fig 6-41 Different types of retraction cord. There are many types of cords and Impregnating substances.
Twisted cords are the oldest type of cord used Epinephrine is frequently used because it offers Fig 6-42 Basic types ol retraction cord: (left to righ) braided. twisted. and knitted.
Fig 6-43 Result of taking an impression after using a retraction cord impregnated with aluminum chloride. The impression material. in this
in dentistry; these are composed of two or three excellent vasoconstriction, provides considerable tis
case polyether. cannot polymerize correctly in the presence of aluminum chloride. The same situation applies to aluminum sulfate and
threads twisted together. Twisted cords are easy to sue retraction, and results in minimal postoperative polyvinyl siloxane.
insert, and larger cords can be separated into two tissue loss.'B One study,'J however, found no signif
smaller ones. However, the threads come apart eas icant difference compared with aluminum sulfate.
ily during positioning and can get tangled in the Epinephrine should never be used in patients whose
rotating bur during preparation. gingiva has been damaged during preparation or for
The braided cords are woven so tightly that it is patients with hyperthyroid conditions, cardiovascular
impossible to separate the threads. These cords are pathologies, or hypersensitivity. The latter conditions . However, it can be used on damaged tissues with necessary to carefully clean the surfa ce of the cord
vey stable, remain intact during positioning, do not may lead to cardiovascular reactions, such as an only moderate tissue loss after healing. with cotton pellets and water spray to reduce or
get tangled or torn by rotating diamond burs, and i ncrease in blood pressure, tachycardia, accelerated The impregnating solutions can inhibit the poly eliminate the polymerization interference.
come in two varieties: solid core and hollow core. respiration, or headache. merization of impression material when they come in Aluminum sulate ofers good gingival retraction
Cords with a solid core exhibit greater volume and Aluminum chloride is a commonly used astringent contact; a similar phenomena has been found when and eicient working time. Some authors27 believe
more horizontal retraction, but they are stiffer and that causes no adverse systemic effects and only a latex gloves are used with polyvinyl siloxanes.'6 this chemical is toxic to tissues and, because of the
more difficult to inset. Cords with hollow cores have few undesired localized effects. 24 It is usually found Aluminum chloride is compatible with polyvinyl silox sulfur, can interfere with the polymerization of poly
greater flexibility and are easier to position, but they marketed as a 14% solution. The hemostasis and anes, but it inhibits the reaction of the polyether vinyl siloxanes'8 i f the cord is not rinsed thoroughly
are less voluminous and exhibit less horizontal dis retraction that are provided by aluminum chloride chains, and if they remain in contact, the impression before impression. On the other hand, aluminum sul
placement. are inferior to those of epinephrine; moreover, if material loses its contours and detail and will appear fate shows excellent compatibility with polyethers in
The knitted cords are knitted together without a used at high concentrations, this chemical can cause melted (Fig 6-43). Many clinicians continue to use general, and it is recommended for use with these
central thread. They are easily compressed, do not significant postoperative paramarginal tissue loss.'S . aluminum chloride as a hemostatic agent, making it impression materials. ..
11
CHAPTER 6
. Ferrous sulfate is commonly used as an astrin ment with a thickness to suit the cord type (twisted,
gent because of its excellent hemostasis and negli braided, or knitted). In the authors' view, cord place
gible tissue loss. However, this chemical provides ment can be accomplished using a composite spat
minimal retraction and stains the gingival tissues. ula or other tool and does not require the purchase
The precipitate that forms on the cord is difficult to of expensive, specially designed instruments.
eliminate before taking impressions, and since fer Using an instrument compatible with the cord
rous sulfate is incompatible with polyethers, clini type, the clinician begins by gently inseting the cord
cians must use hydrocolloidal impression material. in the interproximal zone. The greater quantity of
In the authors' view, the use of this chemical and its gingival tissue found in the interproximal zone
associated impression technique are obsolete. makes it more favorable than the buccal area for
Various combinations of astringents can also be starting cord placement. The cord is inserted using
used for retraction. The combination of aluminum a single spatula or two spatulas at the same time
sulfate and aluminum chloride seems to provide bet (the bimanual technique) (Figs 6-44 to 6-47). The
ter results than either of the two used in combina clinician must not push too hard, as this could result
tion with epinephrine. in placing the cord too deep. After the first part of
the cord is positioned, the clinician must work along
the buccal zone. toward the initial point of insertion.
R ETRACTION PROCEDURES
If the clinician begins working away from the initial
point of insertion, the portion of the cord already in
Mechanical a n d mechanicochemical
place tends to shift (Fig 6-48). After inserting the
techniq ues
cord along the buccal zone, the ends should be
Although the cord-positioning procedure is the same inserted in the palatal area, where overlaps are bet
regardless of cord type or technique, retraction cords ter tolerated.
can be used in single-cord, selective double-cord, or Some authors29 recommend that. when using the
double-cord approaches. single-cord technique, the cord be removed immedi
The single-cord technique generally requires a ately before taking the impression. This technique,
cord of the smallest diameter (no. ooo or oo). For however, should be avoided, because once the cord
cord insertion, the clinician uses a manual instru- is removed, the sulcus tends to close immediately, .
X
Figs 6-4 and 6-45 Placement of retraction cord, preVIOusly cut to the size of the tooth. Insertion beg�ns '" the �nterprox1mal
area and leaves the two loose ends to be overlapped '" the palatal area.
Fig 6-46 Bimanual technique. The cliniCian may use two Instruments simultaneously. one to hold lhe retract1on cord in posi
tion and the second to insert 1t 6-4BA 6-488
Fig 6-47 Effects of g�ng1val retraction. Before insert1on of the retraction cord. the finiSh l1ne was at the same level as the gin
gival marg1n
Fig 6-48 insertlon technique Working away from the initial po1nt of Insertion /a) i s ineffective The cliniCian must work toward
the IRII1al po1nt of insert1on fbi. starling at a po1nt a good diStance from the Initial point
110
lfl
CHAPTER 6
. Ferrous sulfate is commonly used as an astrin ment with a thickness to suit the cord type (twisted,
gent because of its excellent hemostasis and negli braided, or knitted). In the authors' view, cord place
gible tissue loss. However, this chemical provides ment can be accomplished using a composite spat
minimal retraction and stains the gingival tissues. ula or other tool and does not require the purchase
The precipitate that forms on the cord is difficult to of expensive, specially designed instruments.
eliminate before taking impressions, and since fer Using an instrument compatible with the cord
rous sulfate is incompatible with polyethers, clini type, the clinician begins by gently inseting the cord
cians must use hydrocolloidal impression material. in the interproximal zone. The greater quantity of
In the authors' view, the use of this chemical and its gingival tissue found in the interproximal zone
associated impression technique are obsolete. makes it more favorable than the buccal area for
Various combinations of astringents can also be starting cord placement. The cord is inserted using
used for retraction. The combination of aluminum a single spatula or two spatulas at the same time
sulfate and aluminum chloride seems to provide bet (the bimanual technique) (Figs 6-44 to 6-47). The
ter results than either of the two used in combina clinician must not push too hard, as this could result
tion with epinephrine. in placing the cord too deep. After the first part of
the cord is positioned, the clinician must work along
the buccal zone. toward the initial point of insertion.
R ETRACTION PROCEDURES
If the clinician begins working away from the initial
point of insertion, the portion of the cord already in
Mechanical a n d mechanicochemical
place tends to shift (Fig 6-48). After inserting the
techniq ues
cord along the buccal zone, the ends should be
Although the cord-positioning procedure is the same inserted in the palatal area, where overlaps are bet
regardless of cord type or technique, retraction cords ter tolerated.
can be used in single-cord, selective double-cord, or Some authors29 recommend that. when using the
double-cord approaches. single-cord technique, the cord be removed immedi
The single-cord technique generally requires a ately before taking the impression. This technique,
cord of the smallest diameter (no. ooo or oo). For however, should be avoided, because once the cord
cord insertion, the clinician uses a manual instru- is removed, the sulcus tends to close immediately, .
X
Figs 6-4 and 6-45 Placement of retraction cord, preVIOusly cut to the size of the tooth. Insertion beg�ns '" the �nterprox1mal
area and leaves the two loose ends to be overlapped '" the palatal area.
Fig 6-46 Bimanual technique. The cliniCian may use two Instruments simultaneously. one to hold lhe retract1on cord in posi
tion and the second to insert 1t 6-4BA 6-488
Fig 6-47 Effects of g�ng1val retraction. Before insert1on of the retraction cord. the finiSh l1ne was at the same level as the gin
gival marg1n
Fig 6-48 insertlon technique Working away from the initial po1nt of Insertion /a) i s ineffective The cliniCian must work toward
the IRII1al po1nt of insert1on fbi. starling at a po1nt a good diStance from the Initial point
110
lfl
CHAPTER 6
. preventing penetration of the impression material. drawback of using a second cord is the inevitable . deflection using a compound of kaolin and aluminum sive contact of the electrode with the tissues even at
Cord removal also can result in bleeding. The clini compression and apical repositioning of the first chloride (Expasyl, Pierre Rolland) which has a d ilat low frequencyB can cause high temperatures from
cian must keep the cord in place throughout the cord, which makes cord positioning difficult to con· ing effect (Figs 6-64 to 6-66). The product comes in lateral heat, which also can result in tissue necrosis.
operative stages, from repositioning and completing trol and healing from the gingival displacement convenient capsules and can be injected while it is For this reason, researchers and m a n u facturers
the finish line to taking the impression. unpredictable. still malleable directly into the sulcus with a small have developed electrosurgery instruments that use
The cord must retract the gingiva enough to ex However, i n the authors' experience, a second re gauge syringe. Expasyl expands and hardens upon small-diameter electrodes. These instruments, which
pose a portion of the unprepared tooth lying beyond traction cord must never be used during tooth prepar contact with the fluids in the sulcus. Because of the have a filtered current that produces less lateral
the finish line, without i nterference from the soft tis ation and positioning of the finish line because of aluminum chloride, the clinician must rinse the area heat, are more appropriately called radioscalpels and
sue. If the gingiva is not retracted suficiently, the the serious risk of gingival recession. Thus, choosing copiously before taking an im pression, especially if their technique, radiosurgery. A radioscalpel works
impression material will not properly record the fin a technique depends on which instruments are used polyether material is being used. Expasyl is very with ultrahigh-frequency radio waves to make a
ish line preparation and intact tooth (Figs 6-49 to for the finish line positioning and which impression effective when used in combination with a single clean cut without necrosing the gingival tissues. In
6-53). materials are used. cord, but in the authors' opinion its use alone pro addition to high frequency (27 MHz) and a small
The selective double-cord technique involves insert During tooth preparation, the clinician must never vides insufficient retraction for taking an impression. diameter electrode, an important distinction between
ing small pieces of cord of equal or greater diameter lose the points of reference, especially of the gingi Moreover, if Expasyl is used without a retraction the radioscalpel and the electroscalpel concerns the
(no. o, 1, or 2) in the interproximal area directly over val margin, always proceeding according to the stages cord, the clinician cannot position a subgingival absence or presence of a grounding plate; the pres
the irst cord, to further displace the papillae (Figs outlined in chapter 5- When using rotating instru restoration margin without damaging the gingiva; it ence of a large grounding plate causes anxiety i n
6-54 to 6-6o). This method of selective horizontal ments for primary tooth reduction, the clinician must does not provide the same amount of space that can some patients. For these reasons, t h e use of a radio
displacement facilitates impression taking without avoid accidentally touching or damaging the gingiva be obtained by using a cord. scalpel (Odontosurge, Odonto-Wave) is recommended.
involving the delicate buccal tissues. The pieces of in order to keep the tissue intact and free of bleed The clinician must a lways maintain visibility of the
cord must be removed immediately before taking the ing. Above all, the retraction cords must be placed, cut, which can be achieved by using magnifying instru
Surg ical tech n i q ues
impression. no matter how temporarily, only after the guide ments such as a stereomicroscope in indirect vision.
The double-cord technique requires the insertion groove and finish line position have been defined. Sometimes, after vertical retraction with a single cord The radioscalpel can be used only in the interproxi
of a second cord of equal or greater diameter (no. o, If the clinician repositions the finish line with and the completing of the finish line with oscillating mal and palatal areas, and never in the buccal areas
1, or 2) directly over the first cord to obtain the hor oscillating instruments to minimize gingival damage, instruments, gingiva may still block access for the (Figs 6-68 to 6-71). When it has been used to remove
izontal retraction for the entire ci rcumference of the and if a continuous jet of water and air is used to impression material. I n such cases, the clinician may small bits of excess tissue, the point must be cleaned
prepared tooth1 2 ·3° (Figs 6-61 to 6-63). The second prevent overheating, the ideal horizontal displace need to remove gingival tissue using a surgical tech after each cut, both with a gauze pad soaked in alco
cord is removed just before the impression is taken, ment can be obtained mechanically. Impression mate nique (Fig 6-67). The traditional surgical procedure is hol and with a medium-grit refinishing disk.
while the first cord is left in place. In the first 20 sec rial can subsequently be injected in the sulcus with electrosurgery, which uses high-frequency waves to The authors believe the radioscalpel must be
onds after cord removal, the horizontal displacement out requiring a second retraction cord. If, after repo induce an electric current that cuts the gingival tis used only in combination with a retraction cord and
of the soft tissue is reduced by 35%, and in the sub· sitioning and completing the finish line with round sue and coagulates the wounds. Most electroscalpels is appropriate only for removing limited quantities of
sequent 20 seconds, another 18% of the displacement ed chisels, the first retraction cord (which was posi have two main components: a working point that is gingival tissue. Clinicians are strongly discouraged
space is lostY The speed at which the impression tioned 0.2 or 0.3 mm apical to the finish line) is not an electrode and a metal dispersion box to ground from using the electroscalpel or the radioscalpel as
material is inserted after the second retraction cord visible, the clinician may need additional horizontal the current with a frequency of about 3 MHz.3' the sole means of retraction because it is i mpossible
is removed is therefore critical. displacement. Localized displacement can be accom The greatest d rawback to using electrosurgey is to adequately control the depth of the cut.
Selecting a retraction technique depends on vari plished manually by retracting the gingival tissue the risk of producing high temperatures. Temperature
ous clinical factors and the type of cord used. For with the spatula used to position the cords im control requires using the electrical current at the
A D D ITIONAL G U I D E LI N ES
instance, the clinician would be well advised to use mediately prior to inserting the impression material. correct intensity; if it is too high, the electrode can
the double-cord technique for a patient with thick When the gingiva obscures the retraction cord in carbonize the tissue, whereas insuficient intensity In clinical practice, diferent types of retraction cord
periodontal tissue and/or slight inflammation. The several areas, the clinician can complete horizontal .. will cause the tissue to adhere to the electrode. Exces- are used depending on the periodontal biotype, the ..
2
193
CHAPTER 6
. preventing penetration of the impression material. drawback of using a second cord is the inevitable . deflection using a compound of kaolin and aluminum sive contact of the electrode with the tissues even at
Cord removal also can result in bleeding. The clini compression and apical repositioning of the first chloride (Expasyl, Pierre Rolland) which has a d ilat low frequencyB can cause high temperatures from
cian must keep the cord in place throughout the cord, which makes cord positioning difficult to con· ing effect (Figs 6-64 to 6-66). The product comes in lateral heat, which also can result in tissue necrosis.
operative stages, from repositioning and completing trol and healing from the gingival displacement convenient capsules and can be injected while it is For this reason, researchers and m a n u facturers
the finish line to taking the impression. unpredictable. still malleable directly into the sulcus with a small have developed electrosurgery instruments that use
The cord must retract the gingiva enough to ex However, i n the authors' experience, a second re gauge syringe. Expasyl expands and hardens upon small-diameter electrodes. These instruments, which
pose a portion of the unprepared tooth lying beyond traction cord must never be used during tooth prepar contact with the fluids in the sulcus. Because of the have a filtered current that produces less lateral
the finish line, without i nterference from the soft tis ation and positioning of the finish line because of aluminum chloride, the clinician must rinse the area heat, are more appropriately called radioscalpels and
sue. If the gingiva is not retracted suficiently, the the serious risk of gingival recession. Thus, choosing copiously before taking an im pression, especially if their technique, radiosurgery. A radioscalpel works
impression material will not properly record the fin a technique depends on which instruments are used polyether material is being used. Expasyl is very with ultrahigh-frequency radio waves to make a
ish line preparation and intact tooth (Figs 6-49 to for the finish line positioning and which impression effective when used in combination with a single clean cut without necrosing the gingival tissues. In
6-53). materials are used. cord, but in the authors' opinion its use alone pro addition to high frequency (27 MHz) and a small
The selective double-cord technique involves insert During tooth preparation, the clinician must never vides insufficient retraction for taking an impression. diameter electrode, an important distinction between
ing small pieces of cord of equal or greater diameter lose the points of reference, especially of the gingi Moreover, if Expasyl is used without a retraction the radioscalpel and the electroscalpel concerns the
(no. o, 1, or 2) in the interproximal area directly over val margin, always proceeding according to the stages cord, the clinician cannot position a subgingival absence or presence of a grounding plate; the pres
the irst cord, to further displace the papillae (Figs outlined in chapter 5- When using rotating instru restoration margin without damaging the gingiva; it ence of a large grounding plate causes anxiety i n
6-54 to 6-6o). This method of selective horizontal ments for primary tooth reduction, the clinician must does not provide the same amount of space that can some patients. For these reasons, t h e use of a radio
displacement facilitates impression taking without avoid accidentally touching or damaging the gingiva be obtained by using a cord. scalpel (Odontosurge, Odonto-Wave) is recommended.
involving the delicate buccal tissues. The pieces of in order to keep the tissue intact and free of bleed The clinician must a lways maintain visibility of the
cord must be removed immediately before taking the ing. Above all, the retraction cords must be placed, cut, which can be achieved by using magnifying instru
Surg ical tech n i q ues
impression. no matter how temporarily, only after the guide ments such as a stereomicroscope in indirect vision.
The double-cord technique requires the insertion groove and finish line position have been defined. Sometimes, after vertical retraction with a single cord The radioscalpel can be used only in the interproxi
of a second cord of equal or greater diameter (no. o, If the clinician repositions the finish line with and the completing of the finish line with oscillating mal and palatal areas, and never in the buccal areas
1, or 2) directly over the first cord to obtain the hor oscillating instruments to minimize gingival damage, instruments, gingiva may still block access for the (Figs 6-68 to 6-71). When it has been used to remove
izontal retraction for the entire ci rcumference of the and if a continuous jet of water and air is used to impression material. I n such cases, the clinician may small bits of excess tissue, the point must be cleaned
prepared tooth1 2 ·3° (Figs 6-61 to 6-63). The second prevent overheating, the ideal horizontal displace need to remove gingival tissue using a surgical tech after each cut, both with a gauze pad soaked in alco
cord is removed just before the impression is taken, ment can be obtained mechanically. Impression mate nique (Fig 6-67). The traditional surgical procedure is hol and with a medium-grit refinishing disk.
while the first cord is left in place. In the first 20 sec rial can subsequently be injected in the sulcus with electrosurgery, which uses high-frequency waves to The authors believe the radioscalpel must be
onds after cord removal, the horizontal displacement out requiring a second retraction cord. If, after repo induce an electric current that cuts the gingival tis used only in combination with a retraction cord and
of the soft tissue is reduced by 35%, and in the sub· sitioning and completing the finish line with round sue and coagulates the wounds. Most electroscalpels is appropriate only for removing limited quantities of
sequent 20 seconds, another 18% of the displacement ed chisels, the first retraction cord (which was posi have two main components: a working point that is gingival tissue. Clinicians are strongly discouraged
space is lostY The speed at which the impression tioned 0.2 or 0.3 mm apical to the finish line) is not an electrode and a metal dispersion box to ground from using the electroscalpel or the radioscalpel as
material is inserted after the second retraction cord visible, the clinician may need additional horizontal the current with a frequency of about 3 MHz.3' the sole means of retraction because it is i mpossible
is removed is therefore critical. displacement. Localized displacement can be accom The greatest d rawback to using electrosurgey is to adequately control the depth of the cut.
Selecting a retraction technique depends on vari plished manually by retracting the gingival tissue the risk of producing high temperatures. Temperature
ous clinical factors and the type of cord used. For with the spatula used to position the cords im control requires using the electrical current at the
A D D ITIONAL G U I D E LI N ES
instance, the clinician would be well advised to use mediately prior to inserting the impression material. correct intensity; if it is too high, the electrode can
the double-cord technique for a patient with thick When the gingiva obscures the retraction cord in carbonize the tissue, whereas insuficient intensity In clinical practice, diferent types of retraction cord
periodontal tissue and/or slight inflammation. The several areas, the clinician can complete horizontal .. will cause the tissue to adhere to the electrode. Exces- are used depending on the periodontal biotype, the ..
2
193
CHAPTtR 6
6-50
Figs 6-4g and 6-50 Distance between the finish line and the vertical retraction cord. a s well as the relationship with the paramarginal tissues. Fig 6-51 In the occlusal view. the retraction cords are visible after the finish line has been completed. There is no evidence of bleeding or
as viewed through the microscope. damaged soft tissue.
Figs 6-52 and 6-53 Removal of a metal crown from a vital tooth. After the tooth has been re-prepared. the retraction cord is perfectly visible
immediately before the impression is taken.
194 195
CHAPTtR 6
6-50
Figs 6-4g and 6-50 Distance between the finish line and the vertical retraction cord. a s well as the relationship with the paramarginal tissues. Fig 6-51 In the occlusal view. the retraction cords are visible after the finish line has been completed. There is no evidence of bleeding or
as viewed through the microscope. damaged soft tissue.
Figs 6-52 and 6-53 Removal of a metal crown from a vital tooth. After the tooth has been re-prepared. the retraction cord is perfectly visible
immediately before the impression is taken.
194 195
Fig 6-54 Occlusal view of a loath after a single retraction cord has been positioned. Gingiva obscures the cord around a significant part of
the tooth. Figs 6-55 and 6-56 Selective double-cord technique. Portions of cord are inserted in the areas where gingiva requires additional
retraction. The pieces of cord are removed immediately prior to laking lhe impression. Fig 6-57 Impression of the tooth. Figs 6-58 to 6-60
Ceramic crown with a pressed ceramic core offers high resistance. great precision. and excellent esthetics. Figs 6-61 and 6-62 Double- cord
technique. Note lhe lwo loose ends provided for fast removal immediately before insertion of the impression material into the sulcus. Fig
6-63 Impression accurately records lhe finish line. The thickness of the material at the margin of the impression indi cates the horizontal
displacement created by the double cords. Figs 6-64 to 6-66 Expansion material in the syringe and cartridge with single-use gauge to insert
material direclly mto the sulcus. Expasyt. a combination of kaolin and aluminum chloride. provides good horizontal retraction. is slightly
hemostatic. and works optimally in combination with a single vertical retraction cord. In the authors experien ce. Expasyl is useful i n cases
lacking vertical retraction. such as those showing excess or slightly damaged tissue after the insertion of the first cord.
Fig 6-54 Occlusal view of a loath after a single retraction cord has been positioned. Gingiva obscures the cord around a significant part of
the tooth. Figs 6-55 and 6-56 Selective double-cord technique. Portions of cord are inserted in the areas where gingiva requires additional
retraction. The pieces of cord are removed immediately prior to laking lhe impression. Fig 6-57 Impression of the tooth. Figs 6-58 to 6-60
Ceramic crown with a pressed ceramic core offers high resistance. great precision. and excellent esthetics. Figs 6-61 and 6-62 Double- cord
technique. Note lhe lwo loose ends provided for fast removal immediately before insertion of the impression material into the sulcus. Fig
6-63 Impression accurately records lhe finish line. The thickness of the material at the margin of the impression indi cates the horizontal
displacement created by the double cords. Figs 6-64 to 6-66 Expansion material in the syringe and cartridge with single-use gauge to insert
material direclly mto the sulcus. Expasyt. a combination of kaolin and aluminum chloride. provides good horizontal retraction. is slightly
hemostatic. and works optimally in combination with a single vertical retraction cord. In the authors experien ce. Expasyl is useful i n cases
lacking vertical retraction. such as those showing excess or slightly damaged tissue after the insertion of the first cord.
M I N I M A L H O R I Z O N TA L D E F L E C T I O N
Fig 6-67 Occlusal view of partially obscured retraction cords around two maxillary right t .. th after repositioning and com
pleting the finish line. The radiosurgery technique removes minimal amounts of gingival tissue with a radioscalpel to leave
the finish line visible and ready for impression material. Fig 6-68 Point of the radioscalpet used to remove excess tissue. A
plastic (noncondu ctive) mirror and a medium-grit disk soaked in alcohol are also used in radiosurgery. Figs 6-69 and 6-70 Cut
progression of the working point. as s"n through the stereomicroscope in indirect vision. Radiosurgery is never used on the
buccal aspect of the tooth. The small tip of a high-frequency radioscalpel is very precise. and the presence of the first
retraction cord helps the clinician to avoid errors of depth or direction. Fig 6-71 View of same tooth after removal of a thin
band of gingival tissue that obscured the retraction cord. The sulcus shows no signs of bl .. ding after the radiosurgery. Fig
6-72 Polyether impression showing minimum thickness and height indicates that retraction was obtained using a single
impregnated cord and radiosurgery.
.. various clinical stages, and the health of the gingiva. patibility between the polyether material and the alu
In the presence of thin periodontium that is already m inum chloride. Horizontal displacement can be
at risk of gingival recession, the authors recommend achieved with a second retraction cord, xpasyl, or
nonimpregnated, compact no. ooo cords (Uitrapak radiosurgey.
Knitted Cord, Ultradent) or 2/o silk sutures for verti Though the literature specifies the quantity of
cal retraction. Horizontal retraction should be ob required horizontal displacement as o.s mm for im
tained using mechanical or mechanicochemical means pressions using elastomeric materials and t m m for
(eg, xpasyl), but in most cases the use of a second impressions using irreversible hydrocolloids,>B these
cord should be avoided. values are too high to be considered noninvasive.
For thick periodontium, where the risk of subse Modern elastomeric materials have such a high de
quent gingival recession is minimized, a twisted no. gree of tear strength resistance that they can record
oo cord impregnated with aluminum sulfate (Gingi the finish line and the intact tooth structure beyond
Aid Z-Twist), or a nonimpregnated compact no. ooo the fi nish line using a thickness level below litera
cord (Uitrapak) soaked in aluminum chloride (Hemo ture recommendations. Because hydrocolloid i mpres
dent, Premier) can be used. If polyether impression sion materials require invasive horizontal retraction,
material is used, the area should be rinsed copious the authors do not use them (Fig 6-72). ..
ly before the impression is taken to prevent incom-
M I N I M A L H O R I Z O N TA L D E F L E C T I O N
Fig 6-67 Occlusal view of partially obscured retraction cords around two maxillary right t .. th after repositioning and com
pleting the finish line. The radiosurgery technique removes minimal amounts of gingival tissue with a radioscalpel to leave
the finish line visible and ready for impression material. Fig 6-68 Point of the radioscalpet used to remove excess tissue. A
plastic (noncondu ctive) mirror and a medium-grit disk soaked in alcohol are also used in radiosurgery. Figs 6-69 and 6-70 Cut
progression of the working point. as s"n through the stereomicroscope in indirect vision. Radiosurgery is never used on the
buccal aspect of the tooth. The small tip of a high-frequency radioscalpel is very precise. and the presence of the first
retraction cord helps the clinician to avoid errors of depth or direction. Fig 6-71 View of same tooth after removal of a thin
band of gingival tissue that obscured the retraction cord. The sulcus shows no signs of bl .. ding after the radiosurgery. Fig
6-72 Polyether impression showing minimum thickness and height indicates that retraction was obtained using a single
impregnated cord and radiosurgery.
.. various clinical stages, and the health of the gingiva. patibility between the polyether material and the alu
In the presence of thin periodontium that is already m inum chloride. Horizontal displacement can be
at risk of gingival recession, the authors recommend achieved with a second retraction cord, xpasyl, or
nonimpregnated, compact no. ooo cords (Uitrapak radiosurgey.
Knitted Cord, Ultradent) or 2/o silk sutures for verti Though the literature specifies the quantity of
cal retraction. Horizontal retraction should be ob required horizontal displacement as o.s mm for im
tained using mechanical or mechanicochemical means pressions using elastomeric materials and t m m for
(eg, xpasyl), but in most cases the use of a second impressions using irreversible hydrocolloids,>B these
cord should be avoided. values are too high to be considered noninvasive.
For thick periodontium, where the risk of subse Modern elastomeric materials have such a high de
quent gingival recession is minimized, a twisted no. gree of tear strength resistance that they can record
oo cord impregnated with aluminum sulfate (Gingi the finish line and the intact tooth structure beyond
Aid Z-Twist), or a nonimpregnated compact no. ooo the fi nish line using a thickness level below litera
cord (Uitrapak) soaked in aluminum chloride (Hemo ture recommendations. Because hydrocolloid i mpres
dent, Premier) can be used. If polyether impression sion materials require invasive horizontal retraction,
material is used, the area should be rinsed copious the authors do not use them (Fig 6-72). ..
ly before the impression is taken to prevent incom-
. T h e authors' philosophy regarding restorative nique, preferring instead methods of retraction that
work is to favor techniques that cause the least trau accomplish the minimum amount of horizontal dis
ma to tooth structure and gingiva; the authors rec placement-about 0.2 m m between the retraction
ommend the s i ng le-co rd technique, the selective cord and the restoration margin3•-required for
Figs 6-73 and 6-74 Clinical case of a 30-year-old woman who requested the restoration of the metal-ceramic crown on the maxillary left cen
tral incisor. After the crown has been removed. an inadequate preparation is revealed. with a post and core of dubious function. Fig 6-75 double-cord technique, the use of a single cord com modern elastomeric i mpression materials.3S Such
Diagnostic waxup The planned restoration of the left central incisor and the porcelain laminate veneer for the right central in cisor wilt give
the central incisors new length and luminosity Fig 6-76 Removal of the dowel and bleaching of the nonvital tooth provided a suitable tooth bined with xpasyl, or even radiosurgery to remove techniques enable the clinician to accomplish pre
preparation for a feldspathic ceramic crown. Fi g 6-77 After whitening. the tooth was reconstructed with a fiberglass dowel, and a no. DO small amounts of tissue (figs 6·73 to 6·88). The cise repositioning of the restoration margin without
retraction cord was placed. Fig 6-78 Apical retraction as viewed through the stereomicroscope. Fig 6-79 Finish line is repositioned with ultra
sonic tools and finished with a rounded chisei iDeppeler D M l l . authors discourage the use of the double-cord tech- risking the stability of the gingival tissue. •
00 111
. T h e authors' philosophy regarding restorative nique, preferring instead methods of retraction that
work is to favor techniques that cause the least trau accomplish the minimum amount of horizontal dis
ma to tooth structure and gingiva; the authors rec placement-about 0.2 m m between the retraction
ommend the s i ng le-co rd technique, the selective cord and the restoration margin3•-required for
Figs 6-73 and 6-74 Clinical case of a 30-year-old woman who requested the restoration of the metal-ceramic crown on the maxillary left cen
tral incisor. After the crown has been removed. an inadequate preparation is revealed. with a post and core of dubious function. Fig 6-75 double-cord technique, the use of a single cord com modern elastomeric i mpression materials.3S Such
Diagnostic waxup The planned restoration of the left central incisor and the porcelain laminate veneer for the right central in cisor wilt give
the central incisors new length and luminosity Fig 6-76 Removal of the dowel and bleaching of the nonvital tooth provided a suitable tooth bined with xpasyl, or even radiosurgery to remove techniques enable the clinician to accomplish pre
preparation for a feldspathic ceramic crown. Fi g 6-77 After whitening. the tooth was reconstructed with a fiberglass dowel, and a no. DO small amounts of tissue (figs 6·73 to 6·88). The cise repositioning of the restoration margin without
retraction cord was placed. Fig 6-78 Apical retraction as viewed through the stereomicroscope. Fig 6-79 Finish line is repositioned with ultra
sonic tools and finished with a rounded chisei iDeppeler D M l l . authors discourage the use of the double-cord tech- risking the stability of the gingival tissue. •
00 111
Fig 6-80 Use of kaolin and aluminum chloride IExpasyt) allows for greater control of the interproximal tissue and increased horizontal retraction. Fig 6-81 Detail of the impression. Note the distinct and detailed finish line with the proper linearity.
Fig 6-81 Effect of Expasyt at the moment of impression taking. Fig 6-83 Feldspathic ceramic crown and porcelain laminate veneer on the master cast.
Fig 6-84 Patient's smile 15 days alter cementation.
Fig 6-80 Use of kaolin and aluminum chloride IExpasyt) allows for greater control of the interproximal tissue and increased horizontal retraction. Fig 6-81 Detail of the impression. Note the distinct and detailed finish line with the proper linearity.
Fig 6-81 Effect of Expasyt at the moment of impression taking. Fig 6-83 Feldspathic ceramic crown and porcelain laminate veneer on the master cast.
Fig 6-84 Patient's smile 15 days alter cementation.
Fig 6-85 Complete smile. Figs 6-87 and 6-88 lateral appearance of the restoration under the stereomicroscope. further illustrating its harmony with the natural denti
Fig 6-86 Overall appearance of restorations in relation to the form and esthetics of the adjacent natural dentition. tion in terms both of color and shape. The emergence profile of the restorations from the gingival sulcus is particularly effective.
Fig 6-85 Complete smile. Figs 6-87 and 6-88 lateral appearance of the restoration under the stereomicroscope. further illustrating its harmony with the natural denti
Fig 6-86 Overall appearance of restorations in relation to the form and esthetics of the adjacent natural dentition. tion in terms both of color and shape. The emergence profile of the restorations from the gingival sulcus is particularly effective.
CHAPTER 6
9· Kois JC. Altering gingival levels: The restorative connec· 18. A2Zi R, Tsao TF. Carranza FA. Kenney EB. Comparative 27. Bata JP. Fe1gal R), Colman HL. Cytotoxic efects of gin·
REFEREN CES
11on. Part 1: Biologic variables. J Esthet Dent 1994;6:3-9. study of gingival retraction methods. 1 Prosthet Dent gival retraction medicaments on human gingival ibro·
1. Nevins M. Skurow HM. The intracrevicular restorative 10. Tarnow D. Stahl SS. Magner A. Zamzok ). Human gingi· 1983:50:561-565. blasts [abstract 1411t J Dent Res 1987;66(spec issue) :283.
margin, the biologic width, and the maintenance of the val attachment responses to subgingival crown place 19. Tebrock OC. issue retraction for esthetic ceramometal 28. Albers HF. Impressions: A Text for Selection of Materials
gingival margin. lnt J Periodontics Restorative Dent ment. Marginal remodelling. J Clin Periodontal 1986;13: crowns. J Prosthet Dent 1986:55:21-23. and Techniques. Santa Rosa. A: Alto Books, 199>:45-46.
1984:4:3>-49· 563-569. 20. Runyan DA. Reddy TG Jr. Shimada LM. Auid absorbency 29. Phillips RW. Skinne(s Science of Dental aterials. ed 9·
2. Reiman MS. Exposure of subgingival margins by non· 11. Walie GN, van der Weijden FA. Spanauf AJ. de Quincey of retraction cords after soaking in aluminum chloride Philadelphia: Saunders. 1991:45-46.
surgical gingival displacement. J Prosthet Dent 1976:36: GN. Lengthening clinical crowns: A solution for specific solution. J Prosthet Dent 1988;6o:676678. 30. agne P. Belser U. Bonded Porcelain Restorations in the
64�54· periodontal, restorative and esthetic problems. Quintes· 21. Kopac I, Cvetko E, arion L. Gingival inlammatoy re· Anterior Dentition: A Biomimetic Approach. Berlin: Quin·
3. Richter·Snapp K. Aquilino SA. Svare W. Turner A. sence lnt 1994:25:81-88. sponse induced by chemical retraction agents in beagle tessence. 202:244-247.
Change in marginal it as related to margin design. alloy 12. Nemez H, Donovan T, Landesman H. Exposing the gin· dogs. tnt J Prosthodont 2002;15:14-19. 31. Laufer BZ. Saharav H. Langer H. Cardash S. The closure
type, and porcelain proximity in porcelain·fused-to·metal gival margin: A systematic approach for the control of 22. Shaw DH. Krejci RF. Gingival retraction preference of of the gingival crevice following gingival retraction for
restorations. I Prosthet Dent 1988:6o:435-439· hemorrhage. J Prosthet Dent 1984:51:647-651. dentists in general practice. Quintessence lnt 1986;17: impression making. J Oral Rehabil 1997;24:62�35.
4. Ingber )S. Rose LF. Coslet )G. The "biologic width": A 13. Loe H, Silness 1. Tissue reactions to string packs used 277-280. 32. Sherman JA. Electrosurgical accessories: New advance·
concept in periodontics and restorative dentistry. Alpha in ixed restorations. J Prosthet Dent 1963;13:318-323. 23. Jokstad A. Clinical trial of gingival retraction cords. J ments. Oral Health 1986;76:37-39.
Omegan 1977;70:62-65. 4 · Magne P. Magne M. Belser U. Impressions and esthetic Prosthet Dent 1999:81:258-261. 33· Kalkwaf KL. Krejci RF. Shaw DH. Edison AR. Histologic
5· Gargiulo A. Wenz FM. Orban B). Dimensions and rela· rehabilitation: The preparatory work, clinical procedures 24. Benson BW. Bamberg TJ. Hatch RA. Homan W )r. Tissue evaluation of gingival response to an electrosurgical
tion of the dentogingival junction in humans. J Peri and materials (in French and German]. Schweiz Monats· displacement methods in ixed prosthodontics. I Prosthet blade. J Oral axilloac Surg 1987:45:671-674.
odontal 1961:32: 261-267. schr Zahnmed 1995:105:1302-1316. Dent 1986:55:175-181. 34· Lauer BZ, Saharav H . Cardash HS. The linear accuracy
6. Dragoo MR. Williams GB. Periodontal tissue reactions to 15. Laufer BZ. Saharav H, Ganor Y. Cardash HS. The efect 25. Shaw DH, Krejci RF. Cohen OM. Retraction cords with of impressions and stone dies as aected by the thick·
restorative procedures. lnt I eriodontics Restorative of marginal thickness on the distortion of diferent im· aluminum chloride. Efect on the gingiva. Oper Dent ness of the impression margin. lnt J Prosthodont 1994;
Dent 1981:1:8-23. pression materials. J Prosthet Dent 1996:76:466-471. 1980;5:138-144· 7:247-252.
7. Dragoo MR. Williams GB. Periodontal tissue reactions to 16. Rue! ). Schuessler PJ. Malament K. Mori D. Efect of re· 26. de Camargo LM. Chee W, Donovan TE. Inhibition of 35· Saharav H. Kupeshmidt I. Laufer BZ. Cardash HS. The
restorative procedures, part II. lnt I Periodontics Restor· traction procedures on the periodontium in humans. J polymerization of polvinyl siloxanes by medicaments eect of sulcular width on the linear accuracy of impres
alive Dent 1982;2:34-45. Prosthet Dent 1980:44:5o8-515. used on gingival retraction cords. I Prosthet Dent 1993: sion materials in the presence of an undercut. lnt J
8. acek JS. Gher ME, Assad DA, Richardson AC, Giam· 17. de Gennaro GG, Landesman HM. Calhoun )E. Martinol 70:114-117. Prosthodont 2004;17:585-589.
barresi ll. The dimensions of the human dentogingival I. A comparison of gingival inlammation related to
junction. lnt J Periodontics Restorative Dent 1994;14: retraction cords. J Prosthet Dent 1982;47:384-386.
154-165.
207
CHAPTER 6
9· Kois JC. Altering gingival levels: The restorative connec· 18. A2Zi R, Tsao TF. Carranza FA. Kenney EB. Comparative 27. Bata JP. Fe1gal R), Colman HL. Cytotoxic efects of gin·
REFEREN CES
11on. Part 1: Biologic variables. J Esthet Dent 1994;6:3-9. study of gingival retraction methods. 1 Prosthet Dent gival retraction medicaments on human gingival ibro·
1. Nevins M. Skurow HM. The intracrevicular restorative 10. Tarnow D. Stahl SS. Magner A. Zamzok ). Human gingi· 1983:50:561-565. blasts [abstract 1411t J Dent Res 1987;66(spec issue) :283.
margin, the biologic width, and the maintenance of the val attachment responses to subgingival crown place 19. Tebrock OC. issue retraction for esthetic ceramometal 28. Albers HF. Impressions: A Text for Selection of Materials
gingival margin. lnt J Periodontics Restorative Dent ment. Marginal remodelling. J Clin Periodontal 1986;13: crowns. J Prosthet Dent 1986:55:21-23. and Techniques. Santa Rosa. A: Alto Books, 199>:45-46.
1984:4:3>-49· 563-569. 20. Runyan DA. Reddy TG Jr. Shimada LM. Auid absorbency 29. Phillips RW. Skinne(s Science of Dental aterials. ed 9·
2. Reiman MS. Exposure of subgingival margins by non· 11. Walie GN, van der Weijden FA. Spanauf AJ. de Quincey of retraction cords after soaking in aluminum chloride Philadelphia: Saunders. 1991:45-46.
surgical gingival displacement. J Prosthet Dent 1976:36: GN. Lengthening clinical crowns: A solution for specific solution. J Prosthet Dent 1988;6o:676678. 30. agne P. Belser U. Bonded Porcelain Restorations in the
64�54· periodontal, restorative and esthetic problems. Quintes· 21. Kopac I, Cvetko E, arion L. Gingival inlammatoy re· Anterior Dentition: A Biomimetic Approach. Berlin: Quin·
3. Richter·Snapp K. Aquilino SA. Svare W. Turner A. sence lnt 1994:25:81-88. sponse induced by chemical retraction agents in beagle tessence. 202:244-247.
Change in marginal it as related to margin design. alloy 12. Nemez H, Donovan T, Landesman H. Exposing the gin· dogs. tnt J Prosthodont 2002;15:14-19. 31. Laufer BZ. Saharav H. Langer H. Cardash S. The closure
type, and porcelain proximity in porcelain·fused-to·metal gival margin: A systematic approach for the control of 22. Shaw DH. Krejci RF. Gingival retraction preference of of the gingival crevice following gingival retraction for
restorations. I Prosthet Dent 1988:6o:435-439· hemorrhage. J Prosthet Dent 1984:51:647-651. dentists in general practice. Quintessence lnt 1986;17: impression making. J Oral Rehabil 1997;24:62�35.
4. Ingber )S. Rose LF. Coslet )G. The "biologic width": A 13. Loe H, Silness 1. Tissue reactions to string packs used 277-280. 32. Sherman JA. Electrosurgical accessories: New advance·
concept in periodontics and restorative dentistry. Alpha in ixed restorations. J Prosthet Dent 1963;13:318-323. 23. Jokstad A. Clinical trial of gingival retraction cords. J ments. Oral Health 1986;76:37-39.
Omegan 1977;70:62-65. 4 · Magne P. Magne M. Belser U. Impressions and esthetic Prosthet Dent 1999:81:258-261. 33· Kalkwaf KL. Krejci RF. Shaw DH. Edison AR. Histologic
5· Gargiulo A. Wenz FM. Orban B). Dimensions and rela· rehabilitation: The preparatory work, clinical procedures 24. Benson BW. Bamberg TJ. Hatch RA. Homan W )r. Tissue evaluation of gingival response to an electrosurgical
tion of the dentogingival junction in humans. J Peri and materials (in French and German]. Schweiz Monats· displacement methods in ixed prosthodontics. I Prosthet blade. J Oral axilloac Surg 1987:45:671-674.
odontal 1961:32: 261-267. schr Zahnmed 1995:105:1302-1316. Dent 1986:55:175-181. 34· Lauer BZ, Saharav H . Cardash HS. The linear accuracy
6. Dragoo MR. Williams GB. Periodontal tissue reactions to 15. Laufer BZ. Saharav H, Ganor Y. Cardash HS. The efect 25. Shaw DH, Krejci RF. Cohen OM. Retraction cords with of impressions and stone dies as aected by the thick·
restorative procedures. lnt I eriodontics Restorative of marginal thickness on the distortion of diferent im· aluminum chloride. Efect on the gingiva. Oper Dent ness of the impression margin. lnt J Prosthodont 1994;
Dent 1981:1:8-23. pression materials. J Prosthet Dent 1996:76:466-471. 1980;5:138-144· 7:247-252.
7. Dragoo MR. Williams GB. Periodontal tissue reactions to 16. Rue! ). Schuessler PJ. Malament K. Mori D. Efect of re· 26. de Camargo LM. Chee W, Donovan TE. Inhibition of 35· Saharav H. Kupeshmidt I. Laufer BZ. Cardash HS. The
restorative procedures, part II. lnt I Periodontics Restor· traction procedures on the periodontium in humans. J polymerization of polvinyl siloxanes by medicaments eect of sulcular width on the linear accuracy of impres
alive Dent 1982;2:34-45. Prosthet Dent 1980:44:5o8-515. used on gingival retraction cords. I Prosthet Dent 1993: sion materials in the presence of an undercut. lnt J
8. acek JS. Gher ME, Assad DA, Richardson AC, Giam· 17. de Gennaro GG, Landesman HM. Calhoun )E. Martinol 70:114-117. Prosthodont 2004;17:585-589.
barresi ll. The dimensions of the human dentogingival I. A comparison of gingival inlammation related to
junction. lnt J Periodontics Restorative Dent 1994;14: retraction cords. J Prosthet Dent 1982;47:384-386.
154-165.
207
C H A P T E R 7
C L I N I C AL C O N S I D ERAT I O N S
F O R P R O V I S I O NAL
P R O S T H E SES
FIG 7-1 FIG 7-2
P
rovisional prosthodontic procedures are fun • Provide protection for the pulpal organ
damental to realizing a prosthetic restoration, • Ensure a good fit and stable position
whether involving a single tooth or multiple • Allow function in occlusion
teeth. Most clinicians now recognize the importance • Permit easy access for hygiene
of minimizing the damage caused during impression • Safeguard the health of the periodontal margin
taking. We also now understand the need to support • Exhibit good strength and retention
the tissues with provisionals that are anatomically • Guarantee acceptable esthetics
suitable in terms of shape, size, and length and that
have perfectly polished margins in order to promote A broad range of technologies and materials are
satisfactory healing after the impression phase.'-3 In available for fabricating provisionals that meet these
complex cases, in addition to conditioning and di standards. With respect to how long they are expect FIG 7-3 FIG 7-4
recting the gingival tissues, the provisional restora ed to last, provisional prostheses are classified as
tion is essential diagnostically and therapeutically in either short term or long term.
the initial stage of treatment. In simpler cases, it Short-term provisional prostheses are further
promotes correct maturation and integration of the subclassified as irst, second, or third-generation, de
soft tissues while performing its essential function, pending on their purpose:
which is to protect the pulp and preserve the spatial
relationship with adjacent and opposing teeth (Figs 1. First-generation provisional
7-1 to 7-6). a. Preformed direct provisional prosthesis
b. Provisional prosthesis with a thermoplastic or
silicone index
CHARACTERISTICS A N D
FIG 7-5 FIG 7-6
c. Provisional based on a diagnostic waxup before
CLASS I FI CATI O N O F PROVI S I O NAL
preparation of the teeth
RESTORATIONS
2. Second-generation provisional
T h e ideal qualities of a provisional prosthetic res 3- Third-generation provisional ..
Fig 7-1 A 44-year-old man presented for emergency treatment as a result of the decementation of the maxillary right lateral incisor restora
toration, as described by Shillingburg et al,4 are as tion. There was also secondary infiltration of lhe crowns on lhe right canine and left lateral incisor. The restored canine had a n artificial root.
which was needed because the tooth showed marked recession. The crowns were replaced with two immediate provisional restorations. using
follows: direct preformed shells. Fig 7-2 Hole the initial adaptation of the provisional prosthesis on the canine and the residual lateral i n cisor. '•g '-3
Root canal treatment was redone. and lhe teeth were re-prepared for reconstruction with alumina core ceramic crowns. : , Replacement
of the direcl provisional crowns w1th two second-generation provisionals. fabricated after the teeth were prepared and a polyether impres
sion made. Fig• 7-5 and 7-6 Before and after cementation of the permanent crowns. respectively.
8
C H A P T E R 7
C L I N I C AL C O N S I D ERAT I O N S
F O R P R O V I S I O NAL
P R O S T H E SES
FIG 7-1 FIG 7-2
P
rovisional prosthodontic procedures are fun • Provide protection for the pulpal organ
damental to realizing a prosthetic restoration, • Ensure a good fit and stable position
whether involving a single tooth or multiple • Allow function in occlusion
teeth. Most clinicians now recognize the importance • Permit easy access for hygiene
of minimizing the damage caused during impression • Safeguard the health of the periodontal margin
taking. We also now understand the need to support • Exhibit good strength and retention
the tissues with provisionals that are anatomically • Guarantee acceptable esthetics
suitable in terms of shape, size, and length and that
have perfectly polished margins in order to promote A broad range of technologies and materials are
satisfactory healing after the impression phase.'-3 In available for fabricating provisionals that meet these
complex cases, in addition to conditioning and di standards. With respect to how long they are expect FIG 7-3 FIG 7-4
recting the gingival tissues, the provisional restora ed to last, provisional prostheses are classified as
tion is essential diagnostically and therapeutically in either short term or long term.
the initial stage of treatment. In simpler cases, it Short-term provisional prostheses are further
promotes correct maturation and integration of the subclassified as irst, second, or third-generation, de
soft tissues while performing its essential function, pending on their purpose:
which is to protect the pulp and preserve the spatial
relationship with adjacent and opposing teeth (Figs 1. First-generation provisional
7-1 to 7-6). a. Preformed direct provisional prosthesis
b. Provisional prosthesis with a thermoplastic or
silicone index
CHARACTERISTICS A N D
FIG 7-5 FIG 7-6
c. Provisional based on a diagnostic waxup before
CLASS I FI CATI O N O F PROVI S I O NAL
preparation of the teeth
RESTORATIONS
2. Second-generation provisional
T h e ideal qualities of a provisional prosthetic res 3- Third-generation provisional ..
Fig 7-1 A 44-year-old man presented for emergency treatment as a result of the decementation of the maxillary right lateral incisor restora
toration, as described by Shillingburg et al,4 are as tion. There was also secondary infiltration of lhe crowns on lhe right canine and left lateral incisor. The restored canine had a n artificial root.
which was needed because the tooth showed marked recession. The crowns were replaced with two immediate provisional restorations. using
follows: direct preformed shells. Fig 7-2 Hole the initial adaptation of the provisional prosthesis on the canine and the residual lateral i n cisor. '•g '-3
Root canal treatment was redone. and lhe teeth were re-prepared for reconstruction with alumina core ceramic crowns. : , Replacement
of the direcl provisional crowns w1th two second-generation provisionals. fabricated after the teeth were prepared and a polyether impres
sion made. Fig• 7-5 and 7-6 Before and after cementation of the permanent crowns. respectively.
8
CHAPTER 1
Clinical Considerations for Provisional Prostheses
.. Long-term provisional prostheses have a metal more marginal discrepancies than composite based .. PROCEDU RES FOR PROVI S I O NAL tends to be difficult to work with and forms bubbles
frame with a base that can be filled to provide good on bisphenol glycidyl methacrylate (bis-GMA) or RESTORAT I O N S that impede satisfactory adhesion to the thermo
stabilization and resistance in occlusion. polyethyl methacrylate and vinylethyl methacrylate, plastic shell (Figs 7-7 and 7-8).
Various techniques can be used for fabricating a which had similar values.8 The latter materials are The authors are convinced that adhering to the
Short-term provis ionals
provisional restoration, each one developed to meet among the most frequently used for provisional treatment plan, fabricating the provisional prosthe
the demands of speciic clinical situations. restorations. Christensen9 lists polyethyl methacry First generation sis in the laboratory, and scrupulously monitoring
late, bis-GMA, and the last-generation materials The direct provisional restoration is generally made the operating times will guarantee an optimal func
described in chapter 9 as suitable for this purpose. only in emergencies using a preformed shell (ION, tional and esthetic outcome. Conversely, a lack of
Clinical consi derations and p roced u res
In a study comparing the effect of six resin materi 3M Espe). Made of polycarbonate, these shells are adequate planning will result i n unnecessary loss of
The different techniques for fabricating a provision als,'0 Tjan et al" showed that various materials of classified by type and size/shape rather than func time and energy, while direct preformed and ther
al restoration should be considered in clinical situa similar chemical composition may exhibit wide dif tion or color, which are largely determined by the moplastic shells will need to be replaced after a few
tions that require a provisional with specific charac ferences in precision at the margin. acrylic resin material used for filling them. The shells days since they cannot sustain masticatory loads for
teristics. Selection of a provisional restoration of the Another important feature for the clinician is the are preformed for different tooth shapes (ie, incisors, even a short period.
second or third generation should be based at least amount of heat generated during hardening of both canines, premolars, and molars) and must be re A more suitable solution, in terms of function and
in part on how long it is planned to remain in the the relining materials and the materials used to make placed with laboratory-fabricated provisionals within esthetics, is to prefill the shell or use shell provi
oral cavity. If it is to be used over a relatively long the provisionals with a direct technique. When a tra 1 week. sionals that are fabricated in the lab after the diag
period, the provisional restoration should have a ditional self-curing acrylic resin is used, intrapulpal In the non-emergency setting, provisional pros nostic stone cast or its duplicate has been modified
more precise margin and the capacity to resist temperatures can rise by 0-42°C to 7.21°C during fill theses are made by molding a shell of thermoplas to simulate the ideal preparation. These shells act as
greater masticatory loads. ing. According to a scientific study of the phenome tic material (Erkopress, Erkodent), which is pressure a support for the acrylic resin, which is baked in the
In addition to the risk of marginal infiltration, non, 12 polyethyl methacrylate generated the most shaped after the disk has been preheated to 50°C to lab and can be made by following the indications
teeth that have been prepared and provisionally heat. When using materials that generate a consid 6o°C on the plaster cast. The existing parameters provided by the diagnostic waxup, depending on the
restored tend to exhibit inflammation of the peri erable degree of heat, it is advisable to apply con are not modified in this stage. complexity and requirements of the treatment plane.
odontal margin. Studies have shown that more tinuous jets of air-water spray while the material is A variation of this technique is to make a silicone Once the waxup is duplicated using the proper sili
plaque accumulates on the surface of provisional hardening to counteract the heat as much as possi index from an impression using extrahard (85 cone and poured in plaster, it can provide support
restorations than on the cervical surfaces of adja ble. When selecting a material for intraoral filling, the shores) silicone (Zetalabor, Zhermack). The acrylic for the fabrication of the provisional restoration, act
cent natural teeth.S Therefore, the operator must be potential increase in temperature is an important resin is applied to the silicone index and pressed ing as a mold for the resin, which is cured and then
precise in closing the marginal borders and defining concern for minimizing damage to the pulp chamber. over the preparations until curing is complete. This finished in the laboratory.
the emergence profiles to prevent potential compli The margins of provisional restorations are fin results in immediate realization of a provisional To assist the clinician in controlling the position
cations such as gingival recession_6.7 ished in resin. Because the resin inevitably deforms restoration. of the provisional prosthesis during filling, the labo
The material used to reproduce the finish line of and fractures under stress,'3·'• provisional prosthe The pressed-shell technique produces a provi ratory technician makes an index in extrahard sili
the provisional prosthetic margin has a significant ses must be used for a limited period or checked sional that has the advantage of being very thin and cone (85 shores) that is applied directly to the fin
effect on its precision. A study comparing diferent and replaced frequently. .. thus adapts well to the shape of the preparations ished provisional, forming occlusal stops on the
materials found that epimine presents considerably and the interproximal spaces. Moreover, once the adjacent natural teeth for added stability. The provi
resin curing is finished, it becomes the surface of sional prosthesis is then inserted into the silicone
the provisional restoration. Although the technique index, which facilitates proper positioning on the
adapts readily to the clinical setting, it poses the preparations in terms of axis and d i rection, thus
problem of using a fairly large amount of acrylic eliminating the danger of excessive lengthening or
resin in the office as a support material. Acrylic resin repositioning (Figs 7-9 to 7-13). ..
210
211
CHAPTER 1
.. Long-term provisional prostheses have a metal more marginal discrepancies than composite based .. PROCEDU RES FOR PROVI S I O NAL tends to be difficult to work with and forms bubbles
frame with a base that can be filled to provide good on bisphenol glycidyl methacrylate (bis-GMA) or RESTORAT I O N S that impede satisfactory adhesion to the thermo
stabilization and resistance in occlusion. polyethyl methacrylate and vinylethyl methacrylate, plastic shell (Figs 7-7 and 7-8).
Various techniques can be used for fabricating a which had similar values.8 The latter materials are The authors are convinced that adhering to the
Short-term provis ionals
provisional restoration, each one developed to meet among the most frequently used for provisional treatment plan, fabricating the provisional prosthe
the demands of speciic clinical situations. restorations. Christensen9 lists polyethyl methacry First generation sis in the laboratory, and scrupulously monitoring
late, bis-GMA, and the last-generation materials The direct provisional restoration is generally made the operating times will guarantee an optimal func
described in chapter 9 as suitable for this purpose. only in emergencies using a preformed shell (ION, tional and esthetic outcome. Conversely, a lack of
Clinical consi derations and p roced u res
In a study comparing the effect of six resin materi 3M Espe). Made of polycarbonate, these shells are adequate planning will result i n unnecessary loss of
The different techniques for fabricating a provision als,'0 Tjan et al" showed that various materials of classified by type and size/shape rather than func time and energy, while direct preformed and ther
al restoration should be considered in clinical situa similar chemical composition may exhibit wide dif tion or color, which are largely determined by the moplastic shells will need to be replaced after a few
tions that require a provisional with specific charac ferences in precision at the margin. acrylic resin material used for filling them. The shells days since they cannot sustain masticatory loads for
teristics. Selection of a provisional restoration of the Another important feature for the clinician is the are preformed for different tooth shapes (ie, incisors, even a short period.
second or third generation should be based at least amount of heat generated during hardening of both canines, premolars, and molars) and must be re A more suitable solution, in terms of function and
in part on how long it is planned to remain in the the relining materials and the materials used to make placed with laboratory-fabricated provisionals within esthetics, is to prefill the shell or use shell provi
oral cavity. If it is to be used over a relatively long the provisionals with a direct technique. When a tra 1 week. sionals that are fabricated in the lab after the diag
period, the provisional restoration should have a ditional self-curing acrylic resin is used, intrapulpal In the non-emergency setting, provisional pros nostic stone cast or its duplicate has been modified
more precise margin and the capacity to resist temperatures can rise by 0-42°C to 7.21°C during fill theses are made by molding a shell of thermoplas to simulate the ideal preparation. These shells act as
greater masticatory loads. ing. According to a scientific study of the phenome tic material (Erkopress, Erkodent), which is pressure a support for the acrylic resin, which is baked in the
In addition to the risk of marginal infiltration, non, 12 polyethyl methacrylate generated the most shaped after the disk has been preheated to 50°C to lab and can be made by following the indications
teeth that have been prepared and provisionally heat. When using materials that generate a consid 6o°C on the plaster cast. The existing parameters provided by the diagnostic waxup, depending on the
restored tend to exhibit inflammation of the peri erable degree of heat, it is advisable to apply con are not modified in this stage. complexity and requirements of the treatment plane.
odontal margin. Studies have shown that more tinuous jets of air-water spray while the material is A variation of this technique is to make a silicone Once the waxup is duplicated using the proper sili
plaque accumulates on the surface of provisional hardening to counteract the heat as much as possi index from an impression using extrahard (85 cone and poured in plaster, it can provide support
restorations than on the cervical surfaces of adja ble. When selecting a material for intraoral filling, the shores) silicone (Zetalabor, Zhermack). The acrylic for the fabrication of the provisional restoration, act
cent natural teeth.S Therefore, the operator must be potential increase in temperature is an important resin is applied to the silicone index and pressed ing as a mold for the resin, which is cured and then
precise in closing the marginal borders and defining concern for minimizing damage to the pulp chamber. over the preparations until curing is complete. This finished in the laboratory.
the emergence profiles to prevent potential compli The margins of provisional restorations are fin results in immediate realization of a provisional To assist the clinician in controlling the position
cations such as gingival recession_6.7 ished in resin. Because the resin inevitably deforms restoration. of the provisional prosthesis during filling, the labo
The material used to reproduce the finish line of and fractures under stress,'3·'• provisional prosthe The pressed-shell technique produces a provi ratory technician makes an index in extrahard sili
the provisional prosthetic margin has a significant ses must be used for a limited period or checked sional that has the advantage of being very thin and cone (85 shores) that is applied directly to the fin
effect on its precision. A study comparing diferent and replaced frequently. .. thus adapts well to the shape of the preparations ished provisional, forming occlusal stops on the
materials found that epimine presents considerably and the interproximal spaces. Moreover, once the adjacent natural teeth for added stability. The provi
resin curing is finished, it becomes the surface of sional prosthesis is then inserted into the silicone
the provisional restoration. Although the technique index, which facilitates proper positioning on the
adapts readily to the clinical setting, it poses the preparations in terms of axis and d i rection, thus
problem of using a fairly large amount of acrylic eliminating the danger of excessive lengthening or
resin in the office as a support material. Acrylic resin repositioning (Figs 7-9 to 7-13). ..
210
211
P R O V I S I O N A L S A N A T O M I C A L L Y C O R R E C T M A I N T A I N P R O P E R R E L A T I O N S A N D
I N S H A P E . V O L U M E . A N D E X T E N S I O N P R O P O R T I O N S A C H I E V E D I N L A B
F1g 7-7 8011ng of the stone cast and molded thermoplastic disk. Fig 7-8 The self-curing resin then is applied directly on the prepared tooth Fig 7-11 The silicone guide also makes it easier to obtain the correct axis during filling. Figs 7-12 and 7-13 Clinical case illustrating excellent
until it flits the shell. The advantage of this system is the immediate adaptation because the thickness of the old restoration leaves ample adaptation of the provisional restoration in the maxillary right and left anterior segments and good maturation of the interproximal tissues.
space for fitting in the material. Fig 7-g The provisional restoration of both first and second generations fabricated in the lab is used with an
ultrahard silicone index 185 shores! that functions as a guide during positioning and relining. Fig 1-10 The provisional is supported by the index
and adapts correctly in terms of position and length because the silicone index has occlusal stops that ensure proper repositioning.
212 213
P R O V I S I O N A L S A N A T O M I C A L L Y C O R R E C T M A I N T A I N P R O P E R R E L A T I O N S A N D
I N S H A P E . V O L U M E . A N D E X T E N S I O N P R O P O R T I O N S A C H I E V E D I N L A B
F1g 7-7 8011ng of the stone cast and molded thermoplastic disk. Fig 7-8 The self-curing resin then is applied directly on the prepared tooth Fig 7-11 The silicone guide also makes it easier to obtain the correct axis during filling. Figs 7-12 and 7-13 Clinical case illustrating excellent
until it flits the shell. The advantage of this system is the immediate adaptation because the thickness of the old restoration leaves ample adaptation of the provisional restoration in the maxillary right and left anterior segments and good maturation of the interproximal tissues.
space for fitting in the material. Fig 7-g The provisional restoration of both first and second generations fabricated in the lab is used with an
ultrahard silicone index 185 shores! that functions as a guide during positioning and relining. Fig 1-10 The provisional is supported by the index
and adapts correctly in terms of position and length because the silicone index has occlusal stops that ensure proper repositioning.
212 213
CHAPTER 7
. Second generation in irreversible hydrocolloid material, so that the Filling can be immediate (the traditional type) or A uniform mixture of acrylic resin is applied inside
Second-generation provisionals are fabricated after laboratory is advised of all of the variations in delayed. Immediate filling is generally performed the prepared resin shell, and care is then taken to
elastomeric impressions are taken. A nonimpregnat shape, color, and so forth desired by the patient and directly on the preparations just after the impression position and adapt it correctly in the mouth. Once
ed retraction cord is placed in the gingival sulcus for clinician. is taken, when it is not easy to achieve a satisfac positioned in the mouth, the provisional must be
vetical and horizontal displacement of the tissues tory level of precision. delicately removed during self-curing via a gentle
and after the finish line of the right depth and design To obtain more accurate margins, it is possible to back-and-forth movement over about 2 mm. This
Long-term p rovisionals
has been finished. Apical repositioning of the finish execute a second, delayed filling known as precision prevents adhesion to the prepared tooth and unde
line has not been carried out at this point. This repo When it becomes necessay for therapeutic reasons illing. This is executed on the master cast, after the sired retention in the undercut areas of the adjacent
sitioning of the inish line may be performed imme to prolong the use of a provisional restoration in the final impression has been taken during a subse teeth. It is also advisable to cool the tooth and the
diately or later, during the session when the defini oral cavity, it is advisable to make the prosthesis quent stage, and again after the provisional (which provisional with water. l -'7-•B
tive impression is taken (in which case another refill using acylic resin with a reinforcing metal frame, has already been filled during the initial stage) has In this initial filling, the goal is to make an incisal
ing of the provisional will be necessary). which increases its resistance to functional and mas been decemented. The provisional prosthesis is stop internal to the provisional and again perform
Generally, a provisional prosthesis made in this ticatory loads. This reinforcing structure is made in roughened internally with a bur and relined with initial adaptation of the resin to the surfaces of the
fashion does not need additional refilling or modifi a single-casting monoblock, creating adequate oc composite resin directly on the master cast, thus prepared teeth. The clinician should not pay undue
cation, except perhaps for some isolated areas; this clusal supports and reinforcing connections. It can avoiding errors caused by excess soft tissue and attention to the precision of the prosthetic margins;
is why it is called a precision provisional prosthesis. also be useful in conditioning the sot tissues after oral fluids. eforts should be directed at ensuring that the resin
However, this is possible only if the impression does surgery. For this reason, the provisional prosthesis There are many diferent filling techniques. Among material moistened with monomer adheres well to
not present major distortions (Figs 7-14 to 7-22). can be made so that it can be filled. •s In fact, when these are two that appear similar but actually involve the inish line using a Heidemann spatula. Once the
using provisionals with a metal frame, it is prefer diferent approaches, results, and fabrication times. resin has cured, the provisional is removed from the
Third generation able that the marginal seal be made in resin, so that The first technique, which has been in common use mouth and placed in a pressure pot to accelerate
Finally, there are the third-generation provisionals, if necessary the clinician can execute further refilling for some time, consists of executing successive fill polymerization.
so called because they typically replace the second and adaptation following postsurgical healing or for ings with unheated acrylic resin and waiting for them Once polymerization is complete, another re-illing
generation provisionals. The third-generation provi other situations (Figs 7-40 and 7-41). to harden completely before making any further is needed to define the margin with precision. This
sional is thus fabricated after the definitive impres modifications to the material. In order to accelerate is done ater the excess resin at the margin and the
sion has been taken and the master cast poured. the hardening process and reduce the formation of thin layer that has hardened on the internal axial
This type of provisional prosthesis is used in C L I N I CAL CO N S I D ERATI O N S FOR air bubbles (and thus obtain an ideal compact con surfaces and marginal area has been removed using
complex cases; it ofers the patient and the prostho THE WORKI NG STAGES sistency), the unpolymerized provisional can be tungsten carbide burs. Care should be taken not to
dontic team an opportunity to analyze and confirm immersed in lukewarm water (3o•C)•6 or in a pres remove the resin at the level of the occlusal and
each of the functional and esthetic parameters that sure pot at 4 bars for 10 minutes. palatal internal stops (Fig 7-45).
Filling
were previously proposed and then applied in the Filling involves brushing a layer of petroleum jelly For the second illing, a more liquid form of resin
diagnostic waxup. The final restorative materials will For most types of provisional prostheses made of directly on the preparations to isolate them and pre is placed in the provisional shell. It is important to
be used to reproduce the desired effect after the acrylic resin, the filling and finishing of the pros vent adhesion of the two surfaces as well as over spread and adapt the resin to the margin as accu
patient approves the design (Figs 7-23 to 7-39). thetic margin are critical steps because these proce heating (Figs 7-42 to 7-44). The authors prefer to use rately as possible, using a thin Heidemann spatula
Clin ically, it is possible to use the seco nd dures make it possible to obtain precise restorations a layer of liquid soap to isolate the prepared tooth; coated with monomer (Figs 7-46 and 7-47). The same
generation provisional as a guide for modifications that simulate the emergence profile and support the since soap reduces surface tension more than does procedures used to obtain polymerization in the first
made directly in white wax. After the patient's ap soft tissues (in the same manner as the definitive petroleum jelly, this improves the density of the resin, stage are carried out.
proval, an impression of these modiications is made ceramic restoration). . reducing the risk of creating adaptation defects or air The authors prefer the second technique for intra
bubbles. oral filling because it is simple and fast. It consists .
214
215
CHAPTER 7
. Second generation in irreversible hydrocolloid material, so that the Filling can be immediate (the traditional type) or A uniform mixture of acrylic resin is applied inside
Second-generation provisionals are fabricated after laboratory is advised of all of the variations in delayed. Immediate filling is generally performed the prepared resin shell, and care is then taken to
elastomeric impressions are taken. A nonimpregnat shape, color, and so forth desired by the patient and directly on the preparations just after the impression position and adapt it correctly in the mouth. Once
ed retraction cord is placed in the gingival sulcus for clinician. is taken, when it is not easy to achieve a satisfac positioned in the mouth, the provisional must be
vetical and horizontal displacement of the tissues tory level of precision. delicately removed during self-curing via a gentle
and after the finish line of the right depth and design To obtain more accurate margins, it is possible to back-and-forth movement over about 2 mm. This
Long-term p rovisionals
has been finished. Apical repositioning of the finish execute a second, delayed filling known as precision prevents adhesion to the prepared tooth and unde
line has not been carried out at this point. This repo When it becomes necessay for therapeutic reasons illing. This is executed on the master cast, after the sired retention in the undercut areas of the adjacent
sitioning of the inish line may be performed imme to prolong the use of a provisional restoration in the final impression has been taken during a subse teeth. It is also advisable to cool the tooth and the
diately or later, during the session when the defini oral cavity, it is advisable to make the prosthesis quent stage, and again after the provisional (which provisional with water. l -'7-•B
tive impression is taken (in which case another refill using acylic resin with a reinforcing metal frame, has already been filled during the initial stage) has In this initial filling, the goal is to make an incisal
ing of the provisional will be necessary). which increases its resistance to functional and mas been decemented. The provisional prosthesis is stop internal to the provisional and again perform
Generally, a provisional prosthesis made in this ticatory loads. This reinforcing structure is made in roughened internally with a bur and relined with initial adaptation of the resin to the surfaces of the
fashion does not need additional refilling or modifi a single-casting monoblock, creating adequate oc composite resin directly on the master cast, thus prepared teeth. The clinician should not pay undue
cation, except perhaps for some isolated areas; this clusal supports and reinforcing connections. It can avoiding errors caused by excess soft tissue and attention to the precision of the prosthetic margins;
is why it is called a precision provisional prosthesis. also be useful in conditioning the sot tissues after oral fluids. eforts should be directed at ensuring that the resin
However, this is possible only if the impression does surgery. For this reason, the provisional prosthesis There are many diferent filling techniques. Among material moistened with monomer adheres well to
not present major distortions (Figs 7-14 to 7-22). can be made so that it can be filled. •s In fact, when these are two that appear similar but actually involve the inish line using a Heidemann spatula. Once the
using provisionals with a metal frame, it is prefer diferent approaches, results, and fabrication times. resin has cured, the provisional is removed from the
Third generation able that the marginal seal be made in resin, so that The first technique, which has been in common use mouth and placed in a pressure pot to accelerate
Finally, there are the third-generation provisionals, if necessary the clinician can execute further refilling for some time, consists of executing successive fill polymerization.
so called because they typically replace the second and adaptation following postsurgical healing or for ings with unheated acrylic resin and waiting for them Once polymerization is complete, another re-illing
generation provisionals. The third-generation provi other situations (Figs 7-40 and 7-41). to harden completely before making any further is needed to define the margin with precision. This
sional is thus fabricated after the definitive impres modifications to the material. In order to accelerate is done ater the excess resin at the margin and the
sion has been taken and the master cast poured. the hardening process and reduce the formation of thin layer that has hardened on the internal axial
This type of provisional prosthesis is used in C L I N I CAL CO N S I D ERATI O N S FOR air bubbles (and thus obtain an ideal compact con surfaces and marginal area has been removed using
complex cases; it ofers the patient and the prostho THE WORKI NG STAGES sistency), the unpolymerized provisional can be tungsten carbide burs. Care should be taken not to
dontic team an opportunity to analyze and confirm immersed in lukewarm water (3o•C)•6 or in a pres remove the resin at the level of the occlusal and
each of the functional and esthetic parameters that sure pot at 4 bars for 10 minutes. palatal internal stops (Fig 7-45).
Filling
were previously proposed and then applied in the Filling involves brushing a layer of petroleum jelly For the second illing, a more liquid form of resin
diagnostic waxup. The final restorative materials will For most types of provisional prostheses made of directly on the preparations to isolate them and pre is placed in the provisional shell. It is important to
be used to reproduce the desired effect after the acrylic resin, the filling and finishing of the pros vent adhesion of the two surfaces as well as over spread and adapt the resin to the margin as accu
patient approves the design (Figs 7-23 to 7-39). thetic margin are critical steps because these proce heating (Figs 7-42 to 7-44). The authors prefer to use rately as possible, using a thin Heidemann spatula
Clin ically, it is possible to use the seco nd dures make it possible to obtain precise restorations a layer of liquid soap to isolate the prepared tooth; coated with monomer (Figs 7-46 and 7-47). The same
generation provisional as a guide for modifications that simulate the emergence profile and support the since soap reduces surface tension more than does procedures used to obtain polymerization in the first
made directly in white wax. After the patient's ap soft tissues (in the same manner as the definitive petroleum jelly, this improves the density of the resin, stage are carried out.
proval, an impression of these modiications is made ceramic restoration). . reducing the risk of creating adaptation defects or air The authors prefer the second technique for intra
bubbles. oral filling because it is simple and fast. It consists .
214
215
CHAPT£H 7
7-20
Figs 7-14 and 7-15 Clinical case of a maxillary rehabilitation showing serious gingival recession and secondary caries and decementatio n of the Figs 7-1 g and 7-20 Restoration in feldspathic ceramic. cemented with a n adhesive technique. Note the esthetics a n d functional relationships.
maxillary left central incisor. Figs 7-21 and 7-22 Proper management of the provisional permitted control over esthetic and functional aspects. resulting in a natural smile.
Figs 7-16and7-17 After the inotial provisoonal shell !first generation! was made and the prepared teeth were reconstructed. and after a poly
ether Impression was made with a nonimpregnated retraction cord in place. the stone cast with sectioned dies was used to make the new.
second-generation provisional.
Fog 7-18 The cemen ted provisoonal after clonical ontegration. compared woth the final restoratoon !Fig 7-191. The shape and esthetic parame
_ accordance wolh the ondocaloons furnoshed
ters were altered on by the provisional and the diagnosloc waxup.
217
CHAPT£H 7
7-20
Figs 7-14 and 7-15 Clinical case of a maxillary rehabilitation showing serious gingival recession and secondary caries and decementatio n of the Figs 7-1 g and 7-20 Restoration in feldspathic ceramic. cemented with a n adhesive technique. Note the esthetics a n d functional relationships.
maxillary left central incisor. Figs 7-21 and 7-22 Proper management of the provisional permitted control over esthetic and functional aspects. resulting in a natural smile.
Figs 7-16and7-17 After the inotial provisoonal shell !first generation! was made and the prepared teeth were reconstructed. and after a poly
ether Impression was made with a nonimpregnated retraction cord in place. the stone cast with sectioned dies was used to make the new.
second-generation provisional.
Fog 7-18 The cemen ted provisoonal after clonical ontegration. compared woth the final restoratoon !Fig 7-191. The shape and esthetic parame
_ accordance wolh the ondocaloons furnoshed
ters were altered on by the provisional and the diagnosloc waxup.
217
Fog 7 23 In complex cases. for example. in thos 40-year-old female patoent who presented following contusion of the maxillary central incisors Fig 7-27 The clinical orthodontic examination proposed serial extraction of the first premolars to reduce the overcrowding. followed by ortho
and right lateral oncosor. it may be advisable to follow the fabricatoon step by step usong a doagnostic waxup. dontic treatment and prosthetic rehabilitation to treat the new spaces. or prosthetic treatment alone. The feasibility of both treatment plans.
Fog 7 4 The clonical case presents considerable crowdong. and the treatment plan included possoble orthodontic ontervention. periodontal however. was based on the prosthetic restoration. so the initial clinical diagnosis and the choice of treatment was delayed untol the two pros
surgery woth omplants. and prosthetoc restoratoon The lack of space made it necessary to design a specofoc clinocal example that could be thetic options could be evaluated in the waxups. The difference on the space avaolable in the two options. because of the extractions. provid
shown to the patoent to obtain informed consent for the planned treatment. ed the opportunity to create different forms.
fogs 7·25 a J 7-26 Two dofferent wax models were proposed, the first made wothout considering orthodontic treatment and the second reflect Fogs 7-28 and 7-2g The lack of periodontal support and the short radicular length steered the choice of treatment toward a more conservative
ong a comprehensove treatment plan. onvolvong seroal tooth extractoons and redostrobution of space. Because the central incisors and the right procedure. without additional extractions. The option was for a slower. progressive orthodontic extrusion of the compromised teeth. to pro
lateral were orreparably lost and there was very loltte peroodontal support. on addition to overcrowdong. the selectoon of the type of rehaboli vide more bone and periodontal support for the area afler the extractions. During the stages of slow extrusion. the length of the teeth must
tatoon to propose and then clonocally realoze depended on the optoons chosen in the prelimonary orthodontoc and periodontal plans. be reduced.
Fog 7-30 The compromised teeth were extracted. and the two canines and the lateral incisor were prepared for a prosthesis. After the com
bined orthodontic and periodontal treatment. the provisional stage was managed using three subsequent provisionals to condition the tissues
during the various stages of treatment. using different modalities and procedures. The first provisional was made in the lab. relying on the
forms and dimensions represented in the diagnostic waxup. The goal was to restore the esthetics and function of the extracted teeth and con
dition the tissues in the areas of extraction.
Fig 7-31 After allowing an adequate period for healing (about 3 months). during which the condition of the tissues in the extraction areas was
controlled and modified several times. a precision polyether impression was taken after positioning a nonimpregnated retraction cord
(Ullrapak 000. Ullradent) and completing the finish lines of the preparations to define a reg ular. smooth line. A diamond -grit ball bur was
used to redefine the edentulous areas anatomically and esthetically. (A scalpel may also be used.) The new provisional was made using the
successive layering of dentin and enamel. creating a resin shell simolar to dentin. cast on a silicone ondex. and fonished woth a bur to give it
a natural shape with mamelons. The provisional. properly finished and polished. has been fitted and adapted in the oral cavity. and the
esthetic. functional. and phonetic characteristics have been checked.
211
219
Fog 7 23 In complex cases. for example. in thos 40-year-old female patoent who presented following contusion of the maxillary central incisors Fig 7-27 The clinical orthodontic examination proposed serial extraction of the first premolars to reduce the overcrowding. followed by ortho
and right lateral oncosor. it may be advisable to follow the fabricatoon step by step usong a doagnostic waxup. dontic treatment and prosthetic rehabilitation to treat the new spaces. or prosthetic treatment alone. The feasibility of both treatment plans.
Fog 7 4 The clonical case presents considerable crowdong. and the treatment plan included possoble orthodontic ontervention. periodontal however. was based on the prosthetic restoration. so the initial clinical diagnosis and the choice of treatment was delayed untol the two pros
surgery woth omplants. and prosthetoc restoratoon The lack of space made it necessary to design a specofoc clinocal example that could be thetic options could be evaluated in the waxups. The difference on the space avaolable in the two options. because of the extractions. provid
shown to the patoent to obtain informed consent for the planned treatment. ed the opportunity to create different forms.
fogs 7·25 a J 7-26 Two dofferent wax models were proposed, the first made wothout considering orthodontic treatment and the second reflect Fogs 7-28 and 7-2g The lack of periodontal support and the short radicular length steered the choice of treatment toward a more conservative
ong a comprehensove treatment plan. onvolvong seroal tooth extractoons and redostrobution of space. Because the central incisors and the right procedure. without additional extractions. The option was for a slower. progressive orthodontic extrusion of the compromised teeth. to pro
lateral were orreparably lost and there was very loltte peroodontal support. on addition to overcrowdong. the selectoon of the type of rehaboli vide more bone and periodontal support for the area afler the extractions. During the stages of slow extrusion. the length of the teeth must
tatoon to propose and then clonocally realoze depended on the optoons chosen in the prelimonary orthodontoc and periodontal plans. be reduced.
Fog 7-30 The compromised teeth were extracted. and the two canines and the lateral incisor were prepared for a prosthesis. After the com
bined orthodontic and periodontal treatment. the provisional stage was managed using three subsequent provisionals to condition the tissues
during the various stages of treatment. using different modalities and procedures. The first provisional was made in the lab. relying on the
forms and dimensions represented in the diagnostic waxup. The goal was to restore the esthetics and function of the extracted teeth and con
dition the tissues in the areas of extraction.
Fig 7-31 After allowing an adequate period for healing (about 3 months). during which the condition of the tissues in the extraction areas was
controlled and modified several times. a precision polyether impression was taken after positioning a nonimpregnated retraction cord
(Ullrapak 000. Ullradent) and completing the finish lines of the preparations to define a reg ular. smooth line. A diamond -grit ball bur was
used to redefine the edentulous areas anatomically and esthetically. (A scalpel may also be used.) The new provisional was made using the
successive layering of dentin and enamel. creating a resin shell simolar to dentin. cast on a silicone ondex. and fonished woth a bur to give it
a natural shape with mamelons. The provisional. properly finished and polished. has been fitted and adapted in the oral cavity. and the
esthetic. functional. and phonetic characteristics have been checked.
211
219
Figs 7-36 o 7-3g Views before !Figs 7-36 and 7-38) and after !Figs 7-37 and 7-3 g ) treatment. The esthetic outcome of this complex treatment
Figs 7-32 and 7-33 This second-generation provisional. although quite close to the final shape. shows some imperfections that can be easily
corrected using white wax directly in the patient's mouth and sending the modifications to the lab after having taken an impression in irre is very goad.
versible hydrocolloid.
F1g 7-34 Only at this stage should the clinician proceed to finish the tooth preparations. positioning the finish lines at the desired level. and
take the impression with elastomerit material.
Fig 7-35 It is important to fabri cate a third-generation provisional that wilt exactly replicate the appearance of the final restoration. This last
provisional. once fitted � nd cemented. allows. the patient to check .the esthetic result directly and allows the clinical team to verify all the
parameters and the stability of the marg�nal tiSsues. Further mod1f1tallons can be made if necessary. The final restoration in this case was
done using a porcelain-fused-to- metal crown. involving a metal support structure made in a single casting. No metal is visible at the mar
gin because of the use of the collarless technique. wh1th requires a ceramic shoulder margin.
21
11
Figs 7-36 o 7-3g Views before !Figs 7-36 and 7-38) and after !Figs 7-37 and 7-3 g ) treatment. The esthetic outcome of this complex treatment
Figs 7-32 and 7-33 This second-generation provisional. although quite close to the final shape. shows some imperfections that can be easily
corrected using white wax directly in the patient's mouth and sending the modifications to the lab after having taken an impression in irre is very goad.
versible hydrocolloid.
F1g 7-34 Only at this stage should the clinician proceed to finish the tooth preparations. positioning the finish lines at the desired level. and
take the impression with elastomerit material.
Fig 7-35 It is important to fabri cate a third-generation provisional that wilt exactly replicate the appearance of the final restoration. This last
provisional. once fitted � nd cemented. allows. the patient to check .the esthetic result directly and allows the clinical team to verify all the
parameters and the stability of the marg�nal tiSsues. Further mod1f1tallons can be made if necessary. The final restoration in this case was
done using a porcelain-fused-to- metal crown. involving a metal support structure made in a single casting. No metal is visible at the mar
gin because of the use of the collarless technique. wh1th requires a ceramic shoulder margin.
21
11
CHAPTER 7
• of removing the provisional prosthesis during the Using impressions taken in the office (ie, the clas·
first stage, while the resin is still malleable, and care· sic prefilled·type provisional shells) and those fabri·
fully eliminating excess material using abrasive disks cated from precision impressions with elastomeric
(eg, from Moore) and part of the interior material material and usually the aid of a nonimpregnated
using tungsten carbide burs, so that more nuid mate· denection cord, the authors use the dentin-enamel
rial can be added and the margins can be defined molding technique. This sandwich technique, which
with precision. By not waiting for the resin to hard· can be performed both in the office and in the lab,
en completely, the second filling is made easier. involves two successive pressings. The first uses a
Moreover, the possibility of causing occlusal lifting, dentin resin, which, after roughing up and reducing
which often results from the alternative technique, is the shape of the shell, effectively simulates the
eliminated. properties of natural dentin, with mamelons and
When faced with small defects of marginal or sur· ridges. The second pressing is done directly over the
face adaptation that require slight repairs, it is dentin shell, using a very nuid resin mixture com·
advisable to use a dual-curing resin (Unifast, GC}, posed of 70% enamel and 30% transparent resin to
which is ideal for small amounts of material that are achieve the effect of the incisal characteristics.
then polymerized under blue light. This material has Two types of acrylic resin are used in this direct
good dimensional stability under stress.'9 technique. For provisionals made in the laboratory,
The self-curing resin the authors use most often New Outline resin (Anax Dent) is preferred because
for filling provisionals is Sintodent (Welltrade}, which of its great versatility and superior esthetic quality,
has many important characteristics, as well as especially for incisal and translucent effects. Difer·
antibacterial properties20•2 1 provided by the presence ent color inserts and photopolymerizable transpar·
of benzalkonium chloride, increased hardness, resis· ent inserts are often interposed between the two
tance to wear, and suitability for polishing. 22 A special layers (Creative, Kerr Hawe).
eyedropper included with the product is used to mix Another type of precision provisional involves
the monomer, which is calibrated and produced making the final prosthesis directly on the definitive
specifically to avoid contamination from the external impression. To assist the healing and maturation of
environment. The powder and liquid are blended in the soft tissues after taking the impression, it is
rubber containers, with the liquid added to the pow· important to achieve precision and good seating of
der rather than vice versa, in quantities 20% less than the provisional. However, in this stage it is difficult
those used in normal procedures. Mixing time is gen· to obtain the marginal seal in resin on the prepara·
7-44 7-45
erally about t minute (the material must be mixed tion immediately after the impression is made. This
slowly}; the resin mixture is then allowed to sit for obstacle can be avoided by using third-generation
about 1.5 minutes until the material achieves ideal provisionals made from the definitive impression.
F , 7-40 and 7-41 Construction of a long-term provisional restoration using a g o l d reinforcing structure that includes s o m e occlusal support
consistency and an opaque, fibrous appearance. Second-generation provisionals are made on a points to stabilize occlusion and prevent breakage under masticatory loads.
This resin is also used in procedures involving the stone cast developed from an elastomeric Impression f1g 7-42 first-generation provisional or shell with a silicone index for positioning in the oral cavity. shown on the stone cast.
pressing of the thermoplastic and silicone Indices, in created after vertically retracting the soft tissues with fig 7-43 After the tooth is prepared. it is Immediately isolated with a film of liquid soap before f illi n g .
which a considerable amount of resin is used. For this a nonimpregnated denection cord (Uitrapak ooo}, using �,g 7·4 Provisional filling. The acrylic resin is overflowing after insertion and must still be adapted optimally to the f1nish line
reason, the work is performed in the clinician's office. the sandwich technique. After the fitting, however, it .. Hg 7· 5 First rough1ng of the resin. us1ng a tungsten carbide bur. after the Initial filling. tak1ng care to remove only the inter�or of the walls
and the excess marginal material.
223
CHAPTER 7
• of removing the provisional prosthesis during the Using impressions taken in the office (ie, the clas·
first stage, while the resin is still malleable, and care· sic prefilled·type provisional shells) and those fabri·
fully eliminating excess material using abrasive disks cated from precision impressions with elastomeric
(eg, from Moore) and part of the interior material material and usually the aid of a nonimpregnated
using tungsten carbide burs, so that more nuid mate· denection cord, the authors use the dentin-enamel
rial can be added and the margins can be defined molding technique. This sandwich technique, which
with precision. By not waiting for the resin to hard· can be performed both in the office and in the lab,
en completely, the second filling is made easier. involves two successive pressings. The first uses a
Moreover, the possibility of causing occlusal lifting, dentin resin, which, after roughing up and reducing
which often results from the alternative technique, is the shape of the shell, effectively simulates the
eliminated. properties of natural dentin, with mamelons and
When faced with small defects of marginal or sur· ridges. The second pressing is done directly over the
face adaptation that require slight repairs, it is dentin shell, using a very nuid resin mixture com·
advisable to use a dual-curing resin (Unifast, GC}, posed of 70% enamel and 30% transparent resin to
which is ideal for small amounts of material that are achieve the effect of the incisal characteristics.
then polymerized under blue light. This material has Two types of acrylic resin are used in this direct
good dimensional stability under stress.'9 technique. For provisionals made in the laboratory,
The self-curing resin the authors use most often New Outline resin (Anax Dent) is preferred because
for filling provisionals is Sintodent (Welltrade}, which of its great versatility and superior esthetic quality,
has many important characteristics, as well as especially for incisal and translucent effects. Difer·
antibacterial properties20•2 1 provided by the presence ent color inserts and photopolymerizable transpar·
of benzalkonium chloride, increased hardness, resis· ent inserts are often interposed between the two
tance to wear, and suitability for polishing. 22 A special layers (Creative, Kerr Hawe).
eyedropper included with the product is used to mix Another type of precision provisional involves
the monomer, which is calibrated and produced making the final prosthesis directly on the definitive
specifically to avoid contamination from the external impression. To assist the healing and maturation of
environment. The powder and liquid are blended in the soft tissues after taking the impression, it is
rubber containers, with the liquid added to the pow· important to achieve precision and good seating of
der rather than vice versa, in quantities 20% less than the provisional. However, in this stage it is difficult
those used in normal procedures. Mixing time is gen· to obtain the marginal seal in resin on the prepara·
7-44 7-45
erally about t minute (the material must be mixed tion immediately after the impression is made. This
slowly}; the resin mixture is then allowed to sit for obstacle can be avoided by using third-generation
about 1.5 minutes until the material achieves ideal provisionals made from the definitive impression.
F , 7-40 and 7-41 Construction of a long-term provisional restoration using a g o l d reinforcing structure that includes s o m e occlusal support
consistency and an opaque, fibrous appearance. Second-generation provisionals are made on a points to stabilize occlusion and prevent breakage under masticatory loads.
This resin is also used in procedures involving the stone cast developed from an elastomeric Impression f1g 7-42 first-generation provisional or shell with a silicone index for positioning in the oral cavity. shown on the stone cast.
pressing of the thermoplastic and silicone Indices, in created after vertically retracting the soft tissues with fig 7-43 After the tooth is prepared. it is Immediately isolated with a film of liquid soap before f illi n g .
which a considerable amount of resin is used. For this a nonimpregnated denection cord (Uitrapak ooo}, using �,g 7·4 Provisional filling. The acrylic resin is overflowing after insertion and must still be adapted optimally to the f1nish line
reason, the work is performed in the clinician's office. the sandwich technique. After the fitting, however, it .. Hg 7· 5 First rough1ng of the resin. us1ng a tungsten carbide bur. after the Initial filling. tak1ng care to remove only the inter�or of the walls
and the excess marginal material.
223
CHAPTER 7
� may be necessary to fill up one or more prepared The provisional prosthesis serves an im portant
teeth to improve adaptation of the prosthesis and role in the conditioning of the soft tissues. It also
ensure its stability. This is principally due to the resin provides information regarding occlusion and
shrinkage. This provisional, which replaced the first esthetics. The clinician must fully exploit the oppor
provisional or shell provisional in an intermediate tunities provided by the provisional restoration to
stage of treatment, must be filled after the impres achieve the final objective (Figs 7-6o to 7-82).
sion has been taken if the marginal level is to be A provisional prosthesis represents a great
deepened or modified. opportunity for conditioning and supporting the gin
gival tissues. It also permits proper maturation,
whether after surgery or after preparation. Shaping
Finishing
and modiying the tissues without surgery in an
To finish the provisional prosthesis, tungsten car atraumatic manner can be accomplished for small
bide burs are used for progressive roughening of the modifications, such as shaping and positioning the
margins and the elimination of excess material (Figs gingival contour, by using provisional prostheses
7-48 to 7-53), assisted by an abrasive disk or an that have been properly conditioned on the plaster
intercalary cut bur in the interproximal areas. cast by the dental technician (Fig 7-83).
For polishing, silicone rubber points and wheels Therefore, tissue conditioning may involve one or
are used first (Fig 7-54), followed by goat-hair brush more edentulous areas to create a natural prosthe
es dipped in powdered pumice and a wool brush sis with ovate panties.
soaked in polishing paste (Figs 7-55 and 7-56). Achieving this result in an edentulous area is pos
Polishing is always completed by a pass with a sible only through proper conditioning of the gingi
mechanical polisher (Figs 7-57 to 7-59). val tissue, which is prepared using a rotating hand
piece with a round diamond bur or a radioscalpel
with a lozenge-shaped tip (Figs 7-84 to 7-88) .
TISSUE CON DITI O N I N G WITH THE When this procedure is carried out, at least 2 mm
PROVISIONAL PROSTH ESIS of gingival tissue must remain between the most
apical point of the prepared tissue and the bone
Provisional restorations have various time and crest to avoid unwanted compression and decubitis
modality constraints, depending on the functions lesions, which would threaten the health of the tis
and goals of the treatment, that is, whether it is pri sue and could result in chronic bone innammation
marily an esthetic rehabilitation or a postsurgical, and possible osteolysis. ..
functional operation.
Figs 7-46 and 7-47 Second filling with more liquid resin. keeping the provisional inside the index. The besl technique is to not wait for the resin
to harden completely. but to reinsert i t while it is still malleable in order to avoid the occlusal lifting phenomenon. Removal before it is fully
hardened prevents close adhesion to the prepared tooth and the consequent difficult detachment.
Fig 7 ll The finishing stage begins with the removal of the excess material accumulated at the margin. using a straight handpiece and a tab
oratory tungsten carbide bur IH13HF.104.023 and H l J g _ F$0.023. Komell
Fl1• 7-4� id 7 iO The next step is a pass with the longest bur IH261.EF.104.023). which is more practical in the profile area.
F; 7- 1 nc 7· 52 Having removed the extra resin after filling. a wax crayon is used to highlight where the resin border will contact the finish
line in the intrasulcular zone. The prosthetic margin will have to be carefully poliShed and finished.
m
CHAPTER 7
� may be necessary to fill up one or more prepared The provisional prosthesis serves an im portant
teeth to improve adaptation of the prosthesis and role in the conditioning of the soft tissues. It also
ensure its stability. This is principally due to the resin provides information regarding occlusion and
shrinkage. This provisional, which replaced the first esthetics. The clinician must fully exploit the oppor
provisional or shell provisional in an intermediate tunities provided by the provisional restoration to
stage of treatment, must be filled after the impres achieve the final objective (Figs 7-6o to 7-82).
sion has been taken if the marginal level is to be A provisional prosthesis represents a great
deepened or modified. opportunity for conditioning and supporting the gin
gival tissues. It also permits proper maturation,
whether after surgery or after preparation. Shaping
Finishing
and modiying the tissues without surgery in an
To finish the provisional prosthesis, tungsten car atraumatic manner can be accomplished for small
bide burs are used for progressive roughening of the modifications, such as shaping and positioning the
margins and the elimination of excess material (Figs gingival contour, by using provisional prostheses
7-48 to 7-53), assisted by an abrasive disk or an that have been properly conditioned on the plaster
intercalary cut bur in the interproximal areas. cast by the dental technician (Fig 7-83).
For polishing, silicone rubber points and wheels Therefore, tissue conditioning may involve one or
are used first (Fig 7-54), followed by goat-hair brush more edentulous areas to create a natural prosthe
es dipped in powdered pumice and a wool brush sis with ovate panties.
soaked in polishing paste (Figs 7-55 and 7-56). Achieving this result in an edentulous area is pos
Polishing is always completed by a pass with a sible only through proper conditioning of the gingi
mechanical polisher (Figs 7-57 to 7-59). val tissue, which is prepared using a rotating hand
piece with a round diamond bur or a radioscalpel
with a lozenge-shaped tip (Figs 7-84 to 7-88) .
TISSUE CON DITI O N I N G WITH THE When this procedure is carried out, at least 2 mm
PROVISIONAL PROSTH ESIS of gingival tissue must remain between the most
apical point of the prepared tissue and the bone
Provisional restorations have various time and crest to avoid unwanted compression and decubitis
modality constraints, depending on the functions lesions, which would threaten the health of the tis
and goals of the treatment, that is, whether it is pri sue and could result in chronic bone innammation
marily an esthetic rehabilitation or a postsurgical, and possible osteolysis. ..
functional operation.
Figs 7-46 and 7-47 Second filling with more liquid resin. keeping the provisional inside the index. The besl technique is to not wait for the resin
to harden completely. but to reinsert i t while it is still malleable in order to avoid the occlusal lifting phenomenon. Removal before it is fully
hardened prevents close adhesion to the prepared tooth and the consequent difficult detachment.
Fig 7 ll The finishing stage begins with the removal of the excess material accumulated at the margin. using a straight handpiece and a tab
oratory tungsten carbide bur IH13HF.104.023 and H l J g _ F$0.023. Komell
Fl1• 7-4� id 7 iO The next step is a pass with the longest bur IH261.EF.104.023). which is more practical in the profile area.
F; 7- 1 nc 7· 52 Having removed the extra resin after filling. a wax crayon is used to highlight where the resin border will contact the finish
line in the intrasulcular zone. The prosthetic margin will have to be carefully poliShed and finished.
m
CHAPTER 7
.. The presence of the papillae is fundamental to the papillae rather than letting the soft tissues con
the simulation of a natural prosthesis, and this is tract to close the gap.
possible only if the embrasures are modified with The length of the ovate pontic should be about
several applications of acrylic resin in order to sup 2.5 mm so that the correct amount is positioned in
port the soft tissue (Rgs 7-89 to 7-91). The ideal the interproximal area. This length is necessary to
shape of the papillae can be achieved only with the provide sufficient support for the papillae.
proper provisional, which should have an interprox Yet another procedure to improve the appearance
imal point of contact as far apical as possible. It is of the tissue is closing the interproximal black trian
FIG 7-53 FIG 7-54 FIG 7-55
only when the distance between this point and the gles. The papillae can be stimulated using tools like
bone crest is equal to or less than 5 mm that the the scaler (M23, Hu-Friedy) approximately every 15
outcome can be reliably predicted. 'l days, making sure to keep the distance between the
Another method for achieving proper tissue con point of contact and the bone crest within the limits
ditioning is to insert a false root made of acrylic recommended by Tarnow et al'l (Rgs 7-92 to 7-99). •
resin immediately into the extraction site to guide
FIG 7-56 FIG 7-57
M A X I M U M L E V E L O F P R E C I S I O N
F O R P R O V I S I O N A L R E S T O R A T I O N S
fig 7-5J The smaU tungsten carbide bur IH7HF.014. Komel) enables the technician to get closer to the margin because of its
smaller d1mens1ons and greater control. wh1ch are ideal characteristics for finishing this delicate area.
fig 7-4 The polishing stage begins with a self-polishing silicone rubber tip (No. g 557, Komel).
Figs 7-55 and 7-iiA goat-hair brush soaked in powdered pumice paste and the wool brush soaked in polishing liquid.
fig 7-57 The margin shown at low magnification. properly finished and polished.
Figs 7-58 and 7-� In these two high- magnification images. the excellent finishing of the margin of the provisional restoration
ca n be seen. as can the detail created in the shoulder. Also note the compactness and adaptation of the provisional and its
.
fa1thful reproduction of the charactenshcs of the preparation.
FIG 7-58 FIG 7-59

1
CHAPTER 7
.. The presence of the papillae is fundamental to the papillae rather than letting the soft tissues con
the simulation of a natural prosthesis, and this is tract to close the gap.
possible only if the embrasures are modified with The length of the ovate pontic should be about
several applications of acrylic resin in order to sup 2.5 mm so that the correct amount is positioned in
port the soft tissue (Rgs 7-89 to 7-91). The ideal the interproximal area. This length is necessary to
shape of the papillae can be achieved only with the provide sufficient support for the papillae.
proper provisional, which should have an interprox Yet another procedure to improve the appearance
imal point of contact as far apical as possible. It is of the tissue is closing the interproximal black trian
FIG 7-53 FIG 7-54 FIG 7-55
only when the distance between this point and the gles. The papillae can be stimulated using tools like
bone crest is equal to or less than 5 mm that the the scaler (M23, Hu-Friedy) approximately every 15
outcome can be reliably predicted. 'l days, making sure to keep the distance between the
Another method for achieving proper tissue con point of contact and the bone crest within the limits
ditioning is to insert a false root made of acrylic recommended by Tarnow et al'l (Rgs 7-92 to 7-99). •
resin immediately into the extraction site to guide
FIG 7-56 FIG 7-57
M A X I M U M L E V E L O F P R E C I S I O N
F O R P R O V I S I O N A L R E S T O R A T I O N S
fig 7-5J The smaU tungsten carbide bur IH7HF.014. Komel) enables the technician to get closer to the margin because of its
smaller d1mens1ons and greater control. wh1ch are ideal characteristics for finishing this delicate area.
fig 7-4 The polishing stage begins with a self-polishing silicone rubber tip (No. g 557, Komel).
Figs 7-55 and 7-iiA goat-hair brush soaked in powdered pumice paste and the wool brush soaked in polishing liquid.
fig 7-57 The margin shown at low magnification. properly finished and polished.
Figs 7-58 and 7-� In these two high- magnification images. the excellent finishing of the margin of the provisional restoration
ca n be seen. as can the detail created in the shoulder. Also note the compactness and adaptation of the provisional and its
.
fa1thful reproduction of the charactenshcs of the preparation.
FIG 7-58 FIG 7-59

1
i tl,·l I
Fig 7 60 Clinical case of a 34-year-old male patient who was greatly dissatisfied with his provisional. which was made in another F1g 7·64 Removal of the provisional reveals even more clearly the asymmetry in the positioning of the restorative teeth. The inadequacy of the
clinic. and
wanted to recover the function and esthetics lost following the extraction of the maxillary right central incisor for endodontic forms and height of the prepared teeth can be observed.
reasons.
F1g 7-61 and 7·62 The clinical and radiologic examinations of the teeth. already reduced for prosthetic purposes. showed F1gs 7-65 and 7-66 Initial waxup on the plaster cast. used to formulate a realistic surgical-prosthetic treatment plan.
a false path on the
right lateral 1ncisor. the presence of an incongruous restoration on the left central incisor. and a carbon fiber post on the
left lateral incisor. F1gs 7-67 and 7-68 Preproslhelic surgery reshapes I he bone contours and lhe mucogin � ival defect in lhe edentulous area in a single stage. This
The in1t1al approach involved the endodontic aspect. with resolutiOn of the false path of the right lateral inCISor and the
re-treatment of the resull is obtained with a crown-lengthening procedure and a subepithelial connective t1ssue graft drawn from the palate.
left central incisor.
F1g 7-63 The provisional presented obvious esthetic defects and is clearly unatlractive because of the gross F1gs 7-6g and 7·70 Occlusal views of pre- and postoperative conditions.
mismatch in the gingival levels.
F1g 7·71 SuccesSIVe preproslhetiC reconstructiOn wilh compoSite res1n.
1
i tl,·l I
Fig 7 60 Clinical case of a 34-year-old male patient who was greatly dissatisfied with his provisional. which was made in another F1g 7·64 Removal of the provisional reveals even more clearly the asymmetry in the positioning of the restorative teeth. The inadequacy of the
clinic. and
wanted to recover the function and esthetics lost following the extraction of the maxillary right central incisor for endodontic forms and height of the prepared teeth can be observed.
reasons.
F1g 7-61 and 7·62 The clinical and radiologic examinations of the teeth. already reduced for prosthetic purposes. showed F1gs 7-65 and 7-66 Initial waxup on the plaster cast. used to formulate a realistic surgical-prosthetic treatment plan.
a false path on the
right lateral 1ncisor. the presence of an incongruous restoration on the left central incisor. and a carbon fiber post on the
left lateral incisor. F1gs 7-67 and 7-68 Preproslhelic surgery reshapes I he bone contours and lhe mucogin � ival defect in lhe edentulous area in a single stage. This
The in1t1al approach involved the endodontic aspect. with resolutiOn of the false path of the right lateral inCISor and the
re-treatment of the resull is obtained with a crown-lengthening procedure and a subepithelial connective t1ssue graft drawn from the palate.
left central incisor.
F1g 7-63 The provisional presented obvious esthetic defects and is clearly unatlractive because of the gross F1gs 7-6g and 7·70 Occlusal views of pre- and postoperative conditions.
mismatch in the gingival levels.
F1g 7·71 SuccesSIVe preproslhetiC reconstructiOn wilh compoSite res1n.
1
CHAIII' !
Climcal Considerations for Provisional Prostheses
Figs 7-72 and 7-73 Comparison of the initial situation and that after the endodontic. periodontal. and restorative stages. showing the excellent Figs 7-78 and 7-79 O cclusal and palatal views of the provisional . showing resolution of the gingival defect in relation to the right central incisor
clinical result achieved. and excellent integration with the tissue. even in the palatal area.
Fo.g 1·74 Two months later. it was. possible to make a new. second-generatoon provisional based on the modified anatomy. The change in the Figs 7-80 and 7-81 Condition of the case with the initial provisional and 6 months after surgical treatment and maturation of the soft tissues.
gongoval and dental parameters os evodent. on terms of the wodth-length ratios (the ideal ratio for central incisors is 0.75-0.80). guided by a new provisional prosthesis
Fog 7-75 Provisional and maturong toss � es The papillae must continue to adapt in relation to the provisional The excellent esthetics achieved Fog 7-82 Control radiograph after placement of the final prosthesis Ia zirconium !lava. J M Espel fixed dental prosthesis). showing clinical
.
•n the promoonal and good communiCation were fundamental on obta1n1ng the patient's informed consent. especially considering the new healing from endodontic treatment.
tooth lengths
Fogs 7·76 ao d 7-77 Details of the provisional In the lateral mws
20
231
CHAIII' !
Climcal Considerations for Provisional Prostheses
Figs 7-72 and 7-73 Comparison of the initial situation and that after the endodontic. periodontal. and restorative stages. showing the excellent Figs 7-78 and 7-79 O cclusal and palatal views of the provisional . showing resolution of the gingival defect in relation to the right central incisor
clinical result achieved. and excellent integration with the tissue. even in the palatal area.
Fo.g 1·74 Two months later. it was. possible to make a new. second-generatoon provisional based on the modified anatomy. The change in the Figs 7-80 and 7-81 Condition of the case with the initial provisional and 6 months after surgical treatment and maturation of the soft tissues.
gongoval and dental parameters os evodent. on terms of the wodth-length ratios (the ideal ratio for central incisors is 0.75-0.80). guided by a new provisional prosthesis
Fog 7-75 Provisional and maturong toss � es The papillae must continue to adapt in relation to the provisional The excellent esthetics achieved Fog 7-82 Control radiograph after placement of the final prosthesis Ia zirconium !lava. J M Espel fixed dental prosthesis). showing clinical
.
•n the promoonal and good communiCation were fundamental on obta1n1ng the patient's informed consent. especially considering the new healing from endodontic treatment.
tooth lengths
Fogs 7·76 ao d 7-77 Details of the provisional In the lateral mws
20
231
figs 7-89 and 7-90 The same clinical case during different phases of treatment. Embrasures are evident between three teeth that will be sub
f1g 7 83 The prov isional may act as a guid � to modify the profile and the relationship with the gingival tissue. for example. in the shifting of
_ wh1ch._ sequently restored with ceramic restorations. The provisional is made using a direct technique with preformed shells and will later be
the g1ng1val zenlth. when moved d1stally. confers a more natural appearance. To achieve this. the dental technician must remove the
replaced with a second-generation provisional. made by means of a polyether precision impression with horizontal displacement established
portion o'. ging1val ti�sue involved from the plaster cut. This will be replaced by the resin of the provisional restoration. thus effecting a by a nonimpre 9 nated retraction cord. Closure of the embrasures between the provisionals is achieved with a direct technique. by adding
_
compression and a sltght 1schem1a of the t1ssues. wh1ch w1ll mature and adapt to the new situation.
dual-curing acrylic resin IU nifast) lfig 7-901.
flg> 7-4ald 7-85 The edentulous aru occupied. by the prosthetic restoration must be well adapted to the mucosal tissue lie. an ovate pontic).
favorable adaptalton can be obtatned only 1f the area 1s prepared with a bur. or with other techniques and instruments such as the f1g 7-91 Note the full maturation of the papillae following cementation of the feldspathic ceramic crowns.
_
rad1oscalpet. and 1f the prov1s1onal presents an ovate shape at the point where it contacts the gingiva.
F11 s 7·86 a 1d 7-87 The edentulous portion that Will be 1n contact w1th the provisional must be usy to clean and accessible with Superfloss !Oral BJ.
ftg 7· The area. properly conditioned. tan stmulate the presence of a root and mask the absence of the natural tooth.
23
figs 7-89 and 7-90 The same clinical case during different phases of treatment. Embrasures are evident between three teeth that will be sub
f1g 7 83 The prov isional may act as a guid � to modify the profile and the relationship with the gingival tissue. for example. in the shifting of
_ wh1ch._ sequently restored with ceramic restorations. The provisional is made using a direct technique with preformed shells and will later be
the g1ng1val zenlth. when moved d1stally. confers a more natural appearance. To achieve this. the dental technician must remove the
replaced with a second-generation provisional. made by means of a polyether precision impression with horizontal displacement established
portion o'. ging1val ti�sue involved from the plaster cut. This will be replaced by the resin of the provisional restoration. thus effecting a by a nonimpre 9 nated retraction cord. Closure of the embrasures between the provisionals is achieved with a direct technique. by adding
_
compression and a sltght 1schem1a of the t1ssues. wh1ch w1ll mature and adapt to the new situation.
dual-curing acrylic resin IU nifast) lfig 7-901.
flg> 7-4ald 7-85 The edentulous aru occupied. by the prosthetic restoration must be well adapted to the mucosal tissue lie. an ovate pontic).
favorable adaptalton can be obtatned only 1f the area 1s prepared with a bur. or with other techniques and instruments such as the f1g 7-91 Note the full maturation of the papillae following cementation of the feldspathic ceramic crowns.
_
rad1oscalpet. and 1f the prov1s1onal presents an ovate shape at the point where it contacts the gingiva.
F11 s 7·86 a 1d 7-87 The edentulous portion that Will be 1n contact w1th the provisional must be usy to clean and accessible with Superfloss !Oral BJ.
ftg 7· The area. properly conditioned. tan stmulate the presence of a root and mask the absence of the natural tooth.
23
7- 9 8
Fig 7-92 The papillae must be stimulated because thw maturatiOn is not yet complete, this can be done mechanically using a scaler IM231 in Figs 7-98 and 7- g9 Magnification of the final restorations i n the same patient.
the area of the papillae in contact with the provisional prosthesis
igs 7-3 and 7-4 Mechanical stimulation of papillae
Fig 7-95 Clinical aspect immediately following mechanical stimulallon
F1gs 7 96 a•d 7-97 The f1nal restorations '" the same pat�ent. after penodontal-prosthet1c treatment
lJS
7- 9 8
Fig 7-92 The papillae must be stimulated because thw maturatiOn is not yet complete, this can be done mechanically using a scaler IM231 in Figs 7-98 and 7- g9 Magnification of the final restorations i n the same patient.
the area of the papillae in contact with the provisional prosthesis
igs 7-3 and 7-4 Mechanical stimulation of papillae
Fig 7-95 Clinical aspect immediately following mechanical stimulallon
F1gs 7 96 a•d 7-97 The f1nal restorations '" the same pat�ent. after penodontal-prosthet1c treatment
lJS
CHAPTER 7
8. Tjan AH. Tjan AH, Grant BE. Marginal accuracy of ten· 20. Albergo G, Accarisi E, Sampalmieri F, Bedini R, Andreana
REFEREN CES 15. Cho GC, Donovan TE, Chee WWL. Clinical experiences
porary composite crowns. J Prosthet Dent 1987;58: with bonded porcelain laminate veneers. I Cal Dent S. Efect of antimicrobical ingredients on mechanical
t. Harrison JD. Efect of retraction materials on the gingi 417-421. Assoc 1998;26:121-127. performance in acrylic resin !abstract 2128]. J Dent Res
val sulcus epithelium. J Prosthet Dent t96t;11:514. 9· Christensen Gl. Provisional restorations for fixed prosth· t6. Ogawa . Aizawa S, Tanaka M. Matsuya S, Hasegawa A, 1997:76(special issue):279.
2. loe H, Silness 1. Tissue reactions to string packs used odontics. l Am Dent Assoc 1996;127:249-252. Koyano K. Efect of water temperature on the fit of 21. (apelli M, Albergo G, Casolari L, Sampalmieri F, Bedini
in fixed restorations. I Prosthet Dent 1963:t):)t8. to. Moulding MB. Teplitsky PE. lntrapulpal temperature dur· provisional crown margins during polymerization. I R. Antibacterial activity of a resin: A qualitative study. J
3- Dragoo MR, Williams GB. Periodontal tissue reactions to ing direct fabrication of provisional restorations. tnt I Prosthet Dent 1999:82:658661. Dent Res 1998:77:1389.
restorative procedures. Part II. lnt 1 Periodontics Restor Prosthodont 1990:3:299-304. 17. Yuodelis RA, Faucher R. Provisional restorations: An 22. Albergo G, Sampalmieri F, Mattioli Belmonte M, Andre·
ative Dent 1982;2:34-45. tt. Tjan AH, Castelnuovo ). Shiatsu G. Marginal fidelity of integrated approach to periodontics and restorative ana S. Mechanical performance of some dental acrylic
4. Shillingburg HT, Hobo S. Whitsett LD, Jacobi R, Brackett crowns fabricated from six proprietary provisional mate dentisty. Dent Clin North Am t980;24:285-303. resin. J Dent Res t997:76(s):1103.
SE. Fundamentals of Rxed Prosthodontics, ed 3. Chi· rials. l Prosthet Dent 1997;77:482-485. t8. Moulding MB, Loney RW. The efect of cooling tech· 23. Tarnow DP, Magner AW, Fletcher P. The efect of the dis·
cage: Quintessence, 1997- 12. Tjan AH, Grant BE, Godfrey MF Jrd. Temperature rise in niques on intrapulpal temperature during direct abrica· tance from the contact point to the crest of bone on the
5· Luthardt RG, Stossel M, Hinz M, Volland! R. Clinical the pulp chamber during abrication of provisional tion of provisional restorations. lnt I Prosthodont 1991; presence or absence of the interproximal dental papil
performance and periodontal outcome of temporary crowns. J Prosthet Dent 19B9;62:622�26. 4:332-336. la. l Periodontal 1992;63:995996.
crowns and ixed partial dentures: A randomized clinical 13. Blum 1. Weiner S, Berendsen P. Efects of thermocyc\ing 19. Dubois R), Kyriakakis P, Weiner S, Vaidyanathan TK.
trial. J Prosthet Dent 2000;83:32-39. on the margins of transitional acrylic resin crowns. I Efects of occlusal loading and thermocycling on the
6. Donaldson D. Gingival recession associated with tem Prosthet Dent 1991;65:642�46. marginal gaps of light-polymerized and autopolymer·
porary coverage. J Periodontal 1973:44:691�6. 14. Hung CM, Weiner S. Dastane A, Vaidyanathan TK. Efects ized resin provisional crowns. J Prosthet Dent 1999;
7. Donaldson 0. The etioloy of gingival recession associ of thermocycling and occlusal force on the margins of 82:t6t-t66.
ated with temporay crowns. l Periodontol t974:45:46B. provisional acrylic resin crowns. 1 Prosthet Dent
1993:69:573-577·
21
237
CHAPTER 7
8. Tjan AH. Tjan AH, Grant BE. Marginal accuracy of ten· 20. Albergo G, Accarisi E, Sampalmieri F, Bedini R, Andreana
REFEREN CES 15. Cho GC, Donovan TE, Chee WWL. Clinical experiences
porary composite crowns. J Prosthet Dent 1987;58: with bonded porcelain laminate veneers. I Cal Dent S. Efect of antimicrobical ingredients on mechanical
t. Harrison JD. Efect of retraction materials on the gingi 417-421. Assoc 1998;26:121-127. performance in acrylic resin !abstract 2128]. J Dent Res
val sulcus epithelium. J Prosthet Dent t96t;11:514. 9· Christensen Gl. Provisional restorations for fixed prosth· t6. Ogawa . Aizawa S, Tanaka M. Matsuya S, Hasegawa A, 1997:76(special issue):279.
2. loe H, Silness 1. Tissue reactions to string packs used odontics. l Am Dent Assoc 1996;127:249-252. Koyano K. Efect of water temperature on the fit of 21. (apelli M, Albergo G, Casolari L, Sampalmieri F, Bedini
in fixed restorations. I Prosthet Dent 1963:t):)t8. to. Moulding MB. Teplitsky PE. lntrapulpal temperature dur· provisional crown margins during polymerization. I R. Antibacterial activity of a resin: A qualitative study. J
3- Dragoo MR, Williams GB. Periodontal tissue reactions to ing direct fabrication of provisional restorations. tnt I Prosthet Dent 1999:82:658661. Dent Res 1998:77:1389.
restorative procedures. Part II. lnt 1 Periodontics Restor Prosthodont 1990:3:299-304. 17. Yuodelis RA, Faucher R. Provisional restorations: An 22. Albergo G, Sampalmieri F, Mattioli Belmonte M, Andre·
ative Dent 1982;2:34-45. tt. Tjan AH, Castelnuovo ). Shiatsu G. Marginal fidelity of integrated approach to periodontics and restorative ana S. Mechanical performance of some dental acrylic
4. Shillingburg HT, Hobo S. Whitsett LD, Jacobi R, Brackett crowns fabricated from six proprietary provisional mate dentisty. Dent Clin North Am t980;24:285-303. resin. J Dent Res t997:76(s):1103.
SE. Fundamentals of Rxed Prosthodontics, ed 3. Chi· rials. l Prosthet Dent 1997;77:482-485. t8. Moulding MB, Loney RW. The efect of cooling tech· 23. Tarnow DP, Magner AW, Fletcher P. The efect of the dis·
cage: Quintessence, 1997- 12. Tjan AH, Grant BE, Godfrey MF Jrd. Temperature rise in niques on intrapulpal temperature during direct abrica· tance from the contact point to the crest of bone on the
5· Luthardt RG, Stossel M, Hinz M, Volland! R. Clinical the pulp chamber during abrication of provisional tion of provisional restorations. lnt I Prosthodont 1991; presence or absence of the interproximal dental papil
performance and periodontal outcome of temporary crowns. J Prosthet Dent 19B9;62:622�26. 4:332-336. la. l Periodontal 1992;63:995996.
crowns and ixed partial dentures: A randomized clinical 13. Blum 1. Weiner S, Berendsen P. Efects of thermocyc\ing 19. Dubois R), Kyriakakis P, Weiner S, Vaidyanathan TK.
trial. J Prosthet Dent 2000;83:32-39. on the margins of transitional acrylic resin crowns. I Efects of occlusal loading and thermocycling on the
6. Donaldson D. Gingival recession associated with tem Prosthet Dent 1991;65:642�46. marginal gaps of light-polymerized and autopolymer·
porary coverage. J Periodontal 1973:44:691�6. 14. Hung CM, Weiner S. Dastane A, Vaidyanathan TK. Efects ized resin provisional crowns. J Prosthet Dent 1999;
7. Donaldson 0. The etioloy of gingival recession associ of thermocycling and occlusal force on the margins of 82:t6t-t66.
ated with temporay crowns. l Periodontol t974:45:46B. provisional acrylic resin crowns. 1 Prosthet Dent
1993:69:573-577·
21
237
C H A P T E R 8
TE C H N I C AL
C O N S I D ERAT I O N S F O R
P R O V I S I O NAL P R O S T H E S E S
D IAGNOSITIC PROVISIO NAL and with the patient's unique individual features,
such as the smile, face, and personality. Modern Flu 8-1 FIG 8-2
ELEMENTS
treatment abandons the traditional concept of
The provisional prosthesis plays a fundamental part preparing a provisional prosthesis of mediocre or
in various phases of the prosthetic rehabilitation poor quality and later replacing it with an improved
treatment, particularly when many teeth are involved ceramic prosthesis. Treatment must address the ini
and the patient's occlusal scheme requires dramatic tial clinical situation in propotion to its complexity,
change. starting with a diagnostic waxup, which leads to fab
A patient may feel uncomfortable with the func rication of a provisional restoration that incorporates
tion of a provisional prosthesis, with the esthetics, function and esthetics. Both of these requirements
or both. However, provisionalization constitutes a transmit essential diagnostic information for the
TEC H N I CAL D IAG NO STIC A N D ESTH ETI C APPROACH
crucial phase in the overall treatment, and the clini definitive restoration.
cian must try to make the patient as comfortable The diagnostic waxup may be converted initially
with it as possible. All members of the prosthetic into an acrylic resin provisional prosthesis that is
team should approach this early phase of treatment used to analyze and verify the proposed parameters
as an opportunity to establish and strengthen a and determine necessary changes in shape or color
mutually positive relationship with the patient.' before the ceramic restoration is fabricated. This vey
Complex esthetic restorations require a precise crucial phase requires cooperation among all mem
therapeutic approach to ensure that the definitive bers of the prosthetic team to synthesize what they
restoration harmonizes with the surrounding tissues know of the patient's character and communicate this .
Fig 8-1 Provisional diagnostic mock-up constructed directly in the patient's mouth. The teeth are isolated by the clinician
using liquid glycerin or normal liquid soap to ensure the resin can be more readily detached from the prepared teeth.
Fig 8-2 Silicone matrix filled with acrylic rem in the plastic phase. The clinician uses the silicone index implemented on the
diagnostic waxup as a matrix to mold the diagnostic mock-up on the teeth for which the provisional restorations are being
prepared.
Fig 8-3 Immediate appearance of the resin after direct polymerization and subsequent extraction of the silicone matrix. The
acrylic material will be detached later using hand tools.
Fig 8-4 Slack demarcations Indicating corrections to improve the anatomy of the mock-up teeth. FIG 8-3 FIG 8-4
1
C H A P T E R 8
TE C H N I C AL
C O N S I D ERAT I O N S F O R
P R O V I S I O NAL P R O S T H E S E S
D IAGNOSITIC PROVISIO NAL and with the patient's unique individual features,
such as the smile, face, and personality. Modern Flu 8-1 FIG 8-2
ELEMENTS
treatment abandons the traditional concept of
The provisional prosthesis plays a fundamental part preparing a provisional prosthesis of mediocre or
in various phases of the prosthetic rehabilitation poor quality and later replacing it with an improved
treatment, particularly when many teeth are involved ceramic prosthesis. Treatment must address the ini
and the patient's occlusal scheme requires dramatic tial clinical situation in propotion to its complexity,
change. starting with a diagnostic waxup, which leads to fab
A patient may feel uncomfortable with the func rication of a provisional restoration that incorporates
tion of a provisional prosthesis, with the esthetics, function and esthetics. Both of these requirements
or both. However, provisionalization constitutes a transmit essential diagnostic information for the
TEC H N I CAL D IAG NO STIC A N D ESTH ETI C APPROACH
crucial phase in the overall treatment, and the clini definitive restoration.
cian must try to make the patient as comfortable The diagnostic waxup may be converted initially
with it as possible. All members of the prosthetic into an acrylic resin provisional prosthesis that is
team should approach this early phase of treatment used to analyze and verify the proposed parameters
as an opportunity to establish and strengthen a and determine necessary changes in shape or color
mutually positive relationship with the patient.' before the ceramic restoration is fabricated. This vey
Complex esthetic restorations require a precise crucial phase requires cooperation among all mem
therapeutic approach to ensure that the definitive bers of the prosthetic team to synthesize what they
restoration harmonizes with the surrounding tissues know of the patient's character and communicate this .
Fig 8-1 Provisional diagnostic mock-up constructed directly in the patient's mouth. The teeth are isolated by the clinician
using liquid glycerin or normal liquid soap to ensure the resin can be more readily detached from the prepared teeth.
Fig 8-2 Silicone matrix filled with acrylic rem in the plastic phase. The clinician uses the silicone index implemented on the
diagnostic waxup as a matrix to mold the diagnostic mock-up on the teeth for which the provisional restorations are being
prepared.
Fig 8-3 Immediate appearance of the resin after direct polymerization and subsequent extraction of the silicone matrix. The
acrylic material will be detached later using hand tools.
Fig 8-4 Slack demarcations Indicating corrections to improve the anatomy of the mock-up teeth. FIG 8-3 FIG 8-4
1
CHAPTER 8
Technical Considerations for Provisional Prostheses
directly over the teeth involved in the restoration, . The technique consists of adapting the wax uncomfortable with the look and feel of the new
.. information to the dental technician to use in defin
which have been isolated using either petroleum jelly veneers (obtained from the silicone casting molded tooth dimensions when the diagnostic mock-up is
ing the tooth shape of the provisional restoration.
or liquid soap (Figs 8·1 to 8-4). The contours of the on the waxup) on a new cast duplicated from the inserted for the first time. This reaction is both nor
In the authors' practice, a distinction is made be
tween different types of provisional elements: resin mock-up are trimmed of all excess material, and master cast. A silicone index, molded on the new wax mal and understandable since the patient's dental
then it is given to the patient to evaluate at home. veneers, is filled with resin and pressed onto anoth· expression and tooth shape developed gradually over
er cast duplicated from the master cast to obtain the many years. Therefore, it is better to make small pro
• Mock-up
• First-generation shell or prosthesis I n direct or technical mock-up orthodontic mock-up (Figs 8-10 to 8-16). gressive corrections to the length and shape of the
• Second-generation or adapted prosthesis The indirect mock-up technique is undertaken in the teeth in order to minimize the patient's anxiety and
laboratory using two study casts, one made of stone Crown diagnostic mock-up stress, which can lead to a refusal to continue with
and the other of silicone duplication material (Elite A crown-lengthening mock-up renects the planned the treatment.
Mock-up
Double, Zhermack). The diagnostic waxup is applied dimensions of the restored teeth, which can be espe Sometimes the patient's first impression is nega
By t h e term mock-up w e refer to a very t h i n clinical to the first (stone) cast, which is then used by the cially valuable for cases in which a design for reshap tive. When this happens, the clinician must try to
aid that is generally made of acrylic resin and that dental technician to fabricate a mold using extra ing and lengthening the teeth must be completed understand the patient's reaction and then proceed
incorporates each of the new clinical parameters hard (85 shores) silicone (Zetalabor). This silicone before tooth preparation, then the provisional restora to make the necessay adjustments without showing
established by the diagnostic waxup. In practice, this index is later filled with acylic resin and placed tion is immediately executed (Figs 8-17 to 8-20). this to the patient. Above all, the patient should not
negative copy of the diagnostic waxup also serves as directly on the second (silicone) cast, thus producing The acrylic resin mock-up is inserted in the mouth be given the mock-up for in-home analysis until the
an accurate reproduction of it, thus offering the great the mock-up. Inert wax (Schuler Dental) is applied to over the teeth involved in the prosthetic restoration appropriate changes have been made. Through each
advantage of showing the rehabilitation treatment the teeth involved in the restoration to facilitate to allow the clinician to check the occlusion, which phase of treatment, the patient must be informed
integrated in the overall esthetic and functional con removal of the acrylic mock-up. The entire site would have been modified in the previous phase of about all changes that are made, and the clinician
text directly on the patient. The mock-up can serve involved in the provisional restoration with the treatment (Fig 8-21). When occlusal adjustments are must be aware that subjective esthetic evaluation
as an important means of analysis and testing in acrylic resin must be further isolated with a plaster necessay to optimize the relation between the arch requires an extended clinical and in-home trial over a
patients who want veneers or other esthetic restora resin material (Unifol, Perident). The isolating mater es, they can be made on the mock-up. The clinician number of days. The changes can be discussed with
tive treatment, when new shapes and sizes and a ial must be applied to the sites not involved in the can also use the mock-up to assess the shapes of the the patient after 1 week, by which time the patient
new volume of the teeth must be designed and fabrication of the mock-up as well, to facilitate its teeth and the patient's expression, as well as the should have become more accustomed to the new
approved by the patient.>6 The patient's input is extraction without damaging the plaster cast. occlusion, before initiating treatment in the oral cav smile and dental expression. Tooth preparation
important to avoid any misunderstandings if small Finally, the series of casts representing the initial ity (Figs 8·22 to 8-25). should not be initiated until after the patient has
changes are needed based on the information ob case, the waxup, and the mock-up are forwarded to given approval.
tained from the diagnostic mock-up. the clinician (Figs 8-s to 8-7) for use in explaining to Surgical mock-up Preliminay tooth preparation for the mock-up is
Two implementation techniques to prepare the the patient the various stages that have been com An acrylic resin mock-up that lengthens the crowns sometimes necessay to reduce the original volume of
mock-up are described: a clinical or direct mock-up, pleted (Figs 8·8 and 8-9). and modifies the gingival contours can be used for a tooth (eg, when correcting tooth position without
and a technical or indirect mock-up. cases in which treatment requires the alignment and performing orthodontic treatment). Such preparation
Orthodontic mock-up optimal positioning of the gingival contours. With the creates the minimum amount of space needed to intro
Direct or clinical diagnostic mock-up An orthodontic mock-up can be placed directly i n the mock-up inserted in the oral cavity, the clinician can duce the mock-up, which thereafter will also act as the
A silicone index is molded via condensation directly patient's mouth with the teeth in their original posi use an indelible marker to mark the modifications on irst provisional restoration once it has been aligned.
on the diagnostic waxup (Zetalabor, Zermack) and tion, prior to any orthodontic displacement. It allows the gingival potion of the cast, thus making the mock· Esthetically, however, the appearance of a diag
then immediately transferred to the dental office. The the patient to understand the restorative treatment up useful for intra-operative surgery (see Fig 8-21). nostic mock-up is inadequate when compared with a
clinician fills the silicone index with autopolymerizing that is planned and appreciate the importance of the In general, the diagnostic mock-up enables the stratified provisional restoration that offers the
resin and then positions it inside the patient's mouth preprosthetic orthodontic treatment. patient to evaluate the proposed restorative treat· patient a clearer idea of the definitive restoration and
ment over a period of time. Patients frequently are is distinctly more comfortable in terms of both func- .
241
CHAPTER 8
directly over the teeth involved in the restoration, . The technique consists of adapting the wax uncomfortable with the look and feel of the new
.. information to the dental technician to use in defin
which have been isolated using either petroleum jelly veneers (obtained from the silicone casting molded tooth dimensions when the diagnostic mock-up is
ing the tooth shape of the provisional restoration.
or liquid soap (Figs 8·1 to 8-4). The contours of the on the waxup) on a new cast duplicated from the inserted for the first time. This reaction is both nor
In the authors' practice, a distinction is made be
tween different types of provisional elements: resin mock-up are trimmed of all excess material, and master cast. A silicone index, molded on the new wax mal and understandable since the patient's dental
then it is given to the patient to evaluate at home. veneers, is filled with resin and pressed onto anoth· expression and tooth shape developed gradually over
er cast duplicated from the master cast to obtain the many years. Therefore, it is better to make small pro
• Mock-up
• First-generation shell or prosthesis I n direct or technical mock-up orthodontic mock-up (Figs 8-10 to 8-16). gressive corrections to the length and shape of the
• Second-generation or adapted prosthesis The indirect mock-up technique is undertaken in the teeth in order to minimize the patient's anxiety and
laboratory using two study casts, one made of stone Crown diagnostic mock-up stress, which can lead to a refusal to continue with
and the other of silicone duplication material (Elite A crown-lengthening mock-up renects the planned the treatment.
Mock-up
Double, Zhermack). The diagnostic waxup is applied dimensions of the restored teeth, which can be espe Sometimes the patient's first impression is nega
By t h e term mock-up w e refer to a very t h i n clinical to the first (stone) cast, which is then used by the cially valuable for cases in which a design for reshap tive. When this happens, the clinician must try to
aid that is generally made of acrylic resin and that dental technician to fabricate a mold using extra ing and lengthening the teeth must be completed understand the patient's reaction and then proceed
incorporates each of the new clinical parameters hard (85 shores) silicone (Zetalabor). This silicone before tooth preparation, then the provisional restora to make the necessay adjustments without showing
established by the diagnostic waxup. In practice, this index is later filled with acylic resin and placed tion is immediately executed (Figs 8-17 to 8-20). this to the patient. Above all, the patient should not
negative copy of the diagnostic waxup also serves as directly on the second (silicone) cast, thus producing The acrylic resin mock-up is inserted in the mouth be given the mock-up for in-home analysis until the
an accurate reproduction of it, thus offering the great the mock-up. Inert wax (Schuler Dental) is applied to over the teeth involved in the prosthetic restoration appropriate changes have been made. Through each
advantage of showing the rehabilitation treatment the teeth involved in the restoration to facilitate to allow the clinician to check the occlusion, which phase of treatment, the patient must be informed
integrated in the overall esthetic and functional con removal of the acrylic mock-up. The entire site would have been modified in the previous phase of about all changes that are made, and the clinician
text directly on the patient. The mock-up can serve involved in the provisional restoration with the treatment (Fig 8-21). When occlusal adjustments are must be aware that subjective esthetic evaluation
as an important means of analysis and testing in acrylic resin must be further isolated with a plaster necessay to optimize the relation between the arch requires an extended clinical and in-home trial over a
patients who want veneers or other esthetic restora resin material (Unifol, Perident). The isolating mater es, they can be made on the mock-up. The clinician number of days. The changes can be discussed with
tive treatment, when new shapes and sizes and a ial must be applied to the sites not involved in the can also use the mock-up to assess the shapes of the the patient after 1 week, by which time the patient
new volume of the teeth must be designed and fabrication of the mock-up as well, to facilitate its teeth and the patient's expression, as well as the should have become more accustomed to the new
approved by the patient.>6 The patient's input is extraction without damaging the plaster cast. occlusion, before initiating treatment in the oral cav smile and dental expression. Tooth preparation
important to avoid any misunderstandings if small Finally, the series of casts representing the initial ity (Figs 8·22 to 8-25). should not be initiated until after the patient has
changes are needed based on the information ob case, the waxup, and the mock-up are forwarded to given approval.
tained from the diagnostic mock-up. the clinician (Figs 8-s to 8-7) for use in explaining to Surgical mock-up Preliminay tooth preparation for the mock-up is
Two implementation techniques to prepare the the patient the various stages that have been com An acrylic resin mock-up that lengthens the crowns sometimes necessay to reduce the original volume of
mock-up are described: a clinical or direct mock-up, pleted (Figs 8·8 and 8-9). and modifies the gingival contours can be used for a tooth (eg, when correcting tooth position without
and a technical or indirect mock-up. cases in which treatment requires the alignment and performing orthodontic treatment). Such preparation
Orthodontic mock-up optimal positioning of the gingival contours. With the creates the minimum amount of space needed to intro
Direct or clinical diagnostic mock-up An orthodontic mock-up can be placed directly i n the mock-up inserted in the oral cavity, the clinician can duce the mock-up, which thereafter will also act as the
A silicone index is molded via condensation directly patient's mouth with the teeth in their original posi use an indelible marker to mark the modifications on irst provisional restoration once it has been aligned.
on the diagnostic waxup (Zetalabor, Zermack) and tion, prior to any orthodontic displacement. It allows the gingival potion of the cast, thus making the mock· Esthetically, however, the appearance of a diag
then immediately transferred to the dental office. The the patient to understand the restorative treatment up useful for intra-operative surgery (see Fig 8-21). nostic mock-up is inadequate when compared with a
clinician fills the silicone index with autopolymerizing that is planned and appreciate the importance of the In general, the diagnostic mock-up enables the stratified provisional restoration that offers the
resin and then positions it inside the patient's mouth preprosthetic orthodontic treatment. patient to evaluate the proposed restorative treat· patient a clearer idea of the definitive restoration and
ment over a period of time. Patients frequently are is distinctly more comfortable in terms of both func- .
241
CHr i :£
Fig 8-5 Study cast of the initial situation created using the technique described in chapter l. This cast provides the technician with a clear and Fig 8-11 Wax up showing new anatomy and positioning. It is important to plan the correct spacing of teeth to achieve satisfactory integration
immediate view of the treatment result. Fig 8-6 Diagnostic waxup an the duplicate study cast. It is important to consider bath the preoperative of the restorative treatment in complex esthetic cases. Fig 8-12 Wax up placed directly an the duplicate cast used to create the acrylic resin
anatomy of the case and various treatment options. Fig 8-7 Technical diagnostic mack-up an the second cast obtained from the study cast dupli mock-up. This phase is crucial far determining the patient's acceptance of the treatment plan and above all the esthetic success of the pro
cate. With the indirect technique. the laboratory has the opportunity to use the duplicates of the master study cast and provide the clinician with visional. Fig 8-13 Orthodontic diagnostic mack-up finished and polished by hand and ready to be inserted in the oral cavity. Fig 8-14 Mack-up
the fi01shed mack-up an a new cast. Fig 8-8 Patient's smile before treatment. Fig 8 - 9 The mack-up. implemented in the laboratory on the diag inserted in the patient's mouth. This step demonstrates to the patient the need far and benefits of orthodontic treatment. Fig 8-15 Patient's
nostic waxup. is inserted directly an the natural dentition to evaluate the parameters established in the planning phase before any procedures smile before treatment. The significant dental asymmetry in relation to the midline of the face is evident. Fig 8-16 Smile after insertion of the
are begun. The changed dental anatomy and dentagingival relationship that would be achieved by the planned treatment can be easily assessed acrylic resin mock-up aver the existing prosthetic restoration.
'" this way. Fig 8-10 Initial clinical case in wh1ch the teeth need to be shifted to the left in order to achieve mare optimal spacing.
2
CHr i :£
Fig 8-5 Study cast of the initial situation created using the technique described in chapter l. This cast provides the technician with a clear and Fig 8-11 Wax up showing new anatomy and positioning. It is important to plan the correct spacing of teeth to achieve satisfactory integration
immediate view of the treatment result. Fig 8-6 Diagnostic waxup an the duplicate study cast. It is important to consider bath the preoperative of the restorative treatment in complex esthetic cases. Fig 8-12 Wax up placed directly an the duplicate cast used to create the acrylic resin
anatomy of the case and various treatment options. Fig 8-7 Technical diagnostic mack-up an the second cast obtained from the study cast dupli mock-up. This phase is crucial far determining the patient's acceptance of the treatment plan and above all the esthetic success of the pro
cate. With the indirect technique. the laboratory has the opportunity to use the duplicates of the master study cast and provide the clinician with visional. Fig 8-13 Orthodontic diagnostic mack-up finished and polished by hand and ready to be inserted in the oral cavity. Fig 8-14 Mack-up
the fi01shed mack-up an a new cast. Fig 8-8 Patient's smile before treatment. Fig 8 - 9 The mack-up. implemented in the laboratory on the diag inserted in the patient's mouth. This step demonstrates to the patient the need far and benefits of orthodontic treatment. Fig 8-15 Patient's
nostic waxup. is inserted directly an the natural dentition to evaluate the parameters established in the planning phase before any procedures smile before treatment. The significant dental asymmetry in relation to the midline of the face is evident. Fig 8-16 Smile after insertion of the
are begun. The changed dental anatomy and dentagingival relationship that would be achieved by the planned treatment can be easily assessed acrylic resin mock-up aver the existing prosthetic restoration.
'" this way. Fig 8-10 Initial clinical case in wh1ch the teeth need to be shifted to the left in order to achieve mare optimal spacing.
2
C1 , ·
Fig 8-17 Clinical case requiring crown lengthening to treat the worn natural dentition of a bruxing patient Fig 8-18 Casts on an articulator
showing the required vertical dimension. based on the occlusal record provided by the clinician. Fig 8-1 g Maxillary and mandibular waxups
on an articulator. Treatment is focused on the redefinition of the tooth anatomy and function, especially in terms of occlusal guidance and
disclusion in protrusion and right and left lateral movements. Fig 8-20 Maxillary and mandibular mock-ups on the casts. It is sound practice
also to work on the master cast duplicates in order to obtain these removable provisional elements again at a later time. Fig 8-21 Mock-up
inserted in the oral cavity. At this point it is possible to evaluate the established parameters and the occlusal record by performi n g phonetic
and esthetic tests. Fig 8-22 Patient's smile before treatment Note the significant loss of vertical height with the marked wear of the o cclusal
surfaces and the resulting shape and composition of the dental anatomy. Fig 8-23 Patient's smile with the mock-up placed in the oral cavity.
It is advisable to take photographs to allow re-evaluation of the case in regards to esthetic appearance without the patient being present
Fig 8-24 Appearance of perioral structures before treatment Fig 8-25 Change in perioral structures with the mock-up inserted.
25
C1 , ·
Fig 8-17 Clinical case requiring crown lengthening to treat the worn natural dentition of a bruxing patient Fig 8-18 Casts on an articulator
showing the required vertical dimension. based on the occlusal record provided by the clinician. Fig 8-1 g Maxillary and mandibular waxups
on an articulator. Treatment is focused on the redefinition of the tooth anatomy and function, especially in terms of occlusal guidance and
disclusion in protrusion and right and left lateral movements. Fig 8-20 Maxillary and mandibular mock-ups on the casts. It is sound practice
also to work on the master cast duplicates in order to obtain these removable provisional elements again at a later time. Fig 8-21 Mock-up
inserted in the oral cavity. At this point it is possible to evaluate the established parameters and the occlusal record by performi n g phonetic
and esthetic tests. Fig 8-22 Patient's smile before treatment Note the significant loss of vertical height with the marked wear of the o cclusal
surfaces and the resulting shape and composition of the dental anatomy. Fig 8-23 Patient's smile with the mock-up placed in the oral cavity.
It is advisable to take photographs to allow re-evaluation of the case in regards to esthetic appearance without the patient being present
Fig 8-24 Appearance of perioral structures before treatment Fig 8-25 Change in perioral structures with the mock-up inserted.
25
CHAPTER 8
. tion and esthetics. Conversely, the mock-up repre· preparation, and the third will be used as a matrix for . The dental technician pours the acrylic resin The indirect technique can strengthen cooperation
sents the most conservative solution with regard to molding the acrylic resin over the tooth preparations. inside the silicone matrix and applies it directly to between the clinician and the technician. Indeed, with
the patient's health and the most efective means of The provisional restoration is monochromatic if the duplicate cast. After it is removed, the dentin this technique the technician provides the diagnostic
communicating the new parameters of the restora· dentin materials alone are used (Fig 8·26). and strat· material is applied at a pressure of 4 bars and poly support of a positional silicone index (Fig 8-40),
tion, since it is positioned directly over the existing ified if the dentin-enamel technique is adopted. In merized at a temperature between so0( and 6o0( for which is useful to avoid damaging work executed in
dental situation. the latter case, the clinician fabricates a shell using 3 to s min utes'-9 while the silicone index is held in the laboratory and as a clinical reference point for
The diagnostic commitment of making a stratified dentin-type acrylic resin on teeth isolated with petro· position using elastic bands. positioning the provisional prosthesis. This technique
provisional prosthesis as well may initially appear leum jelly or liquid soap. After allowing adequate A new silicone index is now made with the dentin also prevents shape-related distortions of the provi
excessive, but it offers numerous advantages: It pro· time for complete polymerization, the clinician layer in place and sectioned horizontally to monitor sional prosthesis or incorrect positioning during the
vides the best guarantee for the outcome of the removes the prosthesis from the mouth and roughs the reduction of the dentin material so as to ensure alignment process (Figs 8-41 to 8·46).
treatment, reconfirms the patient's trust, avoids mis out the incisal, buccal, and palatal surfaces so as to adequate space for molding the enamel-type resin. A
understandings, and prevents the unpleasant conse· allow room for a second application, this time using photopolymerizing adhesive (Connector) is applied to Indirect technique on the s i licone index
quences of inadequate treatment. enamel-type resin (Figs 8-27 and 8-28). the reduced dentin layer, and setting material can be As with the other procedures for creating provisional
The prepared dentin provisional restoration is introduced at the incisal edge and then polymerized restorations, the starting point is the diagnostic
then repositioned in the oral cavity, and a silicone with a special halogen lamp or light-curing unit for 2 waxup, which ensures that the treatment plan meets
First-generation provisional restoration
matrix, this time with an enamel-type resin mixture minutes, to imitate the incisal efects (Fig 8·38). the patient's requests.
The shell-fabricated prosthesis is a first-generation consisting of So% enamel and 20% transparent Surface characterizations are not necessary on the The silicone index made from the waxup acts as a
provisional restoration that is adapted and intro material, is molded to the dentin layer (Figs 8·29 to middle and cervical third, since this provisional pros· matrix for the dentin-type acrylic resin. It is filled with
duced into the oral cavity immediately after the old 8·31). Ater the dentin-enamel provisional restoration thesis will be handled by the clinician and is subject resin and polymerized to create a small resin cast
restoration is removed and preliminary tooth prepa has hardened, it is removed from the oral cavity and to alignment adjustment and other modifications. (Fig 8-47). This resin cast is then used to make a new
ration has been completed. The first-generation pro trimmed using suitable disks and burs (Figs 8·32 to Finally, the enamel mixture is molded directly on the silicone index, which is sectioned for monitoring the
visional enhances the patient's oral esthetics, pro 8-34). To improve precision, the clinician must some· hardened dentin at a pressure of 4 bars and poly· reduction of the incisal edges and buccal surfaces of
vides the clinician with diagnostic information, and times roughen the inside surface around the cevical merized at a temperature between so°C and 6o°C for the dentin-type material (Fig 8·48). Intermediate pho
conditions the soft tissues. It can be developed margin, moisten this surface with a photopolymeriz s minutes, using the same silicone matrix that was topolymerizing shade modifiers (Artglass (reactive,
using a direct technique in the oral cavity, an indirect ing adhesive (Connector, Heraeus Kulzer), and realign used for the dentin layer. Heraeus Kulzer) can be added once the surface has
technique on the plaster cast, or an indirect tech· the provisional restoration using auto- and pho· The provisional prosthesis is removed from the been covered with a specific adhesive. The enamel
nique on the silicone index. topolymerizing resins (Unifast, GC). plaster cast and fitted on the master cast, which has type layer is molded onto the dentin-type layer, again
been previously prepared by the dental technician using the same silicone matrix used previously (Figs
Direct technique in the oral cavtty Indirect technique on the stone cast (Fig 8-39). A new silicone index is made with the 8·49 and B· so).
The laboratoy prepares a master cast, which is later The indirect technique is performed in the laboratory, occlusal stops on the adjacent teeth to verify that The cast is roughed out using laboratory burs
duplicated for the diagnostic waxup (see chapter 1). and all of the procedures are executed using a sili· the alignment in the oral cavity corresponds to the after polymerization has been completed, removing
After the waxup has been completed, a number of cone matrix. After completing the diagnostic waxup, same position on the plaster cast. If the alignment is the adjacent teeth and leaving intact only the teeth
silicone indices are prepared at a pressure of 4 bars the dental technician undertakes the preliminary not identical, the clinician needs to adjust the pre involved in the restoration. The provisional restora
to ensure the highest possible accuracy in reproduc tooth preparation on the plaster cast. The preparation pared tooth inside the mouth or reduce the provi tion is then trimmed and polished (Fig B· s 1). Because
ing the details of the waxup. is monitored using a horizontally sectioned silicone sional prosthesis at points of friction or in areas of it is repositioned inside the mold, the small resin
The clinician eventually receives the study cast. a index. This cast with prepared teeth is then duplicat- tissue compression in edentulous sites. The provi cast can be hollowed out without damaging the cer
duplicate cast on which the diagnostic waxup has ed to create a new plaster cast on which the provi sional shell must maintain the same position and vical limits (Figs B-s2 and B· s3).
been made, and at least three silicone indices. Two of sional prosthesis can be created (Figs 8·3s to 8-37). . parameters when it is transferred from the plaster The silicone matrix originally used to cast the
the indices will be sectioned for use during tooth cast to the intraoral site. resin is sectioned horizontally, and the provisional .
247
CHAPTER 8
. tion and esthetics. Conversely, the mock-up repre· preparation, and the third will be used as a matrix for . The dental technician pours the acrylic resin The indirect technique can strengthen cooperation
sents the most conservative solution with regard to molding the acrylic resin over the tooth preparations. inside the silicone matrix and applies it directly to between the clinician and the technician. Indeed, with
the patient's health and the most efective means of The provisional restoration is monochromatic if the duplicate cast. After it is removed, the dentin this technique the technician provides the diagnostic
communicating the new parameters of the restora· dentin materials alone are used (Fig 8·26). and strat· material is applied at a pressure of 4 bars and poly support of a positional silicone index (Fig 8-40),
tion, since it is positioned directly over the existing ified if the dentin-enamel technique is adopted. In merized at a temperature between so0( and 6o0( for which is useful to avoid damaging work executed in
dental situation. the latter case, the clinician fabricates a shell using 3 to s min utes'-9 while the silicone index is held in the laboratory and as a clinical reference point for
The diagnostic commitment of making a stratified dentin-type acrylic resin on teeth isolated with petro· position using elastic bands. positioning the provisional prosthesis. This technique
provisional prosthesis as well may initially appear leum jelly or liquid soap. After allowing adequate A new silicone index is now made with the dentin also prevents shape-related distortions of the provi
excessive, but it offers numerous advantages: It pro· time for complete polymerization, the clinician layer in place and sectioned horizontally to monitor sional prosthesis or incorrect positioning during the
vides the best guarantee for the outcome of the removes the prosthesis from the mouth and roughs the reduction of the dentin material so as to ensure alignment process (Figs 8-41 to 8·46).
treatment, reconfirms the patient's trust, avoids mis out the incisal, buccal, and palatal surfaces so as to adequate space for molding the enamel-type resin. A
understandings, and prevents the unpleasant conse· allow room for a second application, this time using photopolymerizing adhesive (Connector) is applied to Indirect technique on the s i licone index
quences of inadequate treatment. enamel-type resin (Figs 8-27 and 8-28). the reduced dentin layer, and setting material can be As with the other procedures for creating provisional
The prepared dentin provisional restoration is introduced at the incisal edge and then polymerized restorations, the starting point is the diagnostic
then repositioned in the oral cavity, and a silicone with a special halogen lamp or light-curing unit for 2 waxup, which ensures that the treatment plan meets
First-generation provisional restoration
matrix, this time with an enamel-type resin mixture minutes, to imitate the incisal efects (Fig 8·38). the patient's requests.
The shell-fabricated prosthesis is a first-generation consisting of So% enamel and 20% transparent Surface characterizations are not necessary on the The silicone index made from the waxup acts as a
provisional restoration that is adapted and intro material, is molded to the dentin layer (Figs 8·29 to middle and cervical third, since this provisional pros· matrix for the dentin-type acrylic resin. It is filled with
duced into the oral cavity immediately after the old 8·31). Ater the dentin-enamel provisional restoration thesis will be handled by the clinician and is subject resin and polymerized to create a small resin cast
restoration is removed and preliminary tooth prepa has hardened, it is removed from the oral cavity and to alignment adjustment and other modifications. (Fig 8-47). This resin cast is then used to make a new
ration has been completed. The first-generation pro trimmed using suitable disks and burs (Figs 8·32 to Finally, the enamel mixture is molded directly on the silicone index, which is sectioned for monitoring the
visional enhances the patient's oral esthetics, pro 8-34). To improve precision, the clinician must some· hardened dentin at a pressure of 4 bars and poly· reduction of the incisal edges and buccal surfaces of
vides the clinician with diagnostic information, and times roughen the inside surface around the cevical merized at a temperature between so°C and 6o°C for the dentin-type material (Fig 8·48). Intermediate pho
conditions the soft tissues. It can be developed margin, moisten this surface with a photopolymeriz s minutes, using the same silicone matrix that was topolymerizing shade modifiers (Artglass (reactive,
using a direct technique in the oral cavity, an indirect ing adhesive (Connector, Heraeus Kulzer), and realign used for the dentin layer. Heraeus Kulzer) can be added once the surface has
technique on the plaster cast, or an indirect tech· the provisional restoration using auto- and pho· The provisional prosthesis is removed from the been covered with a specific adhesive. The enamel
nique on the silicone index. topolymerizing resins (Unifast, GC). plaster cast and fitted on the master cast, which has type layer is molded onto the dentin-type layer, again
been previously prepared by the dental technician using the same silicone matrix used previously (Figs
Direct technique in the oral cavtty Indirect technique on the stone cast (Fig 8-39). A new silicone index is made with the 8·49 and B· so).
The laboratoy prepares a master cast, which is later The indirect technique is performed in the laboratory, occlusal stops on the adjacent teeth to verify that The cast is roughed out using laboratory burs
duplicated for the diagnostic waxup (see chapter 1). and all of the procedures are executed using a sili· the alignment in the oral cavity corresponds to the after polymerization has been completed, removing
After the waxup has been completed, a number of cone matrix. After completing the diagnostic waxup, same position on the plaster cast. If the alignment is the adjacent teeth and leaving intact only the teeth
silicone indices are prepared at a pressure of 4 bars the dental technician undertakes the preliminary not identical, the clinician needs to adjust the pre involved in the restoration. The provisional restora
to ensure the highest possible accuracy in reproduc tooth preparation on the plaster cast. The preparation pared tooth inside the mouth or reduce the provi tion is then trimmed and polished (Fig B· s 1). Because
ing the details of the waxup. is monitored using a horizontally sectioned silicone sional prosthesis at points of friction or in areas of it is repositioned inside the mold, the small resin
The clinician eventually receives the study cast. a index. This cast with prepared teeth is then duplicat- tissue compression in edentulous sites. The provi cast can be hollowed out without damaging the cer
duplicate cast on which the diagnostic waxup has ed to create a new plaster cast on which the provi sional shell must maintain the same position and vical limits (Figs B-s2 and B· s3).
been made, and at least three silicone indices. Two of sional prosthesis can be created (Figs 8·3s to 8-37). . parameters when it is transferred from the plaster The silicone matrix originally used to cast the
the indices will be sectioned for use during tooth cast to the intraoral site. resin is sectioned horizontally, and the provisional .
247
CH Pll R S
Fig 8-26 Prepared dentin provisional reslorat1on placed in the oral cavity. At this point the provisional can be trimmed and polished imme Fig 8-30 The clinician has plated the chromatic characterizations on the dentin surface. The colors are polymerized with a special halogen
diately for a monochromatic result if the esthetic needs and expectations of the case are not high. Fig 8-27 For cases in which esthetics light-emitting lamp. Fig 8-31 Molding phase of enamel-type acrylic resin. Fig 8-32 The provisional has been finished. This phase is always
are important. it is necessary to continue the treatment by reducing the dentin layer to create spate for the enamel resin and photo completed using diamond or tungsten carbide burs. Fig 8-33 Polishing has been completed and lhe acrylic resin provisional cemented in
polymeriZing colors. when applicable. Here. the dentin has been prepared to recreate the mamelons and other dentinal structures and the mouth. Fig 8-34 Profile view of the provisional at high magnification under the stereomicroscope.
reduced to a thin layer in the incisal third to a thieve the optimal value. Fig 8-28 The spate available for the enamel resin and photopoly
meming colors is checked. Fig 8-2g The incisal gel is plated 1n preparation for the introduction of chromatic characterizations.
249
CH Pll R S
Fig 8-26 Prepared dentin provisional reslorat1on placed in the oral cavity. At this point the provisional can be trimmed and polished imme Fig 8-30 The clinician has plated the chromatic characterizations on the dentin surface. The colors are polymerized with a special halogen
diately for a monochromatic result if the esthetic needs and expectations of the case are not high. Fig 8-27 For cases in which esthetics light-emitting lamp. Fig 8-31 Molding phase of enamel-type acrylic resin. Fig 8-32 The provisional has been finished. This phase is always
are important. it is necessary to continue the treatment by reducing the dentin layer to create spate for the enamel resin and photo completed using diamond or tungsten carbide burs. Fig 8-33 Polishing has been completed and lhe acrylic resin provisional cemented in
polymeriZing colors. when applicable. Here. the dentin has been prepared to recreate the mamelons and other dentinal structures and the mouth. Fig 8-34 Profile view of the provisional at high magnification under the stereomicroscope.
reduced to a thin layer in the incisal third to a thieve the optimal value. Fig 8-28 The spate available for the enamel resin and photopoly
meming colors is checked. Fig 8-2g The incisal gel is plated 1n preparation for the introduction of chromatic characterizations.
249
Fig 8-35 Formalton of several l -mm-deep grooves on the plasler cast Ftg 8-36 The available space for acrylic resin is checked using a sec Fig 8-41 Preoperattve view of a clintcal case tn which the existtng metal-ceramtc crowns on the central tncisors are dtSproporttonate to the
tioned siltcone index obtained from the dtagnostic waxup Fig 8-37 Preliminary tooth preparation is completed on the study cast duplicate. adjacent teeth. Fig 8-42 The provisional prosthesis was implemented ustng the indirect techntque and then aligned in the oral cavity using the
whtch IS ready to be reduplicated The proviSional prosthesis will then be created on this new plaster cast. Fig 8-38 The incisal photopolymer silicone index. Fig 8-43 Smtle before treatment. Fig 8-44 Smtle with provisional tn place The central incisors are now in harmony with the
iztng colors have been added over the dentin material. Fig 8-3g Promional finished and positioned on the cast. An extra-hard silicone index adjacent teeth. Fig 8-45 Full-face pretreatment view of pattent. Fig 8-46 Patient's appearance following cementation of the provisional.
will be implemented on the provisional while posittoned on the plaster cast. providing occlusal stops on the posterior sector. This will enable
the cltntctan to transfer the provistonal to the patient's mouth white maintaining the same positiOn as on the plaster cast. Fig 8-40 Provisional
tnserted tn the mouth ustng the siltcone index
251
Fig 8-35 Formalton of several l -mm-deep grooves on the plasler cast Ftg 8-36 The available space for acrylic resin is checked using a sec Fig 8-41 Preoperattve view of a clintcal case tn which the existtng metal-ceramtc crowns on the central tncisors are dtSproporttonate to the
tioned siltcone index obtained from the dtagnostic waxup Fig 8-37 Preliminary tooth preparation is completed on the study cast duplicate. adjacent teeth. Fig 8-42 The provisional prosthesis was implemented ustng the indirect techntque and then aligned in the oral cavity using the
whtch IS ready to be reduplicated The proviSional prosthesis will then be created on this new plaster cast. Fig 8-38 The incisal photopolymer silicone index. Fig 8-43 Smtle before treatment. Fig 8-44 Smtle with provisional tn place The central incisors are now in harmony with the
iztng colors have been added over the dentin material. Fig 8-3g Promional finished and positioned on the cast. An extra-hard silicone index adjacent teeth. Fig 8-45 Full-face pretreatment view of pattent. Fig 8-46 Patient's appearance following cementation of the provisional.
will be implemented on the provisional while posittoned on the plaster cast. providing occlusal stops on the posterior sector. This will enable
the cltntctan to transfer the provistonal to the patient's mouth white maintaining the same positiOn as on the plaster cast. Fig 8-40 Provisional
tnserted tn the mouth ustng the siltcone index
251
CHAPTER 8
. prosthesis is introduced into the mouth. By using the rations during the cast construction phase with the . then evaluated using the silicone index on the sec Another silicone index is created so that the
actual matrix, the clinician can more easily determine removable dies and the gingiva. ond stone cast that was fabricated especially for this reduction of the dentin layer can be carefully moni
the exact position of the provisional prosthesis The duplicate dies are treated with a setting solu purpose (Figs 8-6o and 8-61). The dies are bonded tored (Figs 8-70 to 8-72). The buccolingual thickness
when it is positioned in the oral cavity (Figs 8·54 tion (Margidur, Benzer Dental) that penetrates the at the cervical margin of the cast using adhesive of the dentin layer must have an incisal edge that is
and 8-55). porous plaster without increasing in thickness. After wax, which is also used to bond the silicone index significantly though not completely reduced, as this
their exterior surfaces are treated with soft wax. the to the dies. The surfaces of the dies protruding from would greatly compromise the value of the final
dies are reintroduced into the impression with a lit the upper part of the cast are isolated with a very result (Fig 8-73). A bonding adhesive (Connector) is
Second-generation provisional
tle pressure. Cyanoacrylate is added to the head of thin layer of inert wax, and then a larger quantity of applied to ensure an enhanced bond with the pho
prosthesis
each die, and the dies are then bonded. inert wax is applied to the base of the dies to iden topolymerizing colors (Artglass (reactive) added to
Modern practitioners have long abandoned the tra· The dies are bonded at the cervical margin with tify where they are located during the squaring oper the surface (Fig 8·74). The second silicone index is
ditional practice of using a mediocre provisional adhesive wax (Kiebewachs, Gebdi), which cements ation. The two parts previously moistened are then used to ensure that suficient space is left for the
prosthesis to be replaced with an improved perma· them during casting (Fig 8-58) and enables them to fixated with plaster and, once set, excess portions enamel-type material to be added and polymerized.
nent ceramic prosthesis. '0 be removed once the plaster has set and the bond are trimmed to square the entire cast. The sealant Once the enamel-type material is molded using
The stratified provisional prosthesis involves the ed dies have been reintroduced inside the impres wax is removed from the base using a heat-generat the same matrix, the restoration is detached from
application of a technique similar to that used to sion. For optimal results, this plaster should be in a ing machine so that the dies can be removed (Figs the plaster cast, which can be discarded, and adapt·
create the indirect first-generation provisional slightly more liquified form than usual to allow 8-62 to 8-66). ed to the working cast with the aid of contact·
restoration, requiring either a stone or resin cast, slight vibrations to be applied during the casting With its removable dies, this cast provides the detecting powder (Figs 8-75 to 8-78). The result is
except that the pigmentation also is applied to the process. means to condition the soft tissues and assess the a stratified provisional restoration that can be
middle and cervical third of the restorations. For this phase, the technician has two options for tooth morphology, since the gingival information is mechanically trimmed and polished without loss of
producing the master cast: The cast can be poured included. A duplicate of this cast will be needed for its color characteristics. It can be used to evaluate
Stone casts as a single process, thus instantly creating the base, molding the resin. the shape, length, position, and characterizations
The essential diferences in this procedure compared or a double-pouring process can be used, requiring In summary, the sequence is as follows: (chroma, value, and color) of the restoration, as well
with the techniques described earlier are ) the two separate pours. The latter technique involves a as for gingival conditioning (Figs 8-79 to 8-82).
teeth have already been prepared, and (2) the soft first pour to cover the dies and a second pour to • Master dies The diagnostic commitment of the prosthetic team
tissues, which for several weeks supported the first create a cast in a rubber base. Both casts are • Master dies duplicated using silicone is reconfirmed in vivo with the provisional prosthesis
generation provisional prosthesis, have adapted to removed from the im pression after the plaster has • Duplicated dies that reproduces the shape of the waxup, or some
the new situation. set (about 45 minutes) and squared separately • Fixed dies used to prepare a control silicone key detail of the dental anatomy is changed by examin
For complex cases and others that the clinician using the cast-squaring tool. • Dies originating from the duplication inserted in ing the slides and a plaster model originating from
deems appropriate, a second-generation provisional The dies are removed individually with the use of the impression for the Geller model the first provisional prosthesis (Figs 8-83 to 8·86).
restoration should be prepared in the laboratoy on hot steam produced by a steam generator to melt • Geller cast The second-generation provisional prosthesis is
a precise elastomeric impression obtained ater gin the adhesive wax sealant. The technician must take a conversion of the monochromatic waxup in poly
gival retraction. The impression should have perfect care to clean the die channels before any subse A new waxup is prepared on the duplicate work chromatic resin. For major restorative treatments,
ly discernible cervical margins and be cast using quent use to optimize the positioning of the remov ing cast using the silicone index of the study cast this represents the most important diagnostic stage,
class IV plaster to obtain the master tooth prepara able dies. Care should also be taken to highlight the waxup as a guide (Figs 8-67 and 8-68). A silicone and, though it is provisional, it conditions the soft
tions. These are trimmed to give them a carrot-like perimeter of the arch and the channel position when matrix is molded on the new waxup, set under a tissues and demonstrates esthetic quality similar
shape and subsequently duplicated (Figs 8·56 and the casts are matched, so that holes can later be pressure of 3 to 4 bars (Zeta labor), and used to adapt to that of the definitive restorative treatment"-'5
8-57). The same elastomeric impression is used to prepared to accommodate the protruding parts of the dentin-type material (New Outline, Anaxdent) on (Figs 8-87 to 8-92). Additionally, this prosthesis gives
prepare another cast; the silicone index made on this the dies (Fig 8-59). The dies will be reinserted into the duplicate stone cast. The dentin layer is then the patient tangible evidence of the prosthetic team's
cast is used to check the position of the tooth prepa- the cast and then positioned; their exact position is . fired on the stone cast at 6o0U-9 (Fig 8-69). commitment to the work involved in the restorative .
252
CHAPTER 8
. prosthesis is introduced into the mouth. By using the rations during the cast construction phase with the . then evaluated using the silicone index on the sec Another silicone index is created so that the
actual matrix, the clinician can more easily determine removable dies and the gingiva. ond stone cast that was fabricated especially for this reduction of the dentin layer can be carefully moni
the exact position of the provisional prosthesis The duplicate dies are treated with a setting solu purpose (Figs 8-6o and 8-61). The dies are bonded tored (Figs 8-70 to 8-72). The buccolingual thickness
when it is positioned in the oral cavity (Figs 8·54 tion (Margidur, Benzer Dental) that penetrates the at the cervical margin of the cast using adhesive of the dentin layer must have an incisal edge that is
and 8-55). porous plaster without increasing in thickness. After wax, which is also used to bond the silicone index significantly though not completely reduced, as this
their exterior surfaces are treated with soft wax. the to the dies. The surfaces of the dies protruding from would greatly compromise the value of the final
dies are reintroduced into the impression with a lit the upper part of the cast are isolated with a very result (Fig 8-73). A bonding adhesive (Connector) is
Second-generation provisional
tle pressure. Cyanoacrylate is added to the head of thin layer of inert wax, and then a larger quantity of applied to ensure an enhanced bond with the pho
prosthesis
each die, and the dies are then bonded. inert wax is applied to the base of the dies to iden topolymerizing colors (Artglass (reactive) added to
Modern practitioners have long abandoned the tra· The dies are bonded at the cervical margin with tify where they are located during the squaring oper the surface (Fig 8·74). The second silicone index is
ditional practice of using a mediocre provisional adhesive wax (Kiebewachs, Gebdi), which cements ation. The two parts previously moistened are then used to ensure that suficient space is left for the
prosthesis to be replaced with an improved perma· them during casting (Fig 8-58) and enables them to fixated with plaster and, once set, excess portions enamel-type material to be added and polymerized.
nent ceramic prosthesis. '0 be removed once the plaster has set and the bond are trimmed to square the entire cast. The sealant Once the enamel-type material is molded using
The stratified provisional prosthesis involves the ed dies have been reintroduced inside the impres wax is removed from the base using a heat-generat the same matrix, the restoration is detached from
application of a technique similar to that used to sion. For optimal results, this plaster should be in a ing machine so that the dies can be removed (Figs the plaster cast, which can be discarded, and adapt·
create the indirect first-generation provisional slightly more liquified form than usual to allow 8-62 to 8-66). ed to the working cast with the aid of contact·
restoration, requiring either a stone or resin cast, slight vibrations to be applied during the casting With its removable dies, this cast provides the detecting powder (Figs 8-75 to 8-78). The result is
except that the pigmentation also is applied to the process. means to condition the soft tissues and assess the a stratified provisional restoration that can be
middle and cervical third of the restorations. For this phase, the technician has two options for tooth morphology, since the gingival information is mechanically trimmed and polished without loss of
producing the master cast: The cast can be poured included. A duplicate of this cast will be needed for its color characteristics. It can be used to evaluate
Stone casts as a single process, thus instantly creating the base, molding the resin. the shape, length, position, and characterizations
The essential diferences in this procedure compared or a double-pouring process can be used, requiring In summary, the sequence is as follows: (chroma, value, and color) of the restoration, as well
with the techniques described earlier are ) the two separate pours. The latter technique involves a as for gingival conditioning (Figs 8-79 to 8-82).
teeth have already been prepared, and (2) the soft first pour to cover the dies and a second pour to • Master dies The diagnostic commitment of the prosthetic team
tissues, which for several weeks supported the first create a cast in a rubber base. Both casts are • Master dies duplicated using silicone is reconfirmed in vivo with the provisional prosthesis
generation provisional prosthesis, have adapted to removed from the im pression after the plaster has • Duplicated dies that reproduces the shape of the waxup, or some
the new situation. set (about 45 minutes) and squared separately • Fixed dies used to prepare a control silicone key detail of the dental anatomy is changed by examin
For complex cases and others that the clinician using the cast-squaring tool. • Dies originating from the duplication inserted in ing the slides and a plaster model originating from
deems appropriate, a second-generation provisional The dies are removed individually with the use of the impression for the Geller model the first provisional prosthesis (Figs 8-83 to 8·86).
restoration should be prepared in the laboratoy on hot steam produced by a steam generator to melt • Geller cast The second-generation provisional prosthesis is
a precise elastomeric impression obtained ater gin the adhesive wax sealant. The technician must take a conversion of the monochromatic waxup in poly
gival retraction. The impression should have perfect care to clean the die channels before any subse A new waxup is prepared on the duplicate work chromatic resin. For major restorative treatments,
ly discernible cervical margins and be cast using quent use to optimize the positioning of the remov ing cast using the silicone index of the study cast this represents the most important diagnostic stage,
class IV plaster to obtain the master tooth prepara able dies. Care should also be taken to highlight the waxup as a guide (Figs 8-67 and 8-68). A silicone and, though it is provisional, it conditions the soft
tions. These are trimmed to give them a carrot-like perimeter of the arch and the channel position when matrix is molded on the new waxup, set under a tissues and demonstrates esthetic quality similar
shape and subsequently duplicated (Figs 8·56 and the casts are matched, so that holes can later be pressure of 3 to 4 bars (Zeta labor), and used to adapt to that of the definitive restorative treatment"-'5
8-57). The same elastomeric impression is used to prepared to accommodate the protruding parts of the dentin-type material (New Outline, Anaxdent) on (Figs 8-87 to 8-92). Additionally, this prosthesis gives
prepare another cast; the silicone index made on this the dies (Fig 8-59). The dies will be reinserted into the duplicate stone cast. The dentin layer is then the patient tangible evidence of the prosthetic team's
cast is used to check the position of the tooth prepa- the cast and then positioned; their exact position is . fired on the stone cast at 6o0U-9 (Fig 8-69). commitment to the work involved in the restorative .
252
Fig 8-47 Acrylic resin polymerized inside the silicone matrix and implemented on the diagnostic waxup. The acrylic material is baked at a tem Fig 8-53 Provisional inserted in the silicone index. It is advisable to section the silicone index horizontally to enable easy transfer of the pro
perature of 6o·c and at a pressure of 4 bars. Fig 8-48 Sectioned silicone index used to evaluate the space available for the enamel-type resin visional to the mouth for the alignment phase. Fig 8-54 Clinical try-in of the provisional with the help of the silicone index. Fig 8-55 Provisional
as the surface of the dentin-type resin is reduced. Fig 8-49 Dentin characterizations implemented using photopolymerizing colors. Fig 8-50 aligned and cemented in the oral cavity.
Enamel-type acrylic resin molded on the dentin base and subsequently polymerized at a pressure of 4 bars. Fig 8-51 Provisional after polish
ing on the buccal surfaces. Polishing is achieved using a number of micromotor-operated brushes or a laboratory cleaning machine. Fig 8-52
Provisional following rough1ng out of the internal portion using tungsten carbide burs of different diameters and shapes.
255
Fig 8-47 Acrylic resin polymerized inside the silicone matrix and implemented on the diagnostic waxup. The acrylic material is baked at a tem Fig 8-53 Provisional inserted in the silicone index. It is advisable to section the silicone index horizontally to enable easy transfer of the pro
perature of 6o·c and at a pressure of 4 bars. Fig 8-48 Sectioned silicone index used to evaluate the space available for the enamel-type resin visional to the mouth for the alignment phase. Fig 8-54 Clinical try-in of the provisional with the help of the silicone index. Fig 8-55 Provisional
as the surface of the dentin-type resin is reduced. Fig 8-49 Dentin characterizations implemented using photopolymerizing colors. Fig 8-50 aligned and cemented in the oral cavity.
Enamel-type acrylic resin molded on the dentin base and subsequently polymerized at a pressure of 4 bars. Fig 8-51 Provisional after polish
ing on the buccal surfaces. Polishing is achieved using a number of micromotor-operated brushes or a laboratory cleaning machine. Fig 8-52
Provisional following rough1ng out of the internal portion using tungsten carbide burs of different diameters and shapes.
255
Fig 8-56 Master tooth preparations created using a precise elastomeric impression and white class IV plaster. Fig 8-57 The master tooth Fig 8-62 The final section of dies is suitably waxed. and plaster is added over the entire surface. Fig 8-63 Plaster is then poured inside the
preparations are duplicated using 1,1 ratio dupliCation silicone. Both the silicone and plaster are treated using a vacuum at a pressure of 4 base trough and on all the retention grooves implemented on the surface. Fig 8-64 Contact positioning of the two parts using the same class
bars. Fig 8-58 Removable dies with special notches and grooves to guide reinsertion. These dies. which require a slightly tapered shape. are IV plaster but with a more liquid consistency. Fig 8-65 Frontal view of the finished and squared cast. Fig 8-66 O cclusal view of a sectioned cast
inserted inside the impression to be again subjected to casting. Fig 8-59 Dies reinserted in the cast. The base of the cast has a large trough detailing re. -insertion channels of the removable dies. Fig 8-6.7 Frontal view .of a Geller cast of the case. This type of sectioned cast highlights
to house the terminal projections of the removable dies. Retention grooves have been prepared on the adjoining parts. Fig 8-60 Silicone index the anatomiC charactenst1cs of the g1ng1val margm and prov1des a better VIeW of the dental anatomy and the dentogingival relationship. It is
positioned on the second stone cast. Fig 8-61 Silicone index transferred to the removable-die cast to check positioning. very difficult to create ceramic restorations without having the gingival tissues for reference.
27
Fig 8-56 Master tooth preparations created using a precise elastomeric impression and white class IV plaster. Fig 8-57 The master tooth Fig 8-62 The final section of dies is suitably waxed. and plaster is added over the entire surface. Fig 8-63 Plaster is then poured inside the
preparations are duplicated using 1,1 ratio dupliCation silicone. Both the silicone and plaster are treated using a vacuum at a pressure of 4 base trough and on all the retention grooves implemented on the surface. Fig 8-64 Contact positioning of the two parts using the same class
bars. Fig 8-58 Removable dies with special notches and grooves to guide reinsertion. These dies. which require a slightly tapered shape. are IV plaster but with a more liquid consistency. Fig 8-65 Frontal view of the finished and squared cast. Fig 8-66 O cclusal view of a sectioned cast
inserted inside the impression to be again subjected to casting. Fig 8-59 Dies reinserted in the cast. The base of the cast has a large trough detailing re. -insertion channels of the removable dies. Fig 8-6.7 Frontal view .of a Geller cast of the case. This type of sectioned cast highlights
to house the terminal projections of the removable dies. Retention grooves have been prepared on the adjoining parts. Fig 8-60 Silicone index the anatomiC charactenst1cs of the g1ng1val margm and prov1des a better VIeW of the dental anatomy and the dentogingival relationship. It is
positioned on the second stone cast. Fig 8-61 Silicone index transferred to the removable-die cast to check positioning. very difficult to create ceramic restorations without having the gingival tissues for reference.
27
CHAPTER 8
.. treatment. Based on this high-quality provisional, • Patient satisfaction

the patient can establish an opinion of the treat • Appearance of the restoration in relation to the
ment before the definitive restoration is completed face and smile
(since a minimum of 10 days is needed before the • Position of the incisal edge relative to the contour
final impressions can be taken) (Figs 8-93 to 8-95). of the lower lip and of the labial commissure
These impressions of the provisional prosthesis in • Emergence of the buccal surfaces of the teeth in
the mouth are used, along with slides of the inter relation to the lip profile
mediate situation, to make only minor changes re • Shape of the prosthetic teeth due to wear or the
lated to shape and soft tissue integration. presence of composite restorations
• Condition of the soft tissues and maturity of the
interdental papillae
In situ eva luation
• Integration of the provisional restoration with
An objective evaluation of the provisional restora adjacent teeth
tion or diagnostic mock-up in situ cannot be con • Occlusion
ducted in a single appointment, since the restora
tion generally proposes a significant change. ••-20 Each parameter should be photographed to give
The preoperative situation frequently results from a the clinician and dental technician the opportunity
slow progressive deterioration of the volume and to assess the overall situation in the laboratory dur
shape of the teeth or the previous restoration. The ing the next phase of the ceramic preparation and
patient is unlikely to immediately adapt to the new determine the corrections, if any, to be made. If sig
B-70
prosthesis because the new restorative parameters nificant changes are required, it may be necessary
differ significantly from the pretreatment situation. to prepare a new provisional prosthesis; the authors
In general, the prosthetic team should avoid adjust· generally prefer to prepare the wax corrections direct-
ing the restoration in the first visit to allow the ly on the provisional prosthesis and then ix the whole
patient the necessary time to grow accustomed to prosthesis in an irreversible hydrocolloid impression.
the provisional restoration. When minor changes are required, the corrections
The provisional prosthesis is evaluated through can be executed di rectly on the definitive ceramic
assessment of the following parameters: work and evaluated during the bisque-bake try-in. •
B-72
Figs 8-68 to 8-75 Provisional stratification. Fig 8-68 Suitably adapted diagnostic waxup. Fig 8-6g Molding phase o f dentin-type acrylic resin
obtained from the silicone matrix. Figs 8-70 and 8-71 Silicone index showing the space available on the labial surfaces as the dentin material
is reduced. Fig 8-72 Silicone index in place after sectioning in the sagittal direction. Fig 8-73 Dentin reduction completed with the incisal edge
significantly reduced.
1 259
CHAPTER 8
.. treatment. Based on this high-quality provisional, • Patient satisfaction

the patient can establish an opinion of the treat • Appearance of the restoration in relation to the
ment before the definitive restoration is completed face and smile
(since a minimum of 10 days is needed before the • Position of the incisal edge relative to the contour
final impressions can be taken) (Figs 8-93 to 8-95). of the lower lip and of the labial commissure
These impressions of the provisional prosthesis in • Emergence of the buccal surfaces of the teeth in
the mouth are used, along with slides of the inter relation to the lip profile
mediate situation, to make only minor changes re • Shape of the prosthetic teeth due to wear or the
lated to shape and soft tissue integration. presence of composite restorations
• Condition of the soft tissues and maturity of the
interdental papillae
In situ eva luation
• Integration of the provisional restoration with
An objective evaluation of the provisional restora adjacent teeth
tion or diagnostic mock-up in situ cannot be con • Occlusion
ducted in a single appointment, since the restora
tion generally proposes a significant change. ••-20 Each parameter should be photographed to give
The preoperative situation frequently results from a the clinician and dental technician the opportunity
slow progressive deterioration of the volume and to assess the overall situation in the laboratory dur
shape of the teeth or the previous restoration. The ing the next phase of the ceramic preparation and
patient is unlikely to immediately adapt to the new determine the corrections, if any, to be made. If sig
B-70
prosthesis because the new restorative parameters nificant changes are required, it may be necessary
differ significantly from the pretreatment situation. to prepare a new provisional prosthesis; the authors
In general, the prosthetic team should avoid adjust· generally prefer to prepare the wax corrections direct-
ing the restoration in the first visit to allow the ly on the provisional prosthesis and then ix the whole
patient the necessary time to grow accustomed to prosthesis in an irreversible hydrocolloid impression.
the provisional restoration. When minor changes are required, the corrections
The provisional prosthesis is evaluated through can be executed di rectly on the definitive ceramic
assessment of the following parameters: work and evaluated during the bisque-bake try-in. •
B-72
Figs 8-68 to 8-75 Provisional stratification. Fig 8-68 Suitably adapted diagnostic waxup. Fig 8-6g Molding phase o f dentin-type acrylic resin
obtained from the silicone matrix. Figs 8-70 and 8-71 Silicone index showing the space available on the labial surfaces as the dentin material
is reduced. Fig 8-72 Silicone index in place after sectioning in the sagittal direction. Fig 8-73 Dentin reduction completed with the incisal edge
significantly reduced.
1 259
CIAPl ER
Fig 8-74 Photopotymerizing colors applied over the dentin layer. Fig 8-75 Molding phase of the enamel-type acrylic resin. Figs 8-76 to 8-78 Lines Fig 8-82 Provisional before insertion in the mouth. The reconstruction of the clinical case involves veneers on the central i n cisors and
c � e ated using contact-detecting powder are useful for defining the shape of the restorations during the finishing phase. Figs 8-7g to 8-81 crowns on the lateral incisors. Fig 8-83 First provisional on 2.1 and 2.2 for whitening . The patient requested improvement i n the shape
. and brilliance of the teeth. Fig 8-84 Provisional in situ. The diagnostic planning done in the laboratory is evaluated direclly i n the mouth with
FiniShed and polished prom1onal restorahons. Note the emergence profiles shown in the lateral views.
the help of the provisional. Fig 8-85 View of the right maxillary incisors showing the anatomy of the restorations. Fig 8-86 View of the left max
illary incisor. Note that the cervical area is no longer gray. as it was i n the previous restorative treatment.
ZG 261
CIAPl ER
Fig 8-74 Photopotymerizing colors applied over the dentin layer. Fig 8-75 Molding phase of the enamel-type acrylic resin. Figs 8-76 to 8-78 Lines Fig 8-82 Provisional before insertion in the mouth. The reconstruction of the clinical case involves veneers on the central i n cisors and
c � e ated using contact-detecting powder are useful for defining the shape of the restorations during the finishing phase. Figs 8-7g to 8-81 crowns on the lateral incisors. Fig 8-83 First provisional on 2.1 and 2.2 for whitening . The patient requested improvement i n the shape
. and brilliance of the teeth. Fig 8-84 Provisional in situ. The diagnostic planning done in the laboratory is evaluated direclly i n the mouth with
FiniShed and polished prom1onal restorahons. Note the emergence profiles shown in the lateral views.
the help of the provisional. Fig 8-85 View of the right maxillary incisors showing the anatomy of the restorations. Fig 8-86 View of the left max
illary incisor. Note that the cervical area is no longer gray. as it was i n the previous restorative treatment.
ZG 261
Fig 8-87 Pre operative view of clinical case. Fig 8-88 Following the diagnostic wax up in the laboratory. distalization of the papilla between the Fig 8- gl Provisional now perfectly adapted to the oral cavity following tissue conditioning. Fig 8- g2 Detail of the provisional after tissue con
_
mmllary _
nght c ! ntral and lateral 1nc1 sors was planned. Fig 8-8g Preparation for tissue conditioning is achieved by removing plaster from ditioning. Fig 8- gJ Cast showing plans for tissue conditioning for a pontic. Fig 8-4 Edentulous site following tissue conditioning. Fig 8-gs Pontic
the Internal g1ng1val port1on """g a sphemal _ in place. perfectly adapted to give the esthetic appearance of a good emergence profile. even though the restoration does not extend sub
bur. resulting in the fabrication of a larger provisional in relation to the existing gingival
g _
tiSsues. Fig 8- o Prom1onal 1n the mouth shows a tiSsue ISChemia corresponding to the area where plaster was removed from the cast. gingivally.
Ul 23
Fig 8-87 Pre operative view of clinical case. Fig 8-88 Following the diagnostic wax up in the laboratory. distalization of the papilla between the Fig 8- gl Provisional now perfectly adapted to the oral cavity following tissue conditioning. Fig 8- g2 Detail of the provisional after tissue con
_
mmllary _
nght c ! ntral and lateral 1nc1 sors was planned. Fig 8-8g Preparation for tissue conditioning is achieved by removing plaster from ditioning. Fig 8- gJ Cast showing plans for tissue conditioning for a pontic. Fig 8-4 Edentulous site following tissue conditioning. Fig 8-gs Pontic
the Internal g1ng1val port1on """g a sphemal _ in place. perfectly adapted to give the esthetic appearance of a good emergence profile. even though the restoration does not extend sub
bur. resulting in the fabrication of a larger provisional in relation to the existing gingival
g _
tiSsues. Fig 8- o Prom1onal 1n the mouth shows a tiSsue ISChemia corresponding to the area where plaster was removed from the cast. gingivally.
Ul 23
CHAPTER 8
REFEREN CES 7. Brisman S. Esthetics: A comparison of dentists' and 13. Albergo G, Sampalmieri F, Mattioli Belmonte M, 18. Youdelis RA, Faucher R. Provisional restorations: An
patients' concepts. J Am Dent Assoc t98o:too:345-352. Andreana S. echanical performance of some dental integrated approach to periodontics and restorative
1. Levinson NLA. Psychologic acets of esthetic dental 8. Albino JE. Tedesco LA. Conny DJ. Patient perceptions of acrylic resin. J Dent Res t997:76:11o3. dentistry. Dent Clin North Am t98o:24:285-303.
care: A developmental perspective. J Prosthet Dent dental-facial esthetics: Shared concerns in orthodontics 14. Liu Cl. Use of a modiied ovate pontic in areas of ridge 19. Moulding MB, Loney RW. The efect of cooling tech
1990:64:486-491. and prosthodontics. J Prosthet Dent 1984:5 2:9-13. defects: A repon of two cases. J Esthet Restor Dent niques on intrapulpal temperature during direct abrica
2. Ellmann ). Compression formed plaster shells for tem 9- Romeo G. II prowisorio diagnostico per comprendere it 2004;16:273-2Bt: discussion 282-283. tion of provisional restorations. lnt I Prosthodont 1991;
porary splints. Dent Dig 1971:77:334-339· concetto del trattamento estetico. Dent Dialogue 15. Miller MB. Ovate pontics: The natural tooth replacement. 4:33 2-336.
3- Krug RS. Multiple use of plastic template in fixed 200t;5:44o-453· Pract Periodontics Aesthet Dent 1996:8:140. 20. Dubois R). Kyriakakis P, Weiner S, Vaidyanathan TK.
prosthodontics. J Prosthet Dent 1973:30:745-748. 10. isher D, Shillingburg HT Jr. Dewhirst RB. Indirect tem 16. Emtiaz S, Tarnow DP. Processed acrylic resin provision Efects of occlusal loading and thermocycling on the
4- Preston JD. A systematic approach to the control of porary restorations. J Am Dent Assoc 1971;82: 16o-t63. al restoration with lingual cast metal ramewor.. J marginal gaps of light-polymerized and autopolymer·
esthetic form. J Prosthet Dent 1976:35 :393-402. 11. Albergo G. Accarisi E. Sampalmieri F, Bedini R. Andreana Prosthet Dent 1998:79:484-488. ized resin provisional crowns. I Prosthet Dent 1999;
s. Cho GC, Donovan TE. Chee NL. Clinical experiences 5. Efect of antimicrobical ingredients on mechanical 17. Ogawa T, Ai2awa S, Tanaka M, atsuya S, Hasegawa A. 82: 16!-!66.
with bonded porcelain laminate veneers. J Cal Dent performance in acrylic resin (abstract 2128). J Dent Res Koyano K. Efect of water temperature on the it of pro
Assoc 1998:26:t21-127. 1997:76(special issue):279· visional crown margins during polymerization. I
6. Donovan TE, Cho GC. Diagnostic provisional restora· 12. Capelli M, Albergo G, Casolari L, Sampalmieri F, Bedini Prosthet Dent 1999:B2:6sH61.
tions in restorative dentistry: The blueprint for success. R. Antibacterial activity of a resin: A qualitative study. J
J Can Dent Assoc 1999:65:272-275- Dent Res 1998:77:1389.
25
CHAPTER 8
REFEREN CES 7. Brisman S. Esthetics: A comparison of dentists' and 13. Albergo G, Sampalmieri F, Mattioli Belmonte M, 18. Youdelis RA, Faucher R. Provisional restorations: An
patients' concepts. J Am Dent Assoc t98o:too:345-352. Andreana S. echanical performance of some dental integrated approach to periodontics and restorative
1. Levinson NLA. Psychologic acets of esthetic dental 8. Albino JE. Tedesco LA. Conny DJ. Patient perceptions of acrylic resin. J Dent Res t997:76:11o3. dentistry. Dent Clin North Am t98o:24:285-303.
care: A developmental perspective. J Prosthet Dent dental-facial esthetics: Shared concerns in orthodontics 14. Liu Cl. Use of a modiied ovate pontic in areas of ridge 19. Moulding MB, Loney RW. The efect of cooling tech
1990:64:486-491. and prosthodontics. J Prosthet Dent 1984:5 2:9-13. defects: A repon of two cases. J Esthet Restor Dent niques on intrapulpal temperature during direct abrica
2. Ellmann ). Compression formed plaster shells for tem 9- Romeo G. II prowisorio diagnostico per comprendere it 2004;16:273-2Bt: discussion 282-283. tion of provisional restorations. lnt I Prosthodont 1991;
porary splints. Dent Dig 1971:77:334-339· concetto del trattamento estetico. Dent Dialogue 15. Miller MB. Ovate pontics: The natural tooth replacement. 4:33 2-336.
3- Krug RS. Multiple use of plastic template in fixed 200t;5:44o-453· Pract Periodontics Aesthet Dent 1996:8:140. 20. Dubois R). Kyriakakis P, Weiner S, Vaidyanathan TK.
prosthodontics. J Prosthet Dent 1973:30:745-748. 10. isher D, Shillingburg HT Jr. Dewhirst RB. Indirect tem 16. Emtiaz S, Tarnow DP. Processed acrylic resin provision Efects of occlusal loading and thermocycling on the
4- Preston JD. A systematic approach to the control of porary restorations. J Am Dent Assoc 1971;82: 16o-t63. al restoration with lingual cast metal ramewor.. J marginal gaps of light-polymerized and autopolymer·
esthetic form. J Prosthet Dent 1976:35 :393-402. 11. Albergo G. Accarisi E. Sampalmieri F, Bedini R. Andreana Prosthet Dent 1998:79:484-488. ized resin provisional crowns. I Prosthet Dent 1999;
s. Cho GC, Donovan TE. Chee NL. Clinical experiences 5. Efect of antimicrobical ingredients on mechanical 17. Ogawa T, Ai2awa S, Tanaka M, atsuya S, Hasegawa A. 82: 16!-!66.
with bonded porcelain laminate veneers. J Cal Dent performance in acrylic resin (abstract 2128). J Dent Res Koyano K. Efect of water temperature on the it of pro
Assoc 1998:26:t21-127. 1997:76(special issue):279· visional crown margins during polymerization. I
6. Donovan TE, Cho GC. Diagnostic provisional restora· 12. Capelli M, Albergo G, Casolari L, Sampalmieri F, Bedini Prosthet Dent 1999:B2:6sH61.
tions in restorative dentistry: The blueprint for success. R. Antibacterial activity of a resin: A qualitative study. J
J Can Dent Assoc 1999:65:272-275- Dent Res 1998:77:1389.
25
C H A P T E R 9
C U S T O M IM P RESS I O N TRAY S
A N D IM P RESS I O N MATER IAL S
FIG 9-1 FIG 9-2
I
n dental prosthetics, the impression is essential sizes to accommodate almost every clinical situa
for fabricating a restoration. If the proper proce tion, eg, polystyrene, plastic, aluminum, or steel;
dures are not followed, the clinician may intro perforated or nonperforated; etc (Figs 9-1 to 9-3).
duce errors or distortions that cannot be eliminated During setting, the chemical reaction of the paste
or corrected in subsequent stages. The impression and catalyst can lead to shrinkage, which alters the
communicates the clinical condition of the patient's shape and dimension and compromises the preci
mouth to the dental technician; therefore, an sion of the impression. To minimize shrinkage, the
impression that faithfully records the details of a thickness of impression material should be ade
dental arch leads to a well-adapted restoration. A quate to accurately record every stressed clinical sit
precise impression can be made using several dif uation (natural undercuts, convex, natural tooth),
FIG 9-3
ferent types of materials and impression trays. The but no thickerJ·•
clinician must understand the techniques and fac
tors that ensure an accurate impression. The follow
Custom i m p ression trays
ing general overview details the procedures typical
ly used by the authors. Clinicians can regulate the thickness of an impres
sion by making custom impression trays out of
photopolymerizable resin. By molding a 3-mm-thick
I M PRES S I O N TRAYS
sheet of soft wax around the dental arch on a diag
An impression material generally consists of a paste nostic cast before molding the resin, the clinician
and a catalyst that gradually harden when mixed can create the ideal thickness for the impression
together. Once the paste and catalyst come in con material (Fig 9-4). Some authorsS-6 do not agree that
tact, the impression material begins to increase in custom trays are necessary for precise impressions,
viscosity and slowly develops elasticity. This gradual believing that the degree of shrinkage of impression
hardening permits the clinician to position the mate materials is clinically insignificant. However, custom FIG 9-4 FIG 9-5
rial while it is still in an plastic state (working stage) trays can mitigate another important phenomenon
before it hardens into a elastic state. '·2 distortion caused by undercuts.
Figs g-1 to g -3 Stock trays. Fig g -1 Polystyrene tray. These trays are very flexible and are unsuitable for precision impressions. ' However. they
While it is in a plastic state, the impression mate In the authors' opinion, one of the greatest can be used to make a full plaster impression of implants because they can be cut easily afler casting. Fig g -2 Perforated aluminum tray.
rial is placed in a suitable tray for the arch being stresses on impression materials is the presence of Perforated trays. including those in steel. are unsuitable for impression taking because the perforations can create anomalies in the impres
sion.1 Fig g-3 Solid steel tray. These trays must be boxed in with wax to ensure good adaptation. Fig g _4 Sheet of spacing wax that is molded
impressed. Manufacturers fabricate impression trays undercuts, for example, found in the natural anato direclly on top of the diagnostic cast. Its thickness !generally 3 mml creates the ideal space for the impression material. Fig g_s Tooth prepa
ration for a complete crown. The horizontal retraction creates a pronounced undercut formed by the natural taper of the root.
out of different materials and in various shapes and my of intact maxillary teeth. Apical to the initial pro- ..
zu 217
C H A P T E R 9
C U S T O M IM P RESS I O N TRAY S
A N D IM P RESS I O N MATER IAL S
FIG 9-1 FIG 9-2
I
n dental prosthetics, the impression is essential sizes to accommodate almost every clinical situa
for fabricating a restoration. If the proper proce tion, eg, polystyrene, plastic, aluminum, or steel;
dures are not followed, the clinician may intro perforated or nonperforated; etc (Figs 9-1 to 9-3).
duce errors or distortions that cannot be eliminated During setting, the chemical reaction of the paste
or corrected in subsequent stages. The impression and catalyst can lead to shrinkage, which alters the
communicates the clinical condition of the patient's shape and dimension and compromises the preci
mouth to the dental technician; therefore, an sion of the impression. To minimize shrinkage, the
impression that faithfully records the details of a thickness of impression material should be ade
dental arch leads to a well-adapted restoration. A quate to accurately record every stressed clinical sit
precise impression can be made using several dif uation (natural undercuts, convex, natural tooth),
FIG 9-3
ferent types of materials and impression trays. The but no thickerJ·•
clinician must understand the techniques and fac
tors that ensure an accurate impression. The follow
Custom i m p ression trays
ing general overview details the procedures typical
ly used by the authors. Clinicians can regulate the thickness of an impres
sion by making custom impression trays out of
photopolymerizable resin. By molding a 3-mm-thick
I M PRES S I O N TRAYS
sheet of soft wax around the dental arch on a diag
An impression material generally consists of a paste nostic cast before molding the resin, the clinician
and a catalyst that gradually harden when mixed can create the ideal thickness for the impression
together. Once the paste and catalyst come in con material (Fig 9-4). Some authorsS-6 do not agree that
tact, the impression material begins to increase in custom trays are necessary for precise impressions,
viscosity and slowly develops elasticity. This gradual believing that the degree of shrinkage of impression
hardening permits the clinician to position the mate materials is clinically insignificant. However, custom FIG 9-4 FIG 9-5
rial while it is still in an plastic state (working stage) trays can mitigate another important phenomenon
before it hardens into a elastic state. '·2 distortion caused by undercuts.
Figs g-1 to g -3 Stock trays. Fig g -1 Polystyrene tray. These trays are very flexible and are unsuitable for precision impressions. ' However. they
While it is in a plastic state, the impression mate In the authors' opinion, one of the greatest can be used to make a full plaster impression of implants because they can be cut easily afler casting. Fig g -2 Perforated aluminum tray.
rial is placed in a suitable tray for the arch being stresses on impression materials is the presence of Perforated trays. including those in steel. are unsuitable for impression taking because the perforations can create anomalies in the impres
sion.1 Fig g-3 Solid steel tray. These trays must be boxed in with wax to ensure good adaptation. Fig g _4 Sheet of spacing wax that is molded
impressed. Manufacturers fabricate impression trays undercuts, for example, found in the natural anato direclly on top of the diagnostic cast. Its thickness !generally 3 mml creates the ideal space for the impression material. Fig g_s Tooth prepa
ration for a complete crown. The horizontal retraction creates a pronounced undercut formed by the natural taper of the root.
out of different materials and in various shapes and my of intact maxillary teeth. Apical to the initial pro- ..
zu 217
CHAPTER 9
Custom I mpression Trays and Impression Materials
.. trusion of the tooth in the area of the dental alve around the vestibular fornix to delimit the edge of
oli, there is a depression of varying extent in the the tray (Figs 9-8 to 9-10). Occlusal stops are made
area of the vestibular fornix; clinical treatment to by creating small depressions, with adequate exten
modify the shape and length of the clinical crown sions, in the anterior hard palate and edentulous
can reveal natural undercuts (Fig 9-5). Undercuts can areas. A sufficient number of well-positioned stops
also be erroneously created during tooth prepara are needed to provide tripod-like stability; if there FIG 9-6 FIG 9-7
tion, a risk that is often underestimated as a poten are no edentulous areas, additional stops can be
tial cause of the impression distotion that leads to made against the palatal mucosa at the level of the
poor adaptation of the restoration. The clinician maxillary first molars. If this is not possible for ana
must be aware of all undercuts while preparing the tomic reasons (eg, a lack of edentulous areas in the
custom tray and block out those areas with addi mandible or the presence of an accentuated palate),
tional spacing wax. By leaving more room in the cus the cusps of teeth in noncritical areas {ie, those not
tom tray for a thicker application of material to the afecting functional movements, such as the buccal
undercuts, the impression should be able to with cusps of maxillay teeth and the lingual cusps of man
stand the force required to remove it from the oral dibular teeth) can be used as support for the tripod.
cavity without laceration or stretching. For these rea Light-curing resin (MultiTray, 3M ESPE) is used to
sons, the clinician should use custom trays to obtain make the tray. The stops and detachment wings are
a suitable impression.' prepared first by placing small amounts of resin in FIG 9-8 FIG 9-9
the wax depressions that are then polymerized for 5
Fabrication of the custom i m p ression tray to 10 seconds in a light-curing unit (Multilight, 3M
To make a custom impression tray, stat by evaluat ESPE) (Fig 9-11) so they will adhere to the rest of the
ing the stone cast, which will be marked according resin.
to the planned form and dimension of the custom The main sheet of resin is applied over the wax
tray and to prevent material from locking into the and the prepolymerized stops and carefully adapted
marked undercuts. Using a graphite pencil or wax to the design of the tray. Once the central handle
crayon, the clinician traces the limits of the tray's and the detachment wings are shaped, the custom
apical extension taking care to avoid the involve made tray, prepared on the plaster model, is placed
ment of the vestibular fornix and to include the area i n the light-curing unit for 5 minutes (Figs 9-12 to
2 m m apical to the inish line (Figs 9-6 and 9-7). 9-14). The tray undergoes two polymerizations of s
To obtain ideal thickness. a 3-mm wax sheet is minutes each, first for the exterior and then for the
FIG 9-10 FIG 9-11
heated to 40°C and then molded to the diagnostic interior, without removing the spacing wax. The spac
cast, following the guide marks. Additional wax is ing wax is finally removed, and the tray is placed in
adapted to areas of pronounced natural undercuts so the light-polymerizing unit for another 5 minutes to
that the tray will withstand the extra stress in these cure the interior surface (Fig 9-15).
areas. Thus, the custom impression tray will not be Once the polymerization is finished, the tray must
Fi gs 9-6 and 9-7 Graphite pencil or a wax crayon is used to mark the placement of occlusal slops and the borders of the custom lny that extend
of uniform thickness but of controlled thickness. be evaluated on the cast to ensure that the stops 2 mm apical to the finish line. However. in areas of the mouth thai are not involved in the restoration. the impression should not exlend beyond
the finish line to minimize the number of natural undercuts in the impression. Fig 9-8 and 9-9 A laboratory scalpel is used to cut the spacing
Once the wax sheet has been adapted to the make proper contact with the desired areas (Figs wax at the tray limits marked in graphite and in the areas for occlusal stops. Fig g -10 Cut-out areas are filled in with pieces of light-curing
plaster cast, the clinician uses a laboratory knife to 9-16 and 9-17) and the detachment wings and the resin to ereale lhe occlusal stops for sealing lhe impression. Fig 9-ll lighl-curing unit. The occlusal stops are polymerized for a few sec
onds so that the partially hardened resin will adhere to the main sheet of resin.
trim excess wax from the cast according to plan and han dle are correctly positioned (Fig 9-18). Using t u n g- �
21 2"
CHAPTER 9
.. trusion of the tooth in the area of the dental alve around the vestibular fornix to delimit the edge of
oli, there is a depression of varying extent in the the tray (Figs 9-8 to 9-10). Occlusal stops are made
area of the vestibular fornix; clinical treatment to by creating small depressions, with adequate exten
modify the shape and length of the clinical crown sions, in the anterior hard palate and edentulous
can reveal natural undercuts (Fig 9-5). Undercuts can areas. A sufficient number of well-positioned stops
also be erroneously created during tooth prepara are needed to provide tripod-like stability; if there FIG 9-6 FIG 9-7
tion, a risk that is often underestimated as a poten are no edentulous areas, additional stops can be
tial cause of the impression distotion that leads to made against the palatal mucosa at the level of the
poor adaptation of the restoration. The clinician maxillary first molars. If this is not possible for ana
must be aware of all undercuts while preparing the tomic reasons (eg, a lack of edentulous areas in the
custom tray and block out those areas with addi mandible or the presence of an accentuated palate),
tional spacing wax. By leaving more room in the cus the cusps of teeth in noncritical areas {ie, those not
tom tray for a thicker application of material to the afecting functional movements, such as the buccal
undercuts, the impression should be able to with cusps of maxillay teeth and the lingual cusps of man
stand the force required to remove it from the oral dibular teeth) can be used as support for the tripod.
cavity without laceration or stretching. For these rea Light-curing resin (MultiTray, 3M ESPE) is used to
sons, the clinician should use custom trays to obtain make the tray. The stops and detachment wings are
a suitable impression.' prepared first by placing small amounts of resin in FIG 9-8 FIG 9-9
the wax depressions that are then polymerized for 5
Fabrication of the custom i m p ression tray to 10 seconds in a light-curing unit (Multilight, 3M
To make a custom impression tray, stat by evaluat ESPE) (Fig 9-11) so they will adhere to the rest of the
ing the stone cast, which will be marked according resin.
to the planned form and dimension of the custom The main sheet of resin is applied over the wax
tray and to prevent material from locking into the and the prepolymerized stops and carefully adapted
marked undercuts. Using a graphite pencil or wax to the design of the tray. Once the central handle
crayon, the clinician traces the limits of the tray's and the detachment wings are shaped, the custom
apical extension taking care to avoid the involve made tray, prepared on the plaster model, is placed
ment of the vestibular fornix and to include the area i n the light-curing unit for 5 minutes (Figs 9-12 to
2 m m apical to the inish line (Figs 9-6 and 9-7). 9-14). The tray undergoes two polymerizations of s
To obtain ideal thickness. a 3-mm wax sheet is minutes each, first for the exterior and then for the
FIG 9-10 FIG 9-11
heated to 40°C and then molded to the diagnostic interior, without removing the spacing wax. The spac
cast, following the guide marks. Additional wax is ing wax is finally removed, and the tray is placed in
adapted to areas of pronounced natural undercuts so the light-polymerizing unit for another 5 minutes to
that the tray will withstand the extra stress in these cure the interior surface (Fig 9-15).
areas. Thus, the custom impression tray will not be Once the polymerization is finished, the tray must
Fi gs 9-6 and 9-7 Graphite pencil or a wax crayon is used to mark the placement of occlusal slops and the borders of the custom lny that extend
of uniform thickness but of controlled thickness. be evaluated on the cast to ensure that the stops 2 mm apical to the finish line. However. in areas of the mouth thai are not involved in the restoration. the impression should not exlend beyond
the finish line to minimize the number of natural undercuts in the impression. Fig 9-8 and 9-9 A laboratory scalpel is used to cut the spacing
Once the wax sheet has been adapted to the make proper contact with the desired areas (Figs wax at the tray limits marked in graphite and in the areas for occlusal stops. Fig g -10 Cut-out areas are filled in with pieces of light-curing
plaster cast, the clinician uses a laboratory knife to 9-16 and 9-17) and the detachment wings and the resin to ereale lhe occlusal stops for sealing lhe impression. Fig 9-ll lighl-curing unit. The occlusal stops are polymerized for a few sec
onds so that the partially hardened resin will adhere to the main sheet of resin.
trim excess wax from the cast according to plan and han dle are correctly positioned (Fig 9-18). Using t u n g- �
21 2"
HI
Custom Impression Trays and Impression Materials
. sten carbide burs with a crossover cut (no. H77 EF, When necessary (eg, in cases with pronounced under
H79 EF, H351 EF; Komet), the rough tray is finished cuts), a wax net designed to make metallic supports
by removing the excess material and smoothing the for prosthetic frames can be placed over the wax
sharp edges and irregularities. The internal surface foundation to enhance microretention (Figs 9-20 to
of the tray is carefully washed with a grease-cutting 9-22). When pressed onto the sheet of spacing wax,
product (eg, rectified benzine) to remove the oily this wax-net layer creates small raised bumps that
residue left by the wax. will be transferred to the interior surface of the tray
Elastomer adhesion is a constant problem in im (Fig 9-23).
pression taking because impression materials with The tray must be tested in the patient's mouth.
strong internal cohesion, such as addition silicones At least 30 minutes before the impression is taken,
and polyethers, do not adhere well to the resin sur an adhesive that is compatible with the impression
face of the tray.8 To improve the adhesion when material must be applied to the tray. A minimum of
using polyethers. a groove can be made with a 15 minutes is needed to ensure that the adhesive is
small-diameter tungsten carbide bur on the interior completely dry9; if it is wet, the adhesive will insu
surface directly below the edge of the tray (Fig 9-19). late rather than bond (Fig 9-24). ..
rest on the soft tissue. It is preferable to establish occlusal stops on the mucous areas of the palate or tn edentulous Sites. rather than on
the surface of teeth. Fig g. 18 Internal surface of the custom tray after cleaning with rectified benz1nt and finishing the margins and borders.
fig g-19 Mechanical retention groove for the impression material. Fig 9-20 Sheet of wax netting normally used in fabricallon of metallic frames
for removable partial prostheses. Figs 9-21 and g-22 The wax net pattern increases microretenlion between elastomer tmpression materials and
Ftgs g.12 and g.13 Moldtng of the sheet of restn dtroctly on the spacing wax and the partially polymerized stops. Ftg g-14 After the resin material of the custom tray Elastomers have high cohesion and therefore adhere poorly to many surfaces Ftg g.23 High-magntftealion
lha handle and detachment wings are made. the top and bottom surfaces of the tray are polymerized for 5 minutes each with shows the close mechanical adaptation between an elastomer impresSion material and the reSin of the custom tray The liquid adhesive layer
out removtng lhe spacing wax . Ftg 9-15 After removal of the spacing wax. the interior surface of the hardened impression tray between the elastomer and resin increases adhesion Fig g-24 Polyelher-compallble adhesive The adhesive is applied with a brush to the
is cured for an addthonal 5 mtnulu Figs 9·16 and 9-17 Fintshad custom tray Sealed on tho cast. the principal occlusal stops internal surface of the custom tray to facilitate adheSion of the impression matenal lo the light-curing resin
211
HI
. sten carbide burs with a crossover cut (no. H77 EF, When necessary (eg, in cases with pronounced under
H79 EF, H351 EF; Komet), the rough tray is finished cuts), a wax net designed to make metallic supports
by removing the excess material and smoothing the for prosthetic frames can be placed over the wax
sharp edges and irregularities. The internal surface foundation to enhance microretention (Figs 9-20 to
of the tray is carefully washed with a grease-cutting 9-22). When pressed onto the sheet of spacing wax,
product (eg, rectified benzine) to remove the oily this wax-net layer creates small raised bumps that
residue left by the wax. will be transferred to the interior surface of the tray
Elastomer adhesion is a constant problem in im (Fig 9-23).
pression taking because impression materials with The tray must be tested in the patient's mouth.
strong internal cohesion, such as addition silicones At least 30 minutes before the impression is taken,
and polyethers, do not adhere well to the resin sur an adhesive that is compatible with the impression
face of the tray.8 To improve the adhesion when material must be applied to the tray. A minimum of
using polyethers. a groove can be made with a 15 minutes is needed to ensure that the adhesive is
small-diameter tungsten carbide bur on the interior completely dry9; if it is wet, the adhesive will insu
surface directly below the edge of the tray (Fig 9-19). late rather than bond (Fig 9-24). ..
rest on the soft tissue. It is preferable to establish occlusal stops on the mucous areas of the palate or tn edentulous Sites. rather than on
the surface of teeth. Fig g. 18 Internal surface of the custom tray after cleaning with rectified benz1nt and finishing the margins and borders.
fig g-19 Mechanical retention groove for the impression material. Fig 9-20 Sheet of wax netting normally used in fabricallon of metallic frames
for removable partial prostheses. Figs 9-21 and g-22 The wax net pattern increases microretenlion between elastomer tmpression materials and
Ftgs g.12 and g.13 Moldtng of the sheet of restn dtroctly on the spacing wax and the partially polymerized stops. Ftg g-14 After the resin material of the custom tray Elastomers have high cohesion and therefore adhere poorly to many surfaces Ftg g.23 High-magntftealion
lha handle and detachment wings are made. the top and bottom surfaces of the tray are polymerized for 5 minutes each with shows the close mechanical adaptation between an elastomer impresSion material and the reSin of the custom tray The liquid adhesive layer
out removtng lhe spacing wax . Ftg 9-15 After removal of the spacing wax. the interior surface of the hardened impression tray between the elastomer and resin increases adhesion Fig g-24 Polyelher-compallble adhesive The adhesive is applied with a brush to the
is cured for an addthonal 5 mtnulu Figs 9·16 and 9-17 Fintshad custom tray Sealed on tho cast. the principal occlusal stops internal surface of the custom tray to facilitate adheSion of the impression matenal lo the light-curing resin
211
CHAPTER 9
• CHARACTER I STICS OF I M PRESSION does not alter their precision or accurate reproduc • Flu i d ity and viscosity polyvinyl siloxanes and polyesters have greater co·
M ATER IALS FOR FIXED tion of the details. Many authors have recognized hesion than adhesion (ie, poor wetting), while hydro
RESTORATI O N S the need to disi nfect impressions as a precaution to Fluidity measures a material's capacity to insinuate colloids have greater adhesion than cohesion (ie,
remove any pathogens that may have been present itself into the minute spaces of an object and there good wetting). This means that when polyvinyl silox
i n the oral cavity.•6·'' A number of scientific studies by faithfully reproduce its smallest details. Fluidity is anes and polyesters are used, the clinician should
The impression communicates all the parameters have been performed to evaluate the effect of vari a characteristic found primarily in detail materials, add an adhesive to ensure that the material will
and details needed by the dental technician to cor ous disinfectants on impression materials. In a sur which are generally used directly in the dentogingi adhere to the impression tray. Most manufacturers
rectly execute a fixed restoration. In practical terms, vey of im pression disinfection in 400 US dental lab val sulcus to reproduce the finish line and the intact add substances to impression materials to reduce
the impression is a negative or inverse form of the oratories, Kugel et al'8 found that only 44% of tooth structure beyond. Conversely, support materi surface tension. Wettability is affected by disinfec
prepared tooth. The impression must be a faithful impressions were disinfected directly by clinicians. als are classified according to their viscosity (high, tion 2 1·30-3' but the effed is not clinically significant.
reproduction of the preparation and clinical situa Of these, the modality was undocumented in 23% medium, and low) and function to suppot and
tion, free from alterations, which are often imper and the time of immersion was undocumented in guide the low-viscosity detail materials. The viscos
Elastic me mory
ceptible and frequently caused by distortion of the 47°/o. The effects of the various disinfectant modali ity of support materials is determined by placing 0.5
i mpression materials'0 (Figs 9-25 and 9-26). ties on different impression materials are well docu ml of the material on two flat plates (ISO 4823). Ten Elastic memory refers to a material's capacity to
Some clinicians and dental technicians subscribe mented.'9-2S Following disinfection, in solutions con seconds after extrusion, the plates are subjected to recover its original shape after it has been
to the belief that impression materials are distotion taining 2% glutaraldehyde (glyoxal glutaraldehyde, 1.5 N for 30 seconds. High- and very high-viscosity deformed. The greater the degree of deformity, the
proof. The literature is illed with in vitro studies"-'3 phenol glutaraldehyde) or 5 - 25°/o sodium hypochlo materials yield a diameter of less than 35 mm, more time that should pass before pouring the
demonstrating that polyethers and especially poly rite for periods ranging from 10 to 30 minutes,26 for medium-viscosity materials yield a diameter of 31 to stone impression. There is no codified system to
vinyl siloxanes are stable, provide accurate surface example, impression materials generally maintain 41 mm, and low-viscosity materials yield a diameter define the degree and type of impression deforma
details, and resist deformation. Without disputing their clinical acceptability and the precision of the of more than 36 mm. tion or the period of time to wait for the material to
their validity, the authors believe such studies do impression. However, Johnson et al27 evaluated the Viscosity correlates with accuracy, resistance to recover its original shape before pouring a stone
not take into account the diferent situations that dimensions of various materials after disinfection deformation, dimensional stability, and tear resis cast. However, for materials that have a suitable
arise in clinical practice. In vivo, the elasticity limit and found that irreversible hydrocolloids expanded tance but is unfavorable for detail precision and dimensional stability, manuadurers have empha
of impression materials is often exceeded,' thus 1.4 to 1.7 �m buccolingually, polyvinyl siloxanes ex ease of handling.8 Hardness, commonly expressed in sized precise minimum and maximum time periods
compromising the original dimensions. panded 6 to 8 �m. and polyethers expanded 11 to shore units, varies over time, increasing after 15 that must elapse before a cast is poured.'
16 �m. minutes, 1 hour, and 24 hours (see the section on Elastic memory is inversely related to permanent
For purposes of clinical evaluation, impression ma polyethers later in this chapter). This property influ deformation: that is, a material with minimal elastic
Detail reproduction and disi nfection
terials are classified as either elastic or nonelastic.'8 ences dimensional stability. memoy will produce an impression with a signifi
The American Dental Association (ADA) defines a Elastic materials include reversible hydrocolloid (agar); cant capacity for permanent deformation. To devel
material as precise when it can reproduce the form i rreversible hydrocolloid (alginate); and synthetics op completely, elastic memory of an i mpression
Wetta bility
of a 20-�m triangular sulcus (method for the preci such as polysulfide, condensation silicone, polyvinyl material requires a length of time that is in dired
sion verification according to DIN 13913)-4 (Figs 9-27 siloxanes, and polyether. Nonelastic materials include Wettability, or low surface tension, describes how a proportion to the size of the undercuts (Fig 9-30).
and 9-28). Elastomers are generally able to repro plaster, thermoplastic pastes, zinc oxide-eugenol material adapts to a contact surface. Wettability is The elastic limit of elastomers is easily exceeded;
duce details the size of a few microns, and exact pastes, and waxes. The requisite characteristics8 of determined by the contact angle formed (theta) even minimal tension or stress to the material while
reproduction of details requires a material to repro an impression material can be evaluated on the when a given quantity of paste is positioned on a taking the impression (eg, using force to remove the
duce features as small as 2 �m. and in some cases, basis of fluidity and viscosity, wettability, elastic surface with a film of water: the smaller the angle of impression from undercuts) will prevent the materi
even under 1 �m.•s memory, thixotropy, dimensional stability, tear contact, the better the material will adapt to the sur al from returning to its original shape and condition.
To prevent the transmission of infection, impres strength, hydrophilic behavior, thermal expansion, ace to be impressed (Fig 9-29). The balance between The ADA sets 2.5% as the limit of acceptability for
sions must be disinfected using a treatment that and application range. . cohesion and adhesion is an impotant factor i n permanent deformation'4 (Fig 9-31). .
determining a material's wettability. For example,
2 3
CHAPTER 9
• CHARACTER I STICS OF I M PRESSION does not alter their precision or accurate reproduc • Flu i d ity and viscosity polyvinyl siloxanes and polyesters have greater co·
M ATER IALS FOR FIXED tion of the details. Many authors have recognized hesion than adhesion (ie, poor wetting), while hydro
RESTORATI O N S the need to disi nfect impressions as a precaution to Fluidity measures a material's capacity to insinuate colloids have greater adhesion than cohesion (ie,
remove any pathogens that may have been present itself into the minute spaces of an object and there good wetting). This means that when polyvinyl silox
i n the oral cavity.•6·'' A number of scientific studies by faithfully reproduce its smallest details. Fluidity is anes and polyesters are used, the clinician should
The impression communicates all the parameters have been performed to evaluate the effect of vari a characteristic found primarily in detail materials, add an adhesive to ensure that the material will
and details needed by the dental technician to cor ous disinfectants on impression materials. In a sur which are generally used directly in the dentogingi adhere to the impression tray. Most manufacturers
rectly execute a fixed restoration. In practical terms, vey of im pression disinfection in 400 US dental lab val sulcus to reproduce the finish line and the intact add substances to impression materials to reduce
the impression is a negative or inverse form of the oratories, Kugel et al'8 found that only 44% of tooth structure beyond. Conversely, support materi surface tension. Wettability is affected by disinfec
prepared tooth. The impression must be a faithful impressions were disinfected directly by clinicians. als are classified according to their viscosity (high, tion 2 1·30-3' but the effed is not clinically significant.
reproduction of the preparation and clinical situa Of these, the modality was undocumented in 23% medium, and low) and function to suppot and
tion, free from alterations, which are often imper and the time of immersion was undocumented in guide the low-viscosity detail materials. The viscos
Elastic me mory
ceptible and frequently caused by distortion of the 47°/o. The effects of the various disinfectant modali ity of support materials is determined by placing 0.5
i mpression materials'0 (Figs 9-25 and 9-26). ties on different impression materials are well docu ml of the material on two flat plates (ISO 4823). Ten Elastic memory refers to a material's capacity to
Some clinicians and dental technicians subscribe mented.'9-2S Following disinfection, in solutions con seconds after extrusion, the plates are subjected to recover its original shape after it has been
to the belief that impression materials are distotion taining 2% glutaraldehyde (glyoxal glutaraldehyde, 1.5 N for 30 seconds. High- and very high-viscosity deformed. The greater the degree of deformity, the
proof. The literature is illed with in vitro studies"-'3 phenol glutaraldehyde) or 5 - 25°/o sodium hypochlo materials yield a diameter of less than 35 mm, more time that should pass before pouring the
demonstrating that polyethers and especially poly rite for periods ranging from 10 to 30 minutes,26 for medium-viscosity materials yield a diameter of 31 to stone impression. There is no codified system to
vinyl siloxanes are stable, provide accurate surface example, impression materials generally maintain 41 mm, and low-viscosity materials yield a diameter define the degree and type of impression deforma
details, and resist deformation. Without disputing their clinical acceptability and the precision of the of more than 36 mm. tion or the period of time to wait for the material to
their validity, the authors believe such studies do impression. However, Johnson et al27 evaluated the Viscosity correlates with accuracy, resistance to recover its original shape before pouring a stone
not take into account the diferent situations that dimensions of various materials after disinfection deformation, dimensional stability, and tear resis cast. However, for materials that have a suitable
arise in clinical practice. In vivo, the elasticity limit and found that irreversible hydrocolloids expanded tance but is unfavorable for detail precision and dimensional stability, manuadurers have empha
of impression materials is often exceeded,' thus 1.4 to 1.7 �m buccolingually, polyvinyl siloxanes ex ease of handling.8 Hardness, commonly expressed in sized precise minimum and maximum time periods
compromising the original dimensions. panded 6 to 8 �m. and polyethers expanded 11 to shore units, varies over time, increasing after 15 that must elapse before a cast is poured.'
16 �m. minutes, 1 hour, and 24 hours (see the section on Elastic memory is inversely related to permanent
For purposes of clinical evaluation, impression ma polyethers later in this chapter). This property influ deformation: that is, a material with minimal elastic
Detail reproduction and disi nfection
terials are classified as either elastic or nonelastic.'8 ences dimensional stability. memoy will produce an impression with a signifi
The American Dental Association (ADA) defines a Elastic materials include reversible hydrocolloid (agar); cant capacity for permanent deformation. To devel
material as precise when it can reproduce the form i rreversible hydrocolloid (alginate); and synthetics op completely, elastic memory of an i mpression
Wetta bility
of a 20-�m triangular sulcus (method for the preci such as polysulfide, condensation silicone, polyvinyl material requires a length of time that is in dired
sion verification according to DIN 13913)-4 (Figs 9-27 siloxanes, and polyether. Nonelastic materials include Wettability, or low surface tension, describes how a proportion to the size of the undercuts (Fig 9-30).
and 9-28). Elastomers are generally able to repro plaster, thermoplastic pastes, zinc oxide-eugenol material adapts to a contact surface. Wettability is The elastic limit of elastomers is easily exceeded;
duce details the size of a few microns, and exact pastes, and waxes. The requisite characteristics8 of determined by the contact angle formed (theta) even minimal tension or stress to the material while
reproduction of details requires a material to repro an impression material can be evaluated on the when a given quantity of paste is positioned on a taking the impression (eg, using force to remove the
duce features as small as 2 �m. and in some cases, basis of fluidity and viscosity, wettability, elastic surface with a film of water: the smaller the angle of impression from undercuts) will prevent the materi
even under 1 �m.•s memory, thixotropy, dimensional stability, tear contact, the better the material will adapt to the sur al from returning to its original shape and condition.
To prevent the transmission of infection, impres strength, hydrophilic behavior, thermal expansion, ace to be impressed (Fig 9-29). The balance between The ADA sets 2.5% as the limit of acceptability for
sions must be disinfected using a treatment that and application range. . cohesion and adhesion is an impotant factor i n permanent deformation'4 (Fig 9-31). .
determining a material's wettability. For example,
2 3
CHAP1' I
c
� Deformation 2.5%
c
9-3 1
Figs 9-25 and 9-26 Comparison of a tooth preparation and its cast developed from an accurate impression. Clinicians are generally convinced that die showing a divergence between the buccal and palatal walls (total occlusal convergence (TOC] angle) that resulted from an error during
an impression is a perfect copy of the prepared tooth. The impression material reproduces tooth preparations as accurately as possible, and preparation. Given the shape of the preparation. the restoration will be distorted because the elastic limit has been exceeded. Furthermore.
stone or epoxy resin casts have many clinical characteristics of the originaL However. it is impossible to obtain two identical impressions of because the anatomic shape of the canine has not been Ia ken 1nlo consideration in the design of this preparation. the dental technician wilt be
the same tooth. Fig 9-27 Polyether impression of a groove photographed at 50 x magnification. Fig 9-28 Impression of a preparation involving a unable to create a restoration that simulates the natural canine shape. Fig 9-31 Illustration of the 2.5% deformation accepted by the ADA. After
gold inlay at 24 < . The external and internal bevels demonstrate the precision of detail reproduction of the impression materials. Fig g_2g intense stress lie. removal from the oral cavity). the impression material has difficulty returning to its original shape.
Different angles of wettability for three polyethers with different viscosities, /let to righ) low. medium, and high. Fig 9-30 Silver-plated master
CHAP1' I
c
� Deformation 2.5%
c
9-3 1
Figs 9-25 and 9-26 Comparison of a tooth preparation and its cast developed from an accurate impression. Clinicians are generally convinced that die showing a divergence between the buccal and palatal walls (total occlusal convergence (TOC] angle) that resulted from an error during
an impression is a perfect copy of the prepared tooth. The impression material reproduces tooth preparations as accurately as possible, and preparation. Given the shape of the preparation. the restoration will be distorted because the elastic limit has been exceeded. Furthermore.
stone or epoxy resin casts have many clinical characteristics of the originaL However. it is impossible to obtain two identical impressions of because the anatomic shape of the canine has not been Ia ken 1nlo consideration in the design of this preparation. the dental technician wilt be
the same tooth. Fig 9-27 Polyether impression of a groove photographed at 50 x magnification. Fig 9-28 Impression of a preparation involving a unable to create a restoration that simulates the natural canine shape. Fig 9-31 Illustration of the 2.5% deformation accepted by the ADA. After
gold inlay at 24 < . The external and internal bevels demonstrate the precision of detail reproduction of the impression materials. Fig g_2g intense stress lie. removal from the oral cavity). the impression material has difficulty returning to its original shape.
Different angles of wettability for three polyethers with different viscosities, /let to righ) low. medium, and high. Fig 9-30 Silver-plated master
CHAPTER 9
. To exploit the maximum effect of elastic memory, memory of the impression material. Therefore, . er the lear strength will be. However, flexibility also preparations are more prone to tearing because of
the clinician must be aware of the proper techniques impression materials that require immediate invest increases the capacity for a material to permanently the greater likelihood of undercuts during tooth
for impression preservation, and especially the max ment should be avoided because they provide less deform (Fig 9-32). The material must be flexible preparation and I he elasticity of the gingival tissue.
imum time limit for pouring an impression. However, dimensional stability. Immediate investment com enough to maintain its shape during removal and Periodontal hemorrhage (which should never
the authors believe it is equally important that the promises the elastic memory and leads to more fre sufficiently viscose to accurately reproduce impres occur in this stage) also reduces tear strength. Blood
clinician avoid pouring the stone impression too quent internal distortions and deformations of the sion details. compromises the impression material's polymeriza
early. Waiting the necessary time before producing a stone cast. An operator can detect a low degree of tear tion since it fills up the space created for the impres
stone cast, even a few days, allows the elastic mem Stability continues to be an important focus of strength by using a microscope (see chapter 2) with sion material. Another aspect that can cause tears is
ory to develop fully.'B research on impression materials'•: studies have a good depth of field to look for any imperfections sharp edges, especially of rough preparations (Figs
demonstrated the stability of impression materials or alterations in the impression (Fig 9-33). 9-47 and 9-48).
in relation to the time elapsed before investing the Stress from impression removal from undercuts In clinical terms, tear strength depends mostly on
Thixotropy
impression with stoneJ • or with respect to disinfec can create a distortion wave in the impression and the thickness of the material i n the area of the
Thixotropy refers to a material's capacity to become tion techniques.'J Piwowarczyk et al3' studied six alter the shape and dimensions of the preparation. preparation and the finish line, as well as the type
more fluid when subjected to mechanical stimula silicones and two polyethers, using in vitro tests While some undercuts exist naturally in the mouth, of preparation. According to some authors,8·34 the
tion, such as compression when an impression is and a steel model. The dimensional stability among during tooth preparation clinicians must not create tear strength for impression materials can be classi
being taken. This property, which is common to the i mpression materials ranged from 11 to 19 �m additional undercuts that could afect the precision fied in the following descending order: polysulfides,
polyethers and few other materials, manifests each over a complete dental arch, demonstrating high of the restoration (Figs 9-34 to 9-37). An impression polyvinyl siloxanes, polyethers, and hydrocolloids.
time the low-viscosity detail materials placed along precision. Stability often depends on such condi of a perfect tooth preparation can therefore be com
the gingival sulcus are pressed by the high-viscosity tions as the amount of cross bonding that occurs promised by the presence of any undercuts in the
Hydrophilic behavior
support materials during tray positioning. The during the chemical reaction, loss of volatile com dental arch.
mechanical compression of high-viscosity material ponents (eg, alcohols) or water, and swelling due to Because teeth naturally taper sharply at the Hydrophilia is a material's capacity to absorb water
i ncreases the fluidity of low-viscosity material, which water absorption. cementoenamel junction, the deepest undercuts can and is attributed to the presence of free hydrogen
in turn flows more easily into thin cracks and areas oten be found in the area apical to the finish line bonds in the molecular chains. Hydrophilic materials
of the finish line and around the tooth structure (Fig 9-38). The horizontal gingival retraction that will absorb water, even i n the form of atmospheric
Tear strength
beyond the finish line. provides space for the impression material around humidity after removal from the mouth. Water
Tear strength is a material's capacity to resist dam the finish line must be kept to a minimum to avoid absorption can deform the i mpression and alter the
age (above all, breakage) even in the presence of complications. The result is a very thin impression in volume dimensions. The clinician can only take im
D i m ensional stability
undercuts when the impression is removed from the the area subjected to highest stress (Figs 9-39 and pressions with hydrophilic material in a d y environ
Dimensional stability refers to a material's capacity mouth.JJ-JS Tear strength is influenced by flexibility 9-40). According to Albers,J6 o.s mm is adequate ment area that is not subject to high temperatures.
to retain its shape over time and under any humid (compression deformation) and viscosity (the con horizontal gingival retraction for elastomers in gen Hydrophilic behavior, on the other hand, is a
ity or temperature conditions within a tolerance of sistency of the impression material); a delicate bal eral, while 1 mm is required for reversible hydrocol material's capacity to be unafected by the presence
0.2% (per ADA requirements).•• Investing the im ance between these two properties is required for a loids, given the properties of the impression materi of water, for example, when in contact with a moist
pression with stone immediately after it has been material to manifest maximum tear strength.8 als. A material with a high degree of tear strength surface, and depends on the presence of tensioac
taken can compensate for the relatively low dimen To overcome the stress of being removed from requires less gingival retraction than a material with tive substances. Thus. a material with hydrophilic
sional stability of some impression materials or the undercuts, an impression material must be highly a low degree of tear strength {Figs 9-41 to 9-46). behavior can adhere to preparations while the
possibility of water absorption or secretion. How flexible. Flexibility determines the amount of force The placement of the inish line can influence the impression sets, even if there are traces of moisture . .
ever, as noted earlier, immediate pouring of the that is required to remove the impression from the required amount of tear strength. lntracrevicular
stone cast prevents full development of the elastic mouth: the greater the degree of flexibility, the high- .
6
CHAPTER 9
. To exploit the maximum effect of elastic memory, memory of the impression material. Therefore, . er the lear strength will be. However, flexibility also preparations are more prone to tearing because of
the clinician must be aware of the proper techniques impression materials that require immediate invest increases the capacity for a material to permanently the greater likelihood of undercuts during tooth
for impression preservation, and especially the max ment should be avoided because they provide less deform (Fig 9-32). The material must be flexible preparation and I he elasticity of the gingival tissue.
imum time limit for pouring an impression. However, dimensional stability. Immediate investment com enough to maintain its shape during removal and Periodontal hemorrhage (which should never
the authors believe it is equally important that the promises the elastic memory and leads to more fre sufficiently viscose to accurately reproduce impres occur in this stage) also reduces tear strength. Blood
clinician avoid pouring the stone impression too quent internal distortions and deformations of the sion details. compromises the impression material's polymeriza
early. Waiting the necessary time before producing a stone cast. An operator can detect a low degree of tear tion since it fills up the space created for the impres
stone cast, even a few days, allows the elastic mem Stability continues to be an important focus of strength by using a microscope (see chapter 2) with sion material. Another aspect that can cause tears is
ory to develop fully.'B research on impression materials'•: studies have a good depth of field to look for any imperfections sharp edges, especially of rough preparations (Figs
demonstrated the stability of impression materials or alterations in the impression (Fig 9-33). 9-47 and 9-48).
in relation to the time elapsed before investing the Stress from impression removal from undercuts In clinical terms, tear strength depends mostly on
Thixotropy
impression with stoneJ • or with respect to disinfec can create a distortion wave in the impression and the thickness of the material i n the area of the
Thixotropy refers to a material's capacity to become tion techniques.'J Piwowarczyk et al3' studied six alter the shape and dimensions of the preparation. preparation and the finish line, as well as the type
more fluid when subjected to mechanical stimula silicones and two polyethers, using in vitro tests While some undercuts exist naturally in the mouth, of preparation. According to some authors,8·34 the
tion, such as compression when an impression is and a steel model. The dimensional stability among during tooth preparation clinicians must not create tear strength for impression materials can be classi
being taken. This property, which is common to the i mpression materials ranged from 11 to 19 �m additional undercuts that could afect the precision fied in the following descending order: polysulfides,
polyethers and few other materials, manifests each over a complete dental arch, demonstrating high of the restoration (Figs 9-34 to 9-37). An impression polyvinyl siloxanes, polyethers, and hydrocolloids.
time the low-viscosity detail materials placed along precision. Stability often depends on such condi of a perfect tooth preparation can therefore be com
the gingival sulcus are pressed by the high-viscosity tions as the amount of cross bonding that occurs promised by the presence of any undercuts in the
Hydrophilic behavior
support materials during tray positioning. The during the chemical reaction, loss of volatile com dental arch.
mechanical compression of high-viscosity material ponents (eg, alcohols) or water, and swelling due to Because teeth naturally taper sharply at the Hydrophilia is a material's capacity to absorb water
i ncreases the fluidity of low-viscosity material, which water absorption. cementoenamel junction, the deepest undercuts can and is attributed to the presence of free hydrogen
in turn flows more easily into thin cracks and areas oten be found in the area apical to the finish line bonds in the molecular chains. Hydrophilic materials
of the finish line and around the tooth structure (Fig 9-38). The horizontal gingival retraction that will absorb water, even i n the form of atmospheric
Tear strength
beyond the finish line. provides space for the impression material around humidity after removal from the mouth. Water
Tear strength is a material's capacity to resist dam the finish line must be kept to a minimum to avoid absorption can deform the i mpression and alter the
age (above all, breakage) even in the presence of complications. The result is a very thin impression in volume dimensions. The clinician can only take im
D i m ensional stability
undercuts when the impression is removed from the the area subjected to highest stress (Figs 9-39 and pressions with hydrophilic material in a d y environ
Dimensional stability refers to a material's capacity mouth.JJ-JS Tear strength is influenced by flexibility 9-40). According to Albers,J6 o.s mm is adequate ment area that is not subject to high temperatures.
to retain its shape over time and under any humid (compression deformation) and viscosity (the con horizontal gingival retraction for elastomers in gen Hydrophilic behavior, on the other hand, is a
ity or temperature conditions within a tolerance of sistency of the impression material); a delicate bal eral, while 1 mm is required for reversible hydrocol material's capacity to be unafected by the presence
0.2% (per ADA requirements).•• Investing the im ance between these two properties is required for a loids, given the properties of the impression materi of water, for example, when in contact with a moist
pression with stone immediately after it has been material to manifest maximum tear strength.8 als. A material with a high degree of tear strength surface, and depends on the presence of tensioac
taken can compensate for the relatively low dimen To overcome the stress of being removed from requires less gingival retraction than a material with tive substances. Thus. a material with hydrophilic
sional stability of some impression materials or the undercuts, an impression material must be highly a low degree of tear strength {Figs 9-41 to 9-46). behavior can adhere to preparations while the
possibility of water absorption or secretion. How flexible. Flexibility determines the amount of force The placement of the inish line can influence the impression sets, even if there are traces of moisture . .
ever, as noted earlier, immediate pouring of the that is required to remove the impression from the required amount of tear strength. lntracrevicular
stone cast prevents full development of the elastic mouth: the greater the degree of flexibility, the high- .
6
Fig 9-32 Polyether impression of natural teeth (lmpregum Penta Soft HB and LB. 3M ESPEJ. The tear strength is primarily evident in the interproximal
areas. which remain unchanged after removal from lhe mouth. F1g 9-33 lower degree of tear strength i n the buccal aspect of lhe Impression. The
impression of the sulcus was damaged dunng removal from lhe oral cavity. The lack of detail of the intact tooth structure apical to the finish line will
hamper the technician in interpreting the position and extension of the f1n1sh line. Figs g-4and g -35 Example of poorly executed tooth preparations. An
impression has been taken and Invested to create a working cast on which four complete crowns can be made. The most troubling aspect is that the
impression was sent to the lab even with serious defects (arrow} m the design and parallelism of the prepared Ieeth lnaccurams 1n lhe impression
are manifest in the numerous stnpes caused by the tensile stress placed on the impresSIOn material. Though errors are both conceptual and opera
Ilona!. the greatest fallacy lies in thinking that a dental technician can produce an accurate restoration from such an ImpresSIOn Figs 9-36 and 9-37
Magnified views of another case, the working cast and clin1cal situation. Note the undercuts caused by incorrect tooth preparation. w1th areas that are
clearly inadequate in terms of thickness and finishing. Figs g -38 Clear and deta�led fin1sh line in the interproximal area. Fig g -3g Ev1dence of excessive
ging1val retraction. Although this impression 1s correct. 11 is too thick at the cervical margin. Fig g-40 Evidence of minimal gingival deflection. The thin
width and height of the intact tooth structure apical to the fmish line is typical of impressions taken using the single-cord lechn1que. A thin impres
sion in this area can d1stort easily during pouring and preclude the creation of more lhan one casl. Figs 9-41 and g-42 Using a microscope. a dental
technician reinforces the outside impression border of the intact tooth structure beyond the finish line with a thin line of inert wax. I n this instance.
the thin width and height of the impression beyond the finish line facilitates th1s operation. Once the border has been reinforced. the impression can
be used to pour several precision casts.
211 279
Fig 9-32 Polyether impression of natural teeth (lmpregum Penta Soft HB and LB. 3M ESPEJ. The tear strength is primarily evident in the interproximal
areas. which remain unchanged after removal from lhe mouth. F1g 9-33 lower degree of tear strength i n the buccal aspect of lhe Impression. The
impression of the sulcus was damaged dunng removal from lhe oral cavity. The lack of detail of the intact tooth structure apical to the finish line will
hamper the technician in interpreting the position and extension of the f1n1sh line. Figs g-4and g -35 Example of poorly executed tooth preparations. An
impression has been taken and Invested to create a working cast on which four complete crowns can be made. The most troubling aspect is that the
impression was sent to the lab even with serious defects (arrow} m the design and parallelism of the prepared Ieeth lnaccurams 1n lhe impression
are manifest in the numerous stnpes caused by the tensile stress placed on the impresSIOn material. Though errors are both conceptual and opera
Ilona!. the greatest fallacy lies in thinking that a dental technician can produce an accurate restoration from such an ImpresSIOn Figs 9-36 and 9-37
Magnified views of another case, the working cast and clin1cal situation. Note the undercuts caused by incorrect tooth preparation. w1th areas that are
clearly inadequate in terms of thickness and finishing. Figs g -38 Clear and deta�led fin1sh line in the interproximal area. Fig g -3g Ev1dence of excessive
ging1val retraction. Although this impression 1s correct. 11 is too thick at the cervical margin. Fig g-40 Evidence of minimal gingival deflection. The thin
width and height of the intact tooth structure apical to the fmish line is typical of impressions taken using the single-cord lechn1que. A thin impres
sion in this area can d1stort easily during pouring and preclude the creation of more lhan one casl. Figs 9-41 and g-42 Using a microscope. a dental
technician reinforces the outside impression border of the intact tooth structure beyond the finish line with a thin line of inert wax. I n this instance.
the thin width and height of the impression beyond the finish line facilitates th1s operation. Once the border has been reinforced. the impression can
be used to pour several precision casts.
211 279
CHAPTER 9
. Thermal expansion nents, base paste and catalyst, are measured out in
a ratio recommended by the manufacturer using var
The ADA has determined that a coefficient of thermal ious extrusion systems and placed on a suitable
expansion that is less than 2% is acceptable for mixing surface. It is impossible for the operator to
impression materials.'• Shifts of 2o°C can affect this mix the two components so that all of the material
coeficient, so clinicians must consider how and is activated at the same time and thus i n the same
where impressions are stored. Purk et al37 found stage of chemical reaction. During the plastic stage,
that at the upper and lower limits of extreme tem the material is kneaded or mixed and, because the
peratures (66°C and -to0C) impression materials chemical chains are still open, the material can be
experiences distortions, while Corso et al38 found no gently seated in the mouth to take an impression. In
9-43 9-4 4
significant dimensional alterations for temperatures the elastic stage, the chains are closed and the
ranging between 4°C and 40°C. material is less malleable.
The operator must know working and setting
times of the impression materials and keep the two
Evaluating a p p lication range
stages absolutely separate. An impression must be
Using impression materials with a versatile applica taken shortly after mixing the material, because
tion range makes clinical procedures easier, reduces once the chemical chains close, the i mpression
the number of materials used, and thus optimizes material cannot correctly adapt and record shape
the material cost and yield (Figs 9-49 to 9-51). and details of the patient's mouth. If a clinician tries
Evaluation of the application range includes a con to take an impression with material already in the
sideration of the characteristics discussed so far and elastic stage, it tends to return to its original shape
of the compatibility with various i nvestment materi after being removed from the mouth.'
als (eg, stone, epoxy resins, polyurethane resins) or For several years, equipment has been available
techniques (Figs 9-52 to 9-54). to mechanically blend impression materials packaged
Each impression material is compatible with cer in vacuum-packed cartridges. During extrusion, the
tain i nvestment materials used to pour the master base paste and catalyst are blended in the proper
cast; for example, hydrocolloids are incompatible quantities and for the correct amount of time.
with electroplating. Certain materials also are con Mechanical mixing offers many conveniences,39 in
traindicated for intracrevicular preparations. Thus, in cluding a faster mixing speed, use of less material,
choosing a material, it is important to assess the less air incorporated into the mixture, exact mixing
range of application in order to limit the amount of ratios, and the assurance that all of the impression
i nventory kept in storage and simplify the handling material is in the same stage (Figs 9-55 to 9-57). The
procedures (eg, paste mixing, working times, expira disadvantage, according to Keck,4° is that "materials
tion dates) of the impression materials. mixed automatically have 4% less tear strength than
those mixed manually." Figs g-43 and g-44 Wax reinforcement of the border makes the finish line more prominent on the plaster cast and fac i litates the difficult oper
When selecting an impression material, the clini· ation of trimming the cast. However. during structural evaluation with the ceramic in the bisque-bake stage. the clinician must take an elas
M ixing i m pression materials tomeric impression to establish the correct relationship with the nonretracted gingiva (instead of the reflection typical of the impression
cian must be aware of all properties and compati stage). Figs g-45 and g-46 To avoid taking another impression. the wax can be removed easily and the relationship with the gingiva reproduced
Manual mixing of impression material has always in a new cast. Figs 9-47 and 9-48 Excessive roughness of the tooth preparations. seen at the cervical margin and along the axial walls. can tear
bilities. An impression material must ofer a high re
the impression by increasing the resistance required to release the impression material from the oral cavity. Both impressions. however. sat
presented problems for operators. The two compo- sistance to tearing and deformation, accurate three- .. isfy basic clinical criteria.
G 11
CHAPTER 9
. Thermal expansion nents, base paste and catalyst, are measured out in
a ratio recommended by the manufacturer using var
The ADA has determined that a coefficient of thermal ious extrusion systems and placed on a suitable
expansion that is less than 2% is acceptable for mixing surface. It is impossible for the operator to
impression materials.'• Shifts of 2o°C can affect this mix the two components so that all of the material
coeficient, so clinicians must consider how and is activated at the same time and thus i n the same
where impressions are stored. Purk et al37 found stage of chemical reaction. During the plastic stage,
that at the upper and lower limits of extreme tem the material is kneaded or mixed and, because the
peratures (66°C and -to0C) impression materials chemical chains are still open, the material can be
experiences distortions, while Corso et al38 found no gently seated in the mouth to take an impression. In
9-43 9-4 4
significant dimensional alterations for temperatures the elastic stage, the chains are closed and the
ranging between 4°C and 40°C. material is less malleable.
The operator must know working and setting
times of the impression materials and keep the two
Evaluating a p p lication range
stages absolutely separate. An impression must be
Using impression materials with a versatile applica taken shortly after mixing the material, because
tion range makes clinical procedures easier, reduces once the chemical chains close, the i mpression
the number of materials used, and thus optimizes material cannot correctly adapt and record shape
the material cost and yield (Figs 9-49 to 9-51). and details of the patient's mouth. If a clinician tries
Evaluation of the application range includes a con to take an impression with material already in the
sideration of the characteristics discussed so far and elastic stage, it tends to return to its original shape
of the compatibility with various i nvestment materi after being removed from the mouth.'
als (eg, stone, epoxy resins, polyurethane resins) or For several years, equipment has been available
techniques (Figs 9-52 to 9-54). to mechanically blend impression materials packaged
Each impression material is compatible with cer in vacuum-packed cartridges. During extrusion, the
tain i nvestment materials used to pour the master base paste and catalyst are blended in the proper
cast; for example, hydrocolloids are incompatible quantities and for the correct amount of time.
with electroplating. Certain materials also are con Mechanical mixing offers many conveniences,39 in
traindicated for intracrevicular preparations. Thus, in cluding a faster mixing speed, use of less material,
choosing a material, it is important to assess the less air incorporated into the mixture, exact mixing
range of application in order to limit the amount of ratios, and the assurance that all of the impression
i nventory kept in storage and simplify the handling material is in the same stage (Figs 9-55 to 9-57). The
procedures (eg, paste mixing, working times, expira disadvantage, according to Keck,4° is that "materials
tion dates) of the impression materials. mixed automatically have 4% less tear strength than
those mixed manually." Figs g-43 and g-44 Wax reinforcement of the border makes the finish line more prominent on the plaster cast and fac i litates the difficult oper
When selecting an impression material, the clini· ation of trimming the cast. However. during structural evaluation with the ceramic in the bisque-bake stage. the clinician must take an elas
M ixing i m pression materials tomeric impression to establish the correct relationship with the nonretracted gingiva (instead of the reflection typical of the impression
cian must be aware of all properties and compati stage). Figs g-45 and g-46 To avoid taking another impression. the wax can be removed easily and the relationship with the gingiva reproduced
Manual mixing of impression material has always in a new cast. Figs 9-47 and 9-48 Excessive roughness of the tooth preparations. seen at the cervical margin and along the axial walls. can tear
bilities. An impression material must ofer a high re
the impression by increasing the resistance required to release the impression material from the oral cavity. Both impressions. however. sat
presented problems for operators. The two compo- sistance to tearing and deformation, accurate three- .. isfy basic clinical criteria.
G 11
I
FIG 9-55 AG 9-56
C O R R E C T B A S E - C A T A L Y S T M I X I N G R A T I 0
FIG 9-57
Figs 9-49 o 9-51 Versatile Impression materials can be used to take Impressions of various restorations. including inlays. indirect gold posts Fig g.55 Pentamix II unit 13M ESPEI for mixing impression materials.
and cores. and complete crowns. In the management of a professional dental office. material versatility is a considerable advantage for stor
Fig g-56 Garant dispenser 13M ESPEI.
age and handling F1gs 9-52 o 9-4 Impression materials must be compatible w1th the other matenals. such as electroplating silver. plaster.
and polyurethane or epoxy reSin Fig 9-57 Impression material mixed using the Pentamix II.
2 23
I
FIG 9-55 AG 9-56
C O R R E C T B A S E - C A T A L Y S T M I X I N G R A T I 0
FIG 9-57
Figs 9-49 o 9-51 Versatile Impression materials can be used to take Impressions of various restorations. including inlays. indirect gold posts Fig g.55 Pentamix II unit 13M ESPEI for mixing impression materials.
and cores. and complete crowns. In the management of a professional dental office. material versatility is a considerable advantage for stor
Fig g-56 Garant dispenser 13M ESPEI.
age and handling F1gs 9-52 o 9-4 Impression materials must be compatible w1th the other matenals. such as electroplating silver. plaster.
and polyurethane or epoxy reSin Fig 9-57 Impression material mixed using the Pentamix II.
2 23
CHAPTER 9
Custom I mpression Trays and I mpression Materials
. dimensional reproduction, and dimensional stability. Reversible hydrocolloids are neither flexible nor . on clothing. Pouring of the cast demands scrupulous Polyethers
The ability to reproduce precise surface details is viscous, and this lack of elastic memory and attention because the material's high flexibility lends
necessary for an accurate restoration margin and thixotropy is associated with fragility at the level of itself to easy deformation, and the material contin· Introduced in 1965, polyethers ofer several practical
depends largely on the luidity of the material. When the gingival sulcus. As a result. the clinician will ues to react even after removal from the mouth and advantages, such as high dimensional stability and
an i mpression material has these characteristics, the have difficulty identifying the cervical limits and will ongoing reactions that produce alcohols. rapid solidification, along with excellent recording of
likelihood of obtaining a suitable impression increases. be forced to retract the gingiva more extensively In the authors' view, polysufides are unsuitable the cervical margins and no requirement for special
than is generally required with other elastomers. for fixed and removable restorations because of apparatus. I n addition, they have a good shelf life
Because they have the lowest tear strength,8 re· their high rate of distortion, which is well masked by (2 years) and may be poured up to 7 days after
TYPES O F I M PRESSION MATERIAL
versible hydrocolloids are not recommended for their flexibility. The impressions appear to be accu· impression taking without any concern, allowing the
intracrevicular preparations, which are often called rate but actually correspond little to the clinical sit· impression to set completely for maximum elastic
Reversible hydrocolloi ds for in patients who seek high-quality esthetics. uation they are intended to reproduce. memory.
Because of the need for immediate pouring, the Today, polyethers are represented by an assort·
Reversible hydrocolloid materials, which irst appeared material's elastic memoy, and hence its elastic ment of materials with varying degrees of viscosity
Condensation silicones
on the market in 1925, are made of marine algae recovery, cannot be exploited. For these reasons, and hardness, so that they are extremely versatile
(agar). These materials were among the first to be and especially given the considerable horizontal The first elastomers, condensation silicones were with a wide range of application in clinical practice.
used to make precision impressions in prosthodon retraction they require, the authors believe hydro· introduced in 1955, 10 years before the first poly· They are composed of a base paste made of poly
tics, and they remain popular today because of their colloids are now obsolete for clinical use. ethers became available. At the time, they were ether imine-terminated prepolymer, i nert fillers,
relatively high degree of precision and low cost. widely accepted by dental professionals and contin· emollients, pigments, and aromatic substances. The
Reversible hydrocolloids present unique advan· ue to be used frequently in clinical practice. Con· catalyst is composed of an ester derivative of aro·
Polysulfides
tages related to their chemical composition: They densation silicones ofer the advantages of requiring matic sulphonic acid, inert illers, emollients, and
tolerate slight humidity at the gingival sulcus, have Polysulfide materials became available in the 1950s, no custom tray or other special equipment, provid pigments. The additives and illers are essentially
a pleasant taste, and do not leave indelible marks. principally as a precision impression for a complete ing a good record of the cervical limits because of inorganic and consist of strongly dispersed silica
In addition, a custom tray is not needed for taking denture, and later extended to fixed prostheses. their high tear strength, and exhibiting good elastic and fossil flour, which are responsible for the mate
impressions. Besides these rheologic characteristics, These materials have high tear strengthJ4 , J 5 owing recovery and a reasonable degree of versatility, as rials' increased final rigidity, dimensional stability
other advantages of these materials include a low to their extraordinay, even excessive, flexibility, well as a relatively low cost. after removal from the mouth, and thixotropy.
cost per impression, a long shelf life, and the rela which produces a highly detailed impression. They Unfortunately, condensation silicones are hydro· The d iferent consistencies found among poly·
tive ease of pouring with the investment materials. provide apparently correct impressions that exhibit phobic, and their use requires rigorous attention to ethers, according to the ISO 4823 technical specii·
Reversible hydrocolloids also have some disad good detail at the cervical limits, can be treated with keep the gingival sulcus d y during impression tak· cations, are shown i n Table 9-1. An analysis of the
vantages, including the need for an expensive piece electroplating for casting, and have a long shelf life. ing. Because they have inadequate dimensional sta· table illustrates that the various consistencies of
of equipment for conditioning the materials (special Unfortunately, excessive flexibility and insuficient bility, the cast must be poured within 20 minutes, polyethers determine their applications. For exam
water trays for boiling and cooling, and a humidor hardness result in elevated marginal distortion, and care must be taken to avoid deformation, which ple, the high-viscosity polyethers are indicated for
for impression storage), and they pose a risk of which renders polysulfide impressions unsuitable for can occur easily. suppot functions, whereas the low-viscosity materi
scalding the patient i f handled improperly. Moreover, making accurate restorations. Other disadvantages The demand for these materials remains steady als reproduce greater detail. Their wide variability
because the materials have the capacity to absorb include the need to make a custom tray to overcome today primarily because they are frequently used in and compatibility permit clinicians to use diferent
water molecules while the impression is being the most pronounced undercuts, a high degree of the putty-wash technique, which involves making a polyether materials according to the clinical situa·
taken, the cast must be poured immediately (within sensitivity to heat, and a pronounced hydrophobia double impression. In the authors' opinion, howev tion and its requisites; the clinician can decide
a maximum time of 15 minutes') . Consequently, that requires a completely dry gingival sulcus for er, their dimensional instability makes them unsuit· which material to use without compromising proper
electroplating techniques and epoxy resins cannot impression taking. Furthermore, polysulfide materials able for current clinical needs. clinical procedure. �
be used for casting. have a disagreeable odor and leave indelible stains �
5
CHAPTER 9
. dimensional reproduction, and dimensional stability. Reversible hydrocolloids are neither flexible nor . on clothing. Pouring of the cast demands scrupulous Polyethers
The ability to reproduce precise surface details is viscous, and this lack of elastic memory and attention because the material's high flexibility lends
necessary for an accurate restoration margin and thixotropy is associated with fragility at the level of itself to easy deformation, and the material contin· Introduced in 1965, polyethers ofer several practical
depends largely on the luidity of the material. When the gingival sulcus. As a result. the clinician will ues to react even after removal from the mouth and advantages, such as high dimensional stability and
an i mpression material has these characteristics, the have difficulty identifying the cervical limits and will ongoing reactions that produce alcohols. rapid solidification, along with excellent recording of
likelihood of obtaining a suitable impression increases. be forced to retract the gingiva more extensively In the authors' view, polysufides are unsuitable the cervical margins and no requirement for special
than is generally required with other elastomers. for fixed and removable restorations because of apparatus. I n addition, they have a good shelf life
Because they have the lowest tear strength,8 re· their high rate of distortion, which is well masked by (2 years) and may be poured up to 7 days after
TYPES O F I M PRESSION MATERIAL
versible hydrocolloids are not recommended for their flexibility. The impressions appear to be accu· impression taking without any concern, allowing the
intracrevicular preparations, which are often called rate but actually correspond little to the clinical sit· impression to set completely for maximum elastic
Reversible hydrocolloi ds for in patients who seek high-quality esthetics. uation they are intended to reproduce. memory.
Because of the need for immediate pouring, the Today, polyethers are represented by an assort·
Reversible hydrocolloid materials, which irst appeared material's elastic memoy, and hence its elastic ment of materials with varying degrees of viscosity
Condensation silicones
on the market in 1925, are made of marine algae recovery, cannot be exploited. For these reasons, and hardness, so that they are extremely versatile
(agar). These materials were among the first to be and especially given the considerable horizontal The first elastomers, condensation silicones were with a wide range of application in clinical practice.
used to make precision impressions in prosthodon retraction they require, the authors believe hydro· introduced in 1955, 10 years before the first poly· They are composed of a base paste made of poly
tics, and they remain popular today because of their colloids are now obsolete for clinical use. ethers became available. At the time, they were ether imine-terminated prepolymer, i nert fillers,
relatively high degree of precision and low cost. widely accepted by dental professionals and contin· emollients, pigments, and aromatic substances. The
Reversible hydrocolloids present unique advan· ue to be used frequently in clinical practice. Con· catalyst is composed of an ester derivative of aro·
Polysulfides
tages related to their chemical composition: They densation silicones ofer the advantages of requiring matic sulphonic acid, inert illers, emollients, and
tolerate slight humidity at the gingival sulcus, have Polysulfide materials became available in the 1950s, no custom tray or other special equipment, provid pigments. The additives and illers are essentially
a pleasant taste, and do not leave indelible marks. principally as a precision impression for a complete ing a good record of the cervical limits because of inorganic and consist of strongly dispersed silica
In addition, a custom tray is not needed for taking denture, and later extended to fixed prostheses. their high tear strength, and exhibiting good elastic and fossil flour, which are responsible for the mate
impressions. Besides these rheologic characteristics, These materials have high tear strengthJ4 , J 5 owing recovery and a reasonable degree of versatility, as rials' increased final rigidity, dimensional stability
other advantages of these materials include a low to their extraordinay, even excessive, flexibility, well as a relatively low cost. after removal from the mouth, and thixotropy.
cost per impression, a long shelf life, and the rela which produces a highly detailed impression. They Unfortunately, condensation silicones are hydro· The d iferent consistencies found among poly·
tive ease of pouring with the investment materials. provide apparently correct impressions that exhibit phobic, and their use requires rigorous attention to ethers, according to the ISO 4823 technical specii·
Reversible hydrocolloids also have some disad good detail at the cervical limits, can be treated with keep the gingival sulcus d y during impression tak· cations, are shown i n Table 9-1. An analysis of the
vantages, including the need for an expensive piece electroplating for casting, and have a long shelf life. ing. Because they have inadequate dimensional sta· table illustrates that the various consistencies of
of equipment for conditioning the materials (special Unfortunately, excessive flexibility and insuficient bility, the cast must be poured within 20 minutes, polyethers determine their applications. For exam
water trays for boiling and cooling, and a humidor hardness result in elevated marginal distortion, and care must be taken to avoid deformation, which ple, the high-viscosity polyethers are indicated for
for impression storage), and they pose a risk of which renders polysulfide impressions unsuitable for can occur easily. suppot functions, whereas the low-viscosity materi
scalding the patient i f handled improperly. Moreover, making accurate restorations. Other disadvantages The demand for these materials remains steady als reproduce greater detail. Their wide variability
because the materials have the capacity to absorb include the need to make a custom tray to overcome today primarily because they are frequently used in and compatibility permit clinicians to use diferent
water molecules while the impression is being the most pronounced undercuts, a high degree of the putty-wash technique, which involves making a polyether materials according to the clinical situa·
taken, the cast must be poured immediately (within sensitivity to heat, and a pronounced hydrophobia double impression. In the authors' opinion, howev tion and its requisites; the clinician can decide
a maximum time of 15 minutes') . Consequently, that requires a completely dry gingival sulcus for er, their dimensional instability makes them unsuit· which material to use without compromising proper
electroplating techniques and epoxy resins cannot impression taking. Furthermore, polysulfide materials able for current clinical needs. clinical procedure. �
be used for casting. have a disagreeable odor and leave indelible stains �
5
CHAPTER 9
. Hardness. measured in shore units, is tested over

time because it increases over time.•• Table 9-2
and, together with polyethers, are more precise,
more stable, and thus by far the most frequently
[ TABLE 9-1 Consistencies of polyeth e rs_____________!
__
demonstrates that the characteristics produced by used material for impression taking in clinical
Material Consistency (mm)
--
-
different components, especially the fillers, can make prosthodontics. Their primary advantage is versat ili·
Permadyne Light Body 40
a material more suitable for certain functions. For ty: they can be used with many different techniques,
Permadyne Heavy Body 33
example, lmpregum Penta has very high rigidity after including the double impression (putty-wash) tech·
lmpregum Penta 33
24 hours and is therefore ideal for taking a precision nique and the one-step/one-. two-. or three-paste lmpregum Penta Soft 35
impression for implant-supported prostheses. techniques. In addition to excellent precision and l m pregum DuoSot, light body 42
The advantages that particularly distinguish poly recording of marginal details, their other advantages l mpregum DuoSoft, heavy body 32
ethers are wettability. which makes them more com include wettability, excellent elasticity, and pleasant
patible with diverse surfaces; thixotropy, which makes odor and appearance. Polyvinyl siloxanes make it
the materials more nuid and increases their capacity possible for several casts to be made from the same
TABLE 9-2 Hardness of polyether over time
to reproduce details; and good hydrophilic behavior, impression, though only the first one will have the
which allows them to function optimally even in the quality of a master cast (the subsequent i mpres Hardness (shore)
presence of slight humidity in the gingival sulcus. sions will have lost the detail or the intact tooth Material After 15 min After 1 h After 24 h
Among the disadvantages are the necessity to structure beyond the finish line). Moreover, they do
Permadyne Light Body 33 45 53
make a custom impression tray, to which polyethers not require special equipment, are easy to store,
Permadyne Heavy Body 46 55 sa
adhere poorly, particularly when a specific adhesive allow for electroplating, and are easy to mix into a lmpregum Penta Soft 40 47 so
is used incorrectly. High-viscosity polyethers (eg, lm· paste. l m pregum Penta 46 55 6!
pregum Penta, Permadyne Heavy Body; 3M ESPE) are Among their drawbacks are difficulty in pouring,
quite rigid, especially with respect to removal from high cost, and considerable hydrophobia, which
the mouth. Thus, to avoid complications such as frac requires a completely dry gingival sulcus. Further·
tures of weak teeth or avulsion of teeth with little more, the operator cannot wear latex gloves while
periodontal support, the undercuts must be careful manipulating polyvinyl silxanes because the reticu
ly filled in with stone paste, provisional cement, or lar reaction of the chain polymerization Is inhibited
materials with low consistency (eg, Permadyne Light by latex.•' .. I M PRESSION TECH N I QU ES called regular, so that both hardness and viscosity
Body or lmpregum DuoSoft light body; 3M. ESPE). Polyvinyl siloxanes have been available since may be obtained from one material.
Other negative aspects unrelated to clinical outcome 1975 in various consistencies and with various char It is generally believed that various viscosities of Clinicians distinguish between impression tech
are cost, indelible staining of clothing, and marked acteristics, depending on their composition. In their impression materials correspond to different quali niques that involve the use of a single material and
sensitivity to ultraviolet light and excessive heat. medium-, high-, and very-high-viscosity versions, they ties and applications. All impression materials are those that use two or more materials simultaneous
are used as support materials, while low-viscosity classified either as a support material or a detail ly. Among the various impression techniques are
polyvinyl siloxanes are used to reproduce details. .. material. Support materials must exhibit elevated the one-step/one-paste technique, the one-step/two
Polvinyl siloxanes
hardness (greater than s o shore units) for stability paste technique, the one-step/three-paste technique,
Polyvinyl siloxanes, also known as addition silicones, and high viscosity (35 mm or less). Detail materials and the two-step/two-paste technique.
are among the most recent generation of elastomers must be highly nuid to reproduce minute details and
therefore must have a low viscosity and a hardness
One-step/one- paste technique
value that is not excessive. To meet the varied needs
of clinical operators, manufacturers have also intra· T h e one-step/one-paste technique is t h e easiest and
duced materials with medium characteristics. often perhaps the most common technique used for fixed ..
17
CHAPTER 9
. Hardness. measured in shore units, is tested over

time because it increases over time.•• Table 9-2
and, together with polyethers, are more precise,
more stable, and thus by far the most frequently
[ TABLE 9-1 Consistencies of polyeth e rs_____________!
__
demonstrates that the characteristics produced by used material for impression taking in clinical
Material Consistency (mm)
--
-
different components, especially the fillers, can make prosthodontics. Their primary advantage is versat ili·
Permadyne Light Body 40
a material more suitable for certain functions. For ty: they can be used with many different techniques,
Permadyne Heavy Body 33
example, lmpregum Penta has very high rigidity after including the double impression (putty-wash) tech·
lmpregum Penta 33
24 hours and is therefore ideal for taking a precision nique and the one-step/one-. two-. or three-paste lmpregum Penta Soft 35
impression for implant-supported prostheses. techniques. In addition to excellent precision and l m pregum DuoSot, light body 42
The advantages that particularly distinguish poly recording of marginal details, their other advantages l mpregum DuoSoft, heavy body 32
ethers are wettability. which makes them more com include wettability, excellent elasticity, and pleasant
patible with diverse surfaces; thixotropy, which makes odor and appearance. Polyvinyl siloxanes make it
the materials more nuid and increases their capacity possible for several casts to be made from the same
TABLE 9-2 Hardness of polyether over time
to reproduce details; and good hydrophilic behavior, impression, though only the first one will have the
which allows them to function optimally even in the quality of a master cast (the subsequent i mpres Hardness (shore)
presence of slight humidity in the gingival sulcus. sions will have lost the detail or the intact tooth Material After 15 min After 1 h After 24 h
Among the disadvantages are the necessity to structure beyond the finish line). Moreover, they do
Permadyne Light Body 33 45 53
make a custom impression tray, to which polyethers not require special equipment, are easy to store,
Permadyne Heavy Body 46 55 sa
adhere poorly, particularly when a specific adhesive allow for electroplating, and are easy to mix into a lmpregum Penta Soft 40 47 so
is used incorrectly. High-viscosity polyethers (eg, lm· paste. l m pregum Penta 46 55 6!
pregum Penta, Permadyne Heavy Body; 3M ESPE) are Among their drawbacks are difficulty in pouring,
quite rigid, especially with respect to removal from high cost, and considerable hydrophobia, which
the mouth. Thus, to avoid complications such as frac requires a completely dry gingival sulcus. Further·
tures of weak teeth or avulsion of teeth with little more, the operator cannot wear latex gloves while
periodontal support, the undercuts must be careful manipulating polyvinyl silxanes because the reticu
ly filled in with stone paste, provisional cement, or lar reaction of the chain polymerization Is inhibited
materials with low consistency (eg, Permadyne Light by latex.•' .. I M PRESSION TECH N I QU ES called regular, so that both hardness and viscosity
Body or lmpregum DuoSoft light body; 3M. ESPE). Polyvinyl siloxanes have been available since may be obtained from one material.
Other negative aspects unrelated to clinical outcome 1975 in various consistencies and with various char It is generally believed that various viscosities of Clinicians distinguish between impression tech
are cost, indelible staining of clothing, and marked acteristics, depending on their composition. In their impression materials correspond to different quali niques that involve the use of a single material and
sensitivity to ultraviolet light and excessive heat. medium-, high-, and very-high-viscosity versions, they ties and applications. All impression materials are those that use two or more materials simultaneous
are used as support materials, while low-viscosity classified either as a support material or a detail ly. Among the various impression techniques are
polyvinyl siloxanes are used to reproduce details. .. material. Support materials must exhibit elevated the one-step/one-paste technique, the one-step/two
Polvinyl siloxanes
hardness (greater than s o shore units) for stability paste technique, the one-step/three-paste technique,
Polyvinyl siloxanes, also known as addition silicones, and high viscosity (35 mm or less). Detail materials and the two-step/two-paste technique.
are among the most recent generation of elastomers must be highly nuid to reproduce minute details and
therefore must have a low viscosity and a hardness
One-step/one- paste technique
value that is not excessive. To meet the varied needs
of clinical operators, manufacturers have also intra· T h e one-step/one-paste technique is t h e easiest and
duced materials with medium characteristics. often perhaps the most common technique used for fixed ..
17
CHAPTER 9
. prostheses. Its popularity probably results from its lure. Low-viscosity materials can be applied in min
simplicity; it uses a single material with one consis imal amounts directly along the finish line. using a
tency at one time (Figs 9·58 to 9-60). Moreover, both syringe equipped with tips suitable for optimal
functions required to obtain a precision impression extrusion and adaptation. Manufacturer kits include
(ie. detail and support) are carried out using only preformed tips with standard-diameter openings (Fig
one material of medium to high consistency (eg, reg 9·66). but these can be replaced by syringe tips with
ular for a polyvinyl siloxane. soft or hard for a poly diferent angles and diameters (Fig 9-67).
ether). Unfortunately, while the support function can When using the single-cord method of retraction.
be performed just as adequately with a medium- or which is their preferred method. the authors choose
regular-viscosity material, the same cannot be said a syringe tip with a very small opening that fits the
for the detail function, which is severely compro minimal space available, both horizontally and ver
mised in the authors' opinion. This technique leads tically (Fig 9-68). During extrusion, they use adapt·
to difficulty in reproducing adequate detail of the able tips for reaching the palatal and lingual sur
finish line preparation without extensive displace faces of the teeth. With suitably curved tips, the
ment of soft tissue. and thus the cervical margins operator can ensure that the impression material
are not always clear and precise. contacts the critical areas to be reproduced in the
The authors firmly prefer the other techniques impression. Tips produced by Anthogyr or Centrix
over this one because they allow for the use of permit the operator to modiy the diameter and
materials of diferent consistencies for each function angle of curvature without creating undesirable bot
(detail or support) i n the same plastic phase. The tlenecks in the extrusion channel. Tips that can be
clinician never allows one of the materials to hard adapted to suit the clinical case and the operator's
en before the other (Figs 9-61 to 9·65). working position allow easy application in areas where
access is otherwise difficult (Figs 9-69 and 9-70).
Variations in the technique should be based on
One-step/two- or three-paste
the periodontal biotype and the number of missing
tech nique
teeth. In cases where the periodontal tissue is thin
Impression materials are classified in terms of nuid and retraction is thus carefully kept to a minimum,
ity and viscosity, and the latter perform better in the authors avoid using materials with a high vis
reproducing detail. The smallest details are general· cosity in the custom tray, opting instead for a regu-
ly those around the inish line, delineating between lar polyether material (eg, lmpregum Penta Soft) to
the tooth preparation from the i ntact tooth struc· reduce the occlusal force at the gingival sulcus, even �
Figs 9-58 and 9-59 One-step/one- paste technique. The technique uses a medium- or high-viscosity material placed in an
impression tray. When using a high-viscosity material. the only way to obtain a good impression of the intact tooth structure
beyond the finish line is to perform an extensive horizontal retraction of the gingiva. which is not recommended.
Fig g -60 Good clinical result using a medium-viscosity material. which requires less horizontal retraction of the gingiva.
Fig g-61 One-step/two-paste impression technique. The clinician uses high- and low-viscosity polyethers. simultaneously. by
applying the first (light body. low viscosity! in the sulcus and the second (heavy body. high viscosity) in the tray. in the same
plastic state.
Figs 9-62 o 9-4 One-step/two-paste impressions. illustrating the parameters for a precision impression.
Fig 9-65 Polyvinyl siloxane impression (President. Coltine/Whaledentl using the one-step/two-paste technique.
CHAPTER 9
. prostheses. Its popularity probably results from its lure. Low-viscosity materials can be applied in min
simplicity; it uses a single material with one consis imal amounts directly along the finish line. using a
tency at one time (Figs 9·58 to 9-60). Moreover, both syringe equipped with tips suitable for optimal
functions required to obtain a precision impression extrusion and adaptation. Manufacturer kits include
(ie. detail and support) are carried out using only preformed tips with standard-diameter openings (Fig
one material of medium to high consistency (eg, reg 9·66). but these can be replaced by syringe tips with
ular for a polyvinyl siloxane. soft or hard for a poly diferent angles and diameters (Fig 9-67).
ether). Unfortunately, while the support function can When using the single-cord method of retraction.
be performed just as adequately with a medium- or which is their preferred method. the authors choose
regular-viscosity material, the same cannot be said a syringe tip with a very small opening that fits the
for the detail function, which is severely compro minimal space available, both horizontally and ver
mised in the authors' opinion. This technique leads tically (Fig 9-68). During extrusion, they use adapt·
to difficulty in reproducing adequate detail of the able tips for reaching the palatal and lingual sur
finish line preparation without extensive displace faces of the teeth. With suitably curved tips, the
ment of soft tissue. and thus the cervical margins operator can ensure that the impression material
are not always clear and precise. contacts the critical areas to be reproduced in the
The authors firmly prefer the other techniques impression. Tips produced by Anthogyr or Centrix
over this one because they allow for the use of permit the operator to modiy the diameter and
materials of diferent consistencies for each function angle of curvature without creating undesirable bot
(detail or support) i n the same plastic phase. The tlenecks in the extrusion channel. Tips that can be
clinician never allows one of the materials to hard adapted to suit the clinical case and the operator's
en before the other (Figs 9-61 to 9·65). working position allow easy application in areas where
access is otherwise difficult (Figs 9-69 and 9-70).
Variations in the technique should be based on
One-step/two- or three-paste
the periodontal biotype and the number of missing
tech nique
teeth. In cases where the periodontal tissue is thin
Impression materials are classified in terms of nuid and retraction is thus carefully kept to a minimum,
ity and viscosity, and the latter perform better in the authors avoid using materials with a high vis
reproducing detail. The smallest details are general· cosity in the custom tray, opting instead for a regu-
ly those around the inish line, delineating between lar polyether material (eg, lmpregum Penta Soft) to
the tooth preparation from the i ntact tooth struc· reduce the occlusal force at the gingival sulcus, even �
Figs 9-58 and 9-59 One-step/one- paste technique. The technique uses a medium- or high-viscosity material placed in an
impression tray. When using a high-viscosity material. the only way to obtain a good impression of the intact tooth structure
beyond the finish line is to perform an extensive horizontal retraction of the gingiva. which is not recommended.
Fig g -60 Good clinical result using a medium-viscosity material. which requires less horizontal retraction of the gingiva.
Fig g-61 One-step/two-paste impression technique. The clinician uses high- and low-viscosity polyethers. simultaneously. by
applying the first (light body. low viscosity! in the sulcus and the second (heavy body. high viscosity) in the tray. in the same
plastic state.
Figs 9-62 o 9-4 One-step/two-paste impressions. illustrating the parameters for a precision impression.
Fig 9-65 Polyvinyl siloxane impression (President. Coltine/Whaledentl using the one-step/two-paste technique.
CHAPTER 9
FIG 9-66 FIG 9-67 FIG 9-69 FIG 9-70
C O R R E C T R E L AT I O N A M O N G T H E T I P ' S
D I M E N S I O N S A N D H O R I Z O NTA L D E F L E C T I O N
Fig g-66 Syringe and tip used to extrude low- and medium-viscosity materials.
Fig g-67 Comparison of lip included with the Pentamix I I unit (top) and Anthogyr tip (bottom). The smaller-diameter opening of the Anthogyr
tip corresponds more readily to the space of the sulcus.
Figs g-68 and g_6g Different tips can be used. and the shape of the opening can be altered.
Fig g-70 Tip curves also can be customized by the operator to facilitate access i n operating areas.
FIG 9-68
HI
CHAPTER 9
FIG 9-66 FIG 9-67 FIG 9-69 FIG 9-70
C O R R E C T R E L AT I O N A M O N G T H E T I P ' S
D I M E N S I O N S A N D H O R I Z O NTA L D E F L E C T I O N
Fig g-66 Syringe and tip used to extrude low- and medium-viscosity materials.
Fig g-67 Comparison of lip included with the Pentamix I I unit (top) and Anthogyr tip (bottom). The smaller-diameter opening of the Anthogyr
tip corresponds more readily to the space of the sulcus.
Figs g-68 and g_6g Different tips can be used. and the shape of the opening can be altered.
Fig g-70 Tip curves also can be customized by the operator to facilitate access i n operating areas.
FIG 9-68
HI
CHAPTER 9
. in the presence of several teeth and extensive pros material used'-that is, sections of thicker material . In theory this technique is appealing, and con- thickness is suitable for the detail reproduction of a
theses (Fig 9-71). contract more than sections with thinner material. ceptually it provides a method for obtaining a high light-bodied material. Nissan et al46 conducted a
I n complex treatments involving numerous eden Phillips3 underscores the necessity of using less precision impression, free of distortion from con· study using 45 impressions made from a steel cast
tulous areas, the authors use a high-viscosity mate· material by advocating the putty-wash technique, traction. However, impressions made with this tech and roughening the putty for thicknesses of t, 2,
rial (lmpregum Penta) as a support material along which i nvolves taking an i mpression in two stages, nique, while very accurate in reproducing detail, are and 3 mm. Their findings indicate that a thickness
with a low-viscosity material (Permadyne Light Body) separately applying two materials of different vis often distorted (Fig 9-78). of 3 mm is to be avoided because the resulting plas
in a syringe (Figs 9-72 and 9-73). However, if a thin cosity.4J .44 When studied through in vitro tests under con ter casts differed significantly from the original.
biotype is a consideration as well, the clinician can The principle of contraction gave rise to methods trolled conditions and on steel casts or casts de· However, the ideal thickness of 2 m m or less poses
use the three-paste technique, involving the appli that use highly viscous putty as a support material. signed for repeated insertion and removal, the im a significant obstacle to correct reinsertion without
cation of a medium-viscosity material over the detail Once the putty hardens, it works as a support for a pressions are rated as comparable to or better than inadvertently touching the putty.
material (lmpregum Penta Soft) using a syringe. This low-viscosity or light relining material. In this tech those obtained with a single-step technique.44-4S On the interior surface, where only the color of
method reduces the pressure from the high-viscosi nique, a preliminary impression is taken of the Reinsertion, however, is a key problem in this pro the light-bodied material should be visible, the ap
ty material and improves the tear strength of the entire arch using a putty material with a high degree cedure because it is difficult to recenter and refit the pearance of a putty color in several areas indicates
low-viscosity material. In cases where the periodon of hardness. After the hardened putty is removed impression tray perfectly, avoiding contact with the the impression's contact with a material already in
tal tissues are thick, adequate gingival reflection from the mouth, the impression is roughened with hardened putty in order to create a final impression the elastic, and not plastic, stage. This anomalous
may be accomplished without hesitation, and high large laboratory burs or scalpels, then relined with a whose interior surface is entirely identical in color to contact with hardened putty, which is thus unable to
viscosity materials can be used for support after fol low-viscosity impression material. The roughening the low-viscosity material (Figs 9-79 to 9-82). Only adapt to any shape, generates a distortion wave
lowing the application of low-viscosity materials to stage focuses on the interproximal areas, removing when the impression is free of direct tooth contact that originates from a point not necessarily involved
record the sulcus. the septa and the midline of the teeth. By minimiz with the putty is it truly accurate, but all too often in the prosthetic treatment, resulting in an impres
In summary, for all possible combinations low ing the space for the low-viscosity materiai,4S the this technique yields inaccurate and distorted sion with serious defects. For this reason, the authors
viscosity material is used to reproduce detail and clinician reduces the amount of contraction, at least impressions. prefer techniques in which the materials are in the
the paste used i n the tray, regardless of viscosity, in theorya At this point, the clinician reseats the A clinical technique for avoiding tooth-putty con same physical state (plastic), such as the one-step/
is used for support. i mpression tray, which has been relined with low tact on reinsetion involves roughing out the interi two-paste technique. ..
viscosity material. The first impression works like a or as much as possible while ensuring that the
custom tray; it leaves minimal space for the filling

Two-step/two-paste technique
material, but is highly precise, and functions to sup
( putty wash)
port the light material as it reproduces details of the
During polymerization and hardening, impression ma finish line (Figs 9-74 to 9-77). _
terials shrink in direct proportion to the quantity of
2
CHAPTER 9
. in the presence of several teeth and extensive pros material used'-that is, sections of thicker material . In theory this technique is appealing, and con- thickness is suitable for the detail reproduction of a
theses (Fig 9-71). contract more than sections with thinner material. ceptually it provides a method for obtaining a high light-bodied material. Nissan et al46 conducted a
I n complex treatments involving numerous eden Phillips3 underscores the necessity of using less precision impression, free of distortion from con· study using 45 impressions made from a steel cast
tulous areas, the authors use a high-viscosity mate· material by advocating the putty-wash technique, traction. However, impressions made with this tech and roughening the putty for thicknesses of t, 2,
rial (lmpregum Penta) as a support material along which i nvolves taking an i mpression in two stages, nique, while very accurate in reproducing detail, are and 3 mm. Their findings indicate that a thickness
with a low-viscosity material (Permadyne Light Body) separately applying two materials of different vis often distorted (Fig 9-78). of 3 mm is to be avoided because the resulting plas
in a syringe (Figs 9-72 and 9-73). However, if a thin cosity.4J .44 When studied through in vitro tests under con ter casts differed significantly from the original.
biotype is a consideration as well, the clinician can The principle of contraction gave rise to methods trolled conditions and on steel casts or casts de· However, the ideal thickness of 2 m m or less poses
use the three-paste technique, involving the appli that use highly viscous putty as a support material. signed for repeated insertion and removal, the im a significant obstacle to correct reinsertion without
cation of a medium-viscosity material over the detail Once the putty hardens, it works as a support for a pressions are rated as comparable to or better than inadvertently touching the putty.
material (lmpregum Penta Soft) using a syringe. This low-viscosity or light relining material. In this tech those obtained with a single-step technique.44-4S On the interior surface, where only the color of
method reduces the pressure from the high-viscosi nique, a preliminary impression is taken of the Reinsertion, however, is a key problem in this pro the light-bodied material should be visible, the ap
ty material and improves the tear strength of the entire arch using a putty material with a high degree cedure because it is difficult to recenter and refit the pearance of a putty color in several areas indicates
low-viscosity material. In cases where the periodon of hardness. After the hardened putty is removed impression tray perfectly, avoiding contact with the the impression's contact with a material already in
tal tissues are thick, adequate gingival reflection from the mouth, the impression is roughened with hardened putty in order to create a final impression the elastic, and not plastic, stage. This anomalous
may be accomplished without hesitation, and high large laboratory burs or scalpels, then relined with a whose interior surface is entirely identical in color to contact with hardened putty, which is thus unable to
viscosity materials can be used for support after fol low-viscosity impression material. The roughening the low-viscosity material (Figs 9-79 to 9-82). Only adapt to any shape, generates a distortion wave
lowing the application of low-viscosity materials to stage focuses on the interproximal areas, removing when the impression is free of direct tooth contact that originates from a point not necessarily involved
record the sulcus. the septa and the midline of the teeth. By minimiz with the putty is it truly accurate, but all too often in the prosthetic treatment, resulting in an impres
In summary, for all possible combinations low ing the space for the low-viscosity materiai,4S the this technique yields inaccurate and distorted sion with serious defects. For this reason, the authors
viscosity material is used to reproduce detail and clinician reduces the amount of contraction, at least impressions. prefer techniques in which the materials are in the
the paste used i n the tray, regardless of viscosity, in theorya At this point, the clinician reseats the A clinical technique for avoiding tooth-putty con same physical state (plastic), such as the one-step/
is used for support. i mpression tray, which has been relined with low tact on reinsetion involves roughing out the interi two-paste technique. ..
viscosity material. The first impression works like a or as much as possible while ensuring that the
custom tray; it leaves minimal space for the filling

Two-step/two-paste technique
material, but is highly precise, and functions to sup
( putty wash)
port the light material as it reproduces details of the
During polymerization and hardening, impression ma finish line (Figs 9-74 to 9-77). _
terials shrink in direct proportion to the quantity of
2
9-BO
9-8 2
Fig g-78 Impression made using the putty-wash technique. The presence of the yellow putty. which had already hardened at the time of rein
Fig g-71 1mpression o_f a maxilla 'y restoration using medium-viscosity polyether support material and low-viscosity polyether detail materi
. sertion with the green impression material. clearly indicates areas of compression. Therefore. when two colors are seen. the effect is similar
al. The thon ompressoon of the on tact tooth structure beyond the finish line is a common feature of thin periodontal biotypes. Figs g -12 and
9-73 1mpression made with a medium-viscosity support material and a low-viscosity detail material for a complex restoration. The finish line to a metal tray coming into contact with an incisal edge. Distortion is usually masked by the elasticity of the silicone. but it is nevertheless
present and can resull in a restoration wilh undesired friction and poor marginal fit. Fig 9-79 Sagittal cross section of a cast impression.
is cle � rly visible _aro_und the circumferenc_e of each toot � . Fig 9-7� Irreversible hydrocolloid impression of a healthy dentition. An area of com
pressoon _ on the oncosal edge of the maxollary central onCISors (due to excessive pressure during insertion and application in the mouth) Properly centering an impression tray is difficult when the materials are in the same plastic state: it is even more difficult with the thinly
spread relonong materoal of the putty-wash technoque. Fog 9-80 In reducong the forst putty ompressoon. _ too much material was removed. lead
resulted on contact between the metalloc tray and the oncosal edge. Fig g -75 The impression for this cast appeared accurate to the naked eye.
ing to an excess of _low-viscosity reliner. Figs g -81 and g -82 Cross se � tions of two different teeth from the same impression. Medium-intensity
but once it was invested with plaster the incisal defect became evident. Figs 9-76 and 9-77 Comparison of healthy dentition and the working g
putty compressoon IS evodent on Fog - 8 1 . but severe compressoon IS evodent on the premolar preparatoon of Fig 9-82. A longitudinal cross
cast developed from the faulty impression. Severe deformation caused by an area of compression occurs when an impression is taken with
section permits the evaluation of the common distortions and alterations of the different impression materials and techniques.
a rigid support (custom tray or prehardened putty) and contact is erroneously made between the support and the tooth to be restored.
9-BO
9-8 2
Fig g-78 Impression made using the putty-wash technique. The presence of the yellow putty. which had already hardened at the time of rein
Fig g-71 1mpression o_f a maxilla 'y restoration using medium-viscosity polyether support material and low-viscosity polyether detail materi
. sertion with the green impression material. clearly indicates areas of compression. Therefore. when two colors are seen. the effect is similar
al. The thon ompressoon of the on tact tooth structure beyond the finish line is a common feature of thin periodontal biotypes. Figs g -12 and
9-73 1mpression made with a medium-viscosity support material and a low-viscosity detail material for a complex restoration. The finish line to a metal tray coming into contact with an incisal edge. Distortion is usually masked by the elasticity of the silicone. but it is nevertheless
present and can resull in a restoration wilh undesired friction and poor marginal fit. Fig 9-79 Sagittal cross section of a cast impression.
is cle � rly visible _aro_und the circumferenc_e of each toot � . Fig 9-7� Irreversible hydrocolloid impression of a healthy dentition. An area of com
pressoon _ on the oncosal edge of the maxollary central onCISors (due to excessive pressure during insertion and application in the mouth) Properly centering an impression tray is difficult when the materials are in the same plastic state: it is even more difficult with the thinly
spread relonong materoal of the putty-wash technoque. Fog 9-80 In reducong the forst putty ompressoon. _ too much material was removed. lead
resulted on contact between the metalloc tray and the oncosal edge. Fig g -75 The impression for this cast appeared accurate to the naked eye.
ing to an excess of _low-viscosity reliner. Figs g -81 and g -82 Cross se � tions of two different teeth from the same impression. Medium-intensity
but once it was invested with plaster the incisal defect became evident. Figs 9-76 and 9-77 Comparison of healthy dentition and the working g
putty compressoon IS evodent on Fog - 8 1 . but severe compressoon IS evodent on the premolar preparatoon of Fig 9-82. A longitudinal cross
cast developed from the faulty impression. Severe deformation caused by an area of compression occurs when an impression is taken with
section permits the evaluation of the common distortions and alterations of the different impression materials and techniques.
a rigid support (custom tray or prehardened putty) and contact is erroneously made between the support and the tooth to be restored.
CHAPTER 9
. FAI LU R ES A N D T H E I R P R I N C I PAL I rregular material in the fin ish line

area
B ETTER R E S U LTS U S I N G MATE R I A L S I N SA M E P H YS I CA L STATE
CAUSES
Failures that occur while taking an impression are • Lack of polymerization resulting from the pres
caused by factors related to human error-either ence of blood or incompatible hemostatic or
aulty operational decision making or inadequate eval astringent substances (Fig 9-90)
uation of objectives. In addition, complications unan
ticipated by tests performed under in vitro conditions
Rough or powdery plaster cast
may arise in clinical situations that are far from ideal.
• Inadequate cleaning of the impression
• Excess water left on the surface of the impression
Rough and irregular i m pression surface
• Excess tensioactive substance let on the impression
• Incomplete polymerization resulting from premature • Premature removal of the cast
removal from the mouth, incorrect ratios or incorrect • Incorrect manipulation of the plaster
mixing of the components, or the presence of oily Premature investment of the i mpression before
substances or organic material on the teeth the minimum time elapsed
• During mechanical mixing, the two components
(base paste and catalyst) were not added simul
Distortion
taneously
• Rapid polymerization resulting from excessive • Resin impression tray inadequately hardened and
humidity or high temperatures still subject to polymerization contraction
• Catalyst-base ratio too high for condensation sil • Poor adhesion of the elastomer to the tray caused
icones by an insufficient adhesive layer, premature filling
• Surface interference from polyethers with bond of the tray after adhesive application, or use of
ing substances not daubed with alcohol or from an unsuitable adhesive
non polymerization of the resin composite due to • Loss of mechanical retention for the materials un
lack of oxygen afected by the adhesive
• Elastic properties of the impression material devel
oped before insertion of the tray'
Air bubbles
• Use of excessive amount of material
• Excessively rapid polymerization impeding the • Excessive or insuficient space created for the low
low of the material viscosity material during the putty-wash technique
• Incorporation of air in the mechanical or manual • Continuous pressure on an impression material
mixing process that has already developed elastic properties
• Incorrect filling of the tray (Figs 9-83 and 9-84) • Movement of the tray during the polymerization
stage
Fig 9-83 Small air bubble near the cervical margin. Air bubbles cannot always be prevented. but because it is outside of tho
• Delay in casting from polysulfide or condensation restoration area. this one will not influence the subsequent procedures or compromise the impression. Fig 9-4 Small bubble
I rregular-shaped holes on the surface of the tooth due to a tooth preparation defect. When the cast is poured. the tooth preparation will have an air
silicone impressions bubble. which tho technician can eliminate easily without jeopardizing the restoration.
• Moisture or detritus on the surface of the teeth • Premature removal from the mouth or removal
• Poor adaptation of the material to the surface of with improper movement (eg, removal from only
the tooth (Figs 9-85 to 9-89) one side) (Figs 9-91 to 9-93) .
fi f7
CHAPTER 9
. FAI LU R ES A N D T H E I R P R I N C I PAL I rregular material in the fin ish line

area
B ETTER R E S U LTS U S I N G MATE R I A L S I N SA M E P H YS I CA L STATE
CAUSES
Failures that occur while taking an impression are • Lack of polymerization resulting from the pres
caused by factors related to human error-either ence of blood or incompatible hemostatic or
aulty operational decision making or inadequate eval astringent substances (Fig 9-90)
uation of objectives. In addition, complications unan
ticipated by tests performed under in vitro conditions
Rough or powdery plaster cast
may arise in clinical situations that are far from ideal.
• Inadequate cleaning of the impression
• Excess water left on the surface of the impression
Rough and irregular i m pression surface
• Excess tensioactive substance let on the impression
• Incomplete polymerization resulting from premature • Premature removal of the cast
removal from the mouth, incorrect ratios or incorrect • Incorrect manipulation of the plaster
mixing of the components, or the presence of oily Premature investment of the i mpression before
substances or organic material on the teeth the minimum time elapsed
• During mechanical mixing, the two components
(base paste and catalyst) were not added simul
Distortion
taneously
• Rapid polymerization resulting from excessive • Resin impression tray inadequately hardened and
humidity or high temperatures still subject to polymerization contraction
• Catalyst-base ratio too high for condensation sil • Poor adhesion of the elastomer to the tray caused
icones by an insufficient adhesive layer, premature filling
• Surface interference from polyethers with bond of the tray after adhesive application, or use of
ing substances not daubed with alcohol or from an unsuitable adhesive
non polymerization of the resin composite due to • Loss of mechanical retention for the materials un
lack of oxygen afected by the adhesive
• Elastic properties of the impression material devel
oped before insertion of the tray'
Air bubbles
• Use of excessive amount of material
• Excessively rapid polymerization impeding the • Excessive or insuficient space created for the low
low of the material viscosity material during the putty-wash technique
• Incorporation of air in the mechanical or manual • Continuous pressure on an impression material
mixing process that has already developed elastic properties
• Incorrect filling of the tray (Figs 9-83 and 9-84) • Movement of the tray during the polymerization
stage
Fig 9-83 Small air bubble near the cervical margin. Air bubbles cannot always be prevented. but because it is outside of tho
• Delay in casting from polysulfide or condensation restoration area. this one will not influence the subsequent procedures or compromise the impression. Fig 9-4 Small bubble
I rregular-shaped holes on the surface of the tooth due to a tooth preparation defect. When the cast is poured. the tooth preparation will have an air
silicone impressions bubble. which tho technician can eliminate easily without jeopardizing the restoration.
• Moisture or detritus on the surface of the teeth • Premature removal from the mouth or removal
• Poor adaptation of the material to the surface of with improper movement (eg, removal from only
the tooth (Figs 9-85 to 9-89) one side) (Figs 9-91 to 9-93) .
fi f7
FIG 9-90 FIG 9·91
D I STORT I O N : T H E P R I N C I PAL E N E M Y O F T H E P R O S T H E S I S
FIG 9-85
FIG 9-86 FIG 9-87
FIG 9-92 FIG 9-93
Fig g .as Defect involving the finish line. While the defects in the two preVIous examples d1d not hinder further work. this impression must be retaken.
The impression should be exammed under a microscope to avo1d sending the laboratory Impressions that cannot be used and requiring an additional
appointment with the patient to take impressions. Figs 9-86 to 9-89 Two different impressions of the same teeth. both cast in epoxy res1n. Figs 9-86 and
g.a7 The cervical limits and detail of the finish line are correct. but the impression has not adapted properly on the buccal aspect. The cast from this
impression highlights the area of distortion. Figs g .aa and g .ag A second impression was retaken during the same appointment because the defect was
noticed immediately. The clinician may have difficulty knowing the degree of imperfection 1n an impression. F1g g. go Occasionally. a portion of retrac
tion cord can become trapped in the impression. Magnification should be used to check whether the cord would compromise a cast of the intact tooth
FIG 9-88 FIG 9-89 structure apical to the finish tine. In this case. the cord does not alter the situation significantly. so the impression can be sent to the laboratory as
is. and the cord will be removed only after casting. F1gs g .g 1 and g . gz Polyvinyl s1loxane impression with stretched areas and bubbles at the prepara
tion margin. The cast shows serious defects i n both the tooth preparation and the impression: work cannot be continued. Fig 9-93 Cross section of a
cast impression and impression tray to evaluate the spacing and the centenng of the custom tray Impression Because the tray was badly centered in
the patient's mouth and came into contact with the shoulder of a tooth. It would have beon clinically useless
FIG 9-90 FIG 9·91
D I STORT I O N : T H E P R I N C I PAL E N E M Y O F T H E P R O S T H E S I S
FIG 9-85
FIG 9-86 FIG 9-87
FIG 9-92 FIG 9-93
Fig g .as Defect involving the finish line. While the defects in the two preVIous examples d1d not hinder further work. this impression must be retaken.
The impression should be exammed under a microscope to avo1d sending the laboratory Impressions that cannot be used and requiring an additional
appointment with the patient to take impressions. Figs 9-86 to 9-89 Two different impressions of the same teeth. both cast in epoxy res1n. Figs 9-86 and
g.a7 The cervical limits and detail of the finish line are correct. but the impression has not adapted properly on the buccal aspect. The cast from this
impression highlights the area of distortion. Figs g .aa and g .ag A second impression was retaken during the same appointment because the defect was
noticed immediately. The clinician may have difficulty knowing the degree of imperfection 1n an impression. F1g g. go Occasionally. a portion of retrac
tion cord can become trapped in the impression. Magnification should be used to check whether the cord would compromise a cast of the intact tooth
FIG 9-88 FIG 9-89 structure apical to the finish tine. In this case. the cord does not alter the situation significantly. so the impression can be sent to the laboratory as
is. and the cord will be removed only after casting. F1gs g .g 1 and g . gz Polyvinyl s1loxane impression with stretched areas and bubbles at the prepara
tion margin. The cast shows serious defects i n both the tooth preparation and the impression: work cannot be continued. Fig 9-93 Cross section of a
cast impression and impression tray to evaluate the spacing and the centenng of the custom tray Impression Because the tray was badly centered in
the patient's mouth and came into contact with the shoulder of a tooth. It would have beon clinically useless
CHAPTER 9
� I M PRESS I O N S FOR I M PLANT and even plaster) and requires many techniques (eg, � and finish the prosthetic work on the master cast, ments are screwed on the implant, the screw holes
S U P P O RTED RESTORAT I O N S various ways of splinting). The literature is replete preferably in a single-casting monoblock. are protected with moist cotton swabs to prevent
with in vitro studies that underscore the inadequate Otherwise, the clinician must take an initial im the plaster from closing up the holes. and the tray
Impression materials are t h e only solution for gath· results obtained using medium- and high-viscosity pression using the conventional pickup technique is filled with extra-hard, q uick-drying plaster (Snow
ering necessary clinical information to construct elastomers, 59 and others where the gap left after and then seat the abutments on the implants in par White, Kerr Hawe) using a syringe with a cut tip. The
functional and esthetic restorations. taking an impression with polyethers averages 190 allel in the laboratory, using a bur and a parallel plaster is allowed to harden completely, and care is
The advent of implant dentistry and the develop �m 6o The lack of consistent results creates error ometer. taken to remove the excess material onto the sur
ment of prosthetic implant techniques. which in and false expectations for the clinical operator; face of the small mold, onto which an adhesive suit
volve the study and analysis of the passive fit, have there is no doubt that an elastomer impression of able for elastomers will be applied (Fig 9-100).
Modular custom i m p ression tray
called into question the validity and accuracy of several i mplants, i f executed in the traditional man After the most apical area of the first tray is filled
i mpression materials. Giordano underscored the ner, will not yield reliable results. When taking an impression of mixed dentition, with an elastomer extruded through a syringe, the
limitations of impression materials in stating that Suppoted by findings in the literature,6• the including natural teeth and implants, a modular second tray is illed with the impression material
implant-supported restorations require extreme authors are convinced that the only way to avoid impression tray, composed of a small open mold on and centered precisely over the tray holding the
accuracy; small impressions are acceptable for fixed error during transfer of the implant position is to the top that serves to support the plaster, can be hardened plaster. When the elastomer has hard
prostheses because of the movement permitted by use plaster as an impression material or to splint used. The custom tray holds the small mold and is ened, the blocking screws anchoring the transfer
the periodontal ligament, but this luxury does not the elements being transferred.6' Plaster is the cut away to permit the unscrewing of the transfer copings are removed, and the entire system is
exist when using implants.•' impression material of choice for achieving an exact copings. This custom tray (with a cutaway area for extracted from the mouth, thus making a precision
The techniques of impression taking for an reproduction of the implant position, and in the case the implants) fits the entire arch and is used to take impression that includes both the position of the
implant-supported restoration have changed over of edentulous patients, who must undergo a full an impression of the residual teeth in elastomeric implants and their relationship to the adjacent teeth
time. Methods of implant positioning in the labora· mouth rehabilitation with implants, this can be material. (Fig 9· 101).
tory have evolved from a direct technique, to accomplished using a plastic impression tray or a To make a modular custom impression tray, the The dental technician will then make a single cast
removal and subsequent reinsertion of the transfer custom tray created specifically for the purpose. The clinician must have a cast that represents the on the abutments, which will be made to provide a
coping, to the latest procedure known as the pick dental technician will destroy the tray to remove the implant site, indicated by the healing abutments or passive fit with the implants directly in the lab.
up technique.•;' These techniques use traditional plaster impression and pour a cast using other den· a diagnostic cast. The implant site is delimited with Therefore, no paste is needed to detect tension or
impression materials (generally elastomers) with tal stone that is properly isolated with a layer of a block of sot wax or by a small mold of the same distortion directly i n the mouth.
custom trays that are cut out where the implant insulating material. resin, so that it occupies the part that will later be The accuracy of this i mpression technique is illus
emerges, allowing the removal of the anchor screw The clinical procedure becomes more complicat- filled with plaster. The example shows a clinical case trated clinically in a case of multiple implants i n the
before the hardened impression material is removed ed when implants are present in a mixed dentition, in which the analogue (ie, a cast produced from an posterior dentition. In a 63·year-old female patient,
from the oral cavity (Fig 9-94). Scientific studies of including healthy natural teeth and teeth prepared impression with the transfer coping using the pick two implants were placed in the mandibular left
impression techniques have found that when work for a prosthesis. For this reason, the authors have up technique) is already inserted in the plaster. quadrant and three in the mandibular right quad
ing on a single element, the pickup technique with designed a modular system of custom impression Around this block, a small, well-adapted mold of rant. The patient authorized the taking of three
subsequent repositioning in the i mpression for the trays, which are made directly in the clinician's self-curing resin (MultiTray) is left open occlusally. It impressions with custom trays, two modular and
casting is preferable to the cut-away procedure, office. This system results in a one-step impression is polymerized in the light-curing unit (Multilight) for one using the conventional pickup technique. The
though it tends to result in rotational errors.53 made of plaster for the i m plants and of polyether or 5 minutes (Figs 9-95 and 9-96). abutments were prepared di rectly on one of the
Over the years, in vitro and survey studiess•-ss of polyvinyl siloxane for the remaining dentition. I f the The custom tray is made by applying a sheet of two plaster-elastomer casts, shaping and casting a
prosthetic fit have demonstrated that definitive clinician uses parallel implants or implants without wax, with a thickness calibrated for the elastomer, to mono block structure in noble metal alloy on the two
restorations are neither precise nor passive. an internal hexagon or connections that impede the the resin mold, following the procedure already lateral segments. The framework thus obtained can
Impression taking with implants involves the use of removal of the transfer coping, it is possible to described for making a custom impression tray (Figs be fit to the cast to verify the implant position ob
different materials (eg, high-viscosity elastomers obtain their exact position i n a single impression .. 9-97 to 9-99). After the transfer copings or abut- tained from the three diferent impressions, two in ..
301
CHAPTER 9
� I M PRESS I O N S FOR I M PLANT and even plaster) and requires many techniques (eg, � and finish the prosthetic work on the master cast, ments are screwed on the implant, the screw holes
S U P P O RTED RESTORAT I O N S various ways of splinting). The literature is replete preferably in a single-casting monoblock. are protected with moist cotton swabs to prevent
with in vitro studies that underscore the inadequate Otherwise, the clinician must take an initial im the plaster from closing up the holes. and the tray
Impression materials are t h e only solution for gath· results obtained using medium- and high-viscosity pression using the conventional pickup technique is filled with extra-hard, q uick-drying plaster (Snow
ering necessary clinical information to construct elastomers, 59 and others where the gap left after and then seat the abutments on the implants in par White, Kerr Hawe) using a syringe with a cut tip. The
functional and esthetic restorations. taking an impression with polyethers averages 190 allel in the laboratory, using a bur and a parallel plaster is allowed to harden completely, and care is
The advent of implant dentistry and the develop �m 6o The lack of consistent results creates error ometer. taken to remove the excess material onto the sur
ment of prosthetic implant techniques. which in and false expectations for the clinical operator; face of the small mold, onto which an adhesive suit
volve the study and analysis of the passive fit, have there is no doubt that an elastomer impression of able for elastomers will be applied (Fig 9-100).
Modular custom i m p ression tray
called into question the validity and accuracy of several i mplants, i f executed in the traditional man After the most apical area of the first tray is filled
i mpression materials. Giordano underscored the ner, will not yield reliable results. When taking an impression of mixed dentition, with an elastomer extruded through a syringe, the
limitations of impression materials in stating that Suppoted by findings in the literature,6• the including natural teeth and implants, a modular second tray is illed with the impression material
implant-supported restorations require extreme authors are convinced that the only way to avoid impression tray, composed of a small open mold on and centered precisely over the tray holding the
accuracy; small impressions are acceptable for fixed error during transfer of the implant position is to the top that serves to support the plaster, can be hardened plaster. When the elastomer has hard
prostheses because of the movement permitted by use plaster as an impression material or to splint used. The custom tray holds the small mold and is ened, the blocking screws anchoring the transfer
the periodontal ligament, but this luxury does not the elements being transferred.6' Plaster is the cut away to permit the unscrewing of the transfer copings are removed, and the entire system is
exist when using implants.•' impression material of choice for achieving an exact copings. This custom tray (with a cutaway area for extracted from the mouth, thus making a precision
The techniques of impression taking for an reproduction of the implant position, and in the case the implants) fits the entire arch and is used to take impression that includes both the position of the
implant-supported restoration have changed over of edentulous patients, who must undergo a full an impression of the residual teeth in elastomeric implants and their relationship to the adjacent teeth
time. Methods of implant positioning in the labora· mouth rehabilitation with implants, this can be material. (Fig 9· 101).
tory have evolved from a direct technique, to accomplished using a plastic impression tray or a To make a modular custom impression tray, the The dental technician will then make a single cast
removal and subsequent reinsertion of the transfer custom tray created specifically for the purpose. The clinician must have a cast that represents the on the abutments, which will be made to provide a
coping, to the latest procedure known as the pick dental technician will destroy the tray to remove the implant site, indicated by the healing abutments or passive fit with the implants directly in the lab.
up technique.•;' These techniques use traditional plaster impression and pour a cast using other den· a diagnostic cast. The implant site is delimited with Therefore, no paste is needed to detect tension or
impression materials (generally elastomers) with tal stone that is properly isolated with a layer of a block of sot wax or by a small mold of the same distortion directly i n the mouth.
custom trays that are cut out where the implant insulating material. resin, so that it occupies the part that will later be The accuracy of this i mpression technique is illus
emerges, allowing the removal of the anchor screw The clinical procedure becomes more complicat- filled with plaster. The example shows a clinical case trated clinically in a case of multiple implants i n the
before the hardened impression material is removed ed when implants are present in a mixed dentition, in which the analogue (ie, a cast produced from an posterior dentition. In a 63·year-old female patient,
from the oral cavity (Fig 9-94). Scientific studies of including healthy natural teeth and teeth prepared impression with the transfer coping using the pick two implants were placed in the mandibular left
impression techniques have found that when work for a prosthesis. For this reason, the authors have up technique) is already inserted in the plaster. quadrant and three in the mandibular right quad
ing on a single element, the pickup technique with designed a modular system of custom impression Around this block, a small, well-adapted mold of rant. The patient authorized the taking of three
subsequent repositioning in the i mpression for the trays, which are made directly in the clinician's self-curing resin (MultiTray) is left open occlusally. It impressions with custom trays, two modular and
casting is preferable to the cut-away procedure, office. This system results in a one-step impression is polymerized in the light-curing unit (Multilight) for one using the conventional pickup technique. The
though it tends to result in rotational errors.53 made of plaster for the i m plants and of polyether or 5 minutes (Figs 9-95 and 9-96). abutments were prepared di rectly on one of the
Over the years, in vitro and survey studiess•-ss of polyvinyl siloxane for the remaining dentition. I f the The custom tray is made by applying a sheet of two plaster-elastomer casts, shaping and casting a
prosthetic fit have demonstrated that definitive clinician uses parallel implants or implants without wax, with a thickness calibrated for the elastomer, to mono block structure in noble metal alloy on the two
restorations are neither precise nor passive. an internal hexagon or connections that impede the the resin mold, following the procedure already lateral segments. The framework thus obtained can
Impression taking with implants involves the use of removal of the transfer coping, it is possible to described for making a custom impression tray (Figs be fit to the cast to verify the implant position ob
different materials (eg, high-viscosity elastomers obtain their exact position i n a single impression .. 9-97 to 9-99). After the transfer copings or abut- tained from the three diferent impressions, two in ..
301
CHAPTER 9
� plaster-polyether and one in complete polyether. ament, which compensates, in part, for a minimal
The abutments are screwed on the analogues on degree of imperfection and permits the seating of
each of the three casts to check the adaptation of the fixed dental restorations.
the single cast. The authors' working philosophy demands that
The key aspect is the repeatability of the mixed during tooth preparation for a conventional pros
plaster-€1astomer i mpression: the structures adapt thesis, the clinician must think not only about seat
perfectly to the positions on these casts, while those ing the restoration, but above all of eliminating,
made in all elastomer result in considerable gaps through close adherence to the recommended pro
and poor adaptation (igs 9-102 to 9-105). This aspect cedures, all possible sources of tension on the
further recommends the use of plaster for implant i mpression materials (Figs 9-106 to 9-108). During
impressions. The nonrepeatability of elastomeric im preparation, the clinician must act in accordance
pressions, true for both implants and natural denti with the characteristics of the impression materials,
tion, proves that though these materials have accu even before considering the aspects related to the
rate results for in vitro studies, the stress they are type of prosthesis and the material used for making
subjected to in clinical settings often exceeds the it. Given the characteristics of the impression mate
elastic limit of the material. Precise prosthetic restor rials available today, this is the means by which the
ations that adapt well to the natural dentition are clinician may achieve maximum precision (Figs 9-109
closely linked to the presence of the periodontal lig- to 9-134). •
Fig 9-94 Pickup technique for making impressions for implant-supported prostheses. This type of impression yields unpre
dictable results in clinical treatment. Fig 9-95 Fabrication of a modular custom impression tray. There are two modules. one
for taking a plaster impression of the implant area and the other for taking an elastomeric impression of the remai ning den
tition. The plaster module is made by either adapting a strip of curing resin around a block of wax or directly shaping the
resin and positioning it around the implant site to contain the plaster. Figs g_g6 and 9-g7 Spacing wax covers the cast and the
mold for the plaster. Wax has been removed in areas to make occlusal stops for centering the impression. Figs g -98 and 9-99
Finished modular custom impression tray.
02 3
CHAPTER 9
� plaster-polyether and one in complete polyether. ament, which compensates, in part, for a minimal
The abutments are screwed on the analogues on degree of imperfection and permits the seating of
each of the three casts to check the adaptation of the fixed dental restorations.
the single cast. The authors' working philosophy demands that
The key aspect is the repeatability of the mixed during tooth preparation for a conventional pros
plaster-€1astomer i mpression: the structures adapt thesis, the clinician must think not only about seat
perfectly to the positions on these casts, while those ing the restoration, but above all of eliminating,
made in all elastomer result in considerable gaps through close adherence to the recommended pro
and poor adaptation (igs 9-102 to 9-105). This aspect cedures, all possible sources of tension on the
further recommends the use of plaster for implant i mpression materials (Figs 9-106 to 9-108). During
impressions. The nonrepeatability of elastomeric im preparation, the clinician must act in accordance
pressions, true for both implants and natural denti with the characteristics of the impression materials,
tion, proves that though these materials have accu even before considering the aspects related to the
rate results for in vitro studies, the stress they are type of prosthesis and the material used for making
subjected to in clinical settings often exceeds the it. Given the characteristics of the impression mate
elastic limit of the material. Precise prosthetic restor rials available today, this is the means by which the
ations that adapt well to the natural dentition are clinician may achieve maximum precision (Figs 9-109
closely linked to the presence of the periodontal lig- to 9-134). •
Fig 9-94 Pickup technique for making impressions for implant-supported prostheses. This type of impression yields unpre
dictable results in clinical treatment. Fig 9-95 Fabrication of a modular custom impression tray. There are two modules. one
for taking a plaster impression of the implant area and the other for taking an elastomeric impression of the remai ning den
tition. The plaster module is made by either adapting a strip of curing resin around a block of wax or directly shaping the
resin and positioning it around the implant site to contain the plaster. Figs g_g6 and 9-g7 Spacing wax covers the cast and the
mold for the plaster. Wax has been removed in areas to make occlusal stops for centering the impression. Figs g -98 and 9-99
Finished modular custom impression tray.
02 3
CHAPHR 9
Custom Impression Trays a n d Impression Materials
--
s ,.,J � ,
Figs 9-100 and 9-101 In vitro example. The clinician takes a plaster impression (Snow Whitel of the transfer coping screwed onto the Fig g-106 Correct impression yields a distinct and unbroken finish line for the entire perimeter of the tooth. Fig 9-107 Same type of impression
implants. After the plaster hardens in the patient"s mouth. excess material is removed. adhesive is applied to the exteri or of the plaster details obtained with minimal horizontal retraction. This type of impression ensures the long-term stability of the gingiva. Fig g -108 Adequate
_ conta�ns
mold. and elaslomeric material is sealed i n the rest of the dental arch in the custom tray. I n this manner. a s1ngle 1mpress1on _ both
impression requiring improved tooth preparation for the primary reduction and the finishing. The impression material must establish more
modules. as seen in Fig 9 - 1 0 1 . Fig g-102 Three impressions were taken of two areas (the mandibular right and left quadrants! to be restored than just the restorations insertion axis. Fig g. Jog Clinical case of a 64-year-old female patient who presented with serious periodontal
with implant-supported fixed prostheses. The impressions were taken using three series of transfer copin � s. one 1n onl y elastomenc problems and only five Ieeth in the maxillary arch. The teeth will be restored with a telescopic prosthesis after suitable periodontal treat
_
material and the other two in a combination of plaster and elastomer. according to the modular custom impress1on tray technique. Fig 9-103 ment.
Fixed partial denture in a single casting. realized using the first cast from the plaster and polyether impression. Fig g -104 Abutments re
moved and positioned on the cast of the elastomer impression. illustrating the framework"s lack of fit. Fig 9-105 Abutments removed and
positioned on the second plaster-elastomer cast. illustrating the correspondence and good fit. The abutments can b e perfectly supenm
posed on the first plaster-elastomer model. This underscores the clinical repeatability of plaster impressions.
l4
CHAPHR 9
Custom Impression Trays a n d Impression Materials
--
s ,.,J � ,
Figs 9-100 and 9-101 In vitro example. The clinician takes a plaster impression (Snow Whitel of the transfer coping screwed onto the Fig g-106 Correct impression yields a distinct and unbroken finish line for the entire perimeter of the tooth. Fig 9-107 Same type of impression
implants. After the plaster hardens in the patient"s mouth. excess material is removed. adhesive is applied to the exteri or of the plaster details obtained with minimal horizontal retraction. This type of impression ensures the long-term stability of the gingiva. Fig g -108 Adequate
_ conta�ns
mold. and elaslomeric material is sealed i n the rest of the dental arch in the custom tray. I n this manner. a s1ngle 1mpress1on _ both
impression requiring improved tooth preparation for the primary reduction and the finishing. The impression material must establish more
modules. as seen in Fig 9 - 1 0 1 . Fig g-102 Three impressions were taken of two areas (the mandibular right and left quadrants! to be restored than just the restorations insertion axis. Fig g. Jog Clinical case of a 64-year-old female patient who presented with serious periodontal
with implant-supported fixed prostheses. The impressions were taken using three series of transfer copin � s. one 1n onl y elastomenc problems and only five Ieeth in the maxillary arch. The teeth will be restored with a telescopic prosthesis after suitable periodontal treat
_
material and the other two in a combination of plaster and elastomer. according to the modular custom impress1on tray technique. Fig 9-103 ment.
Fixed partial denture in a single casting. realized using the first cast from the plaster and polyether impression. Fig g -104 Abutments re
moved and positioned on the cast of the elastomer impression. illustrating the framework"s lack of fit. Fig 9-105 Abutments removed and
positioned on the second plaster-elastomer cast. illustrating the correspondence and good fit. The abutments can b e perfectly supenm
posed on the first plaster-elastomer model. This underscores the clinical repeatability of plaster impressions.
l4
Custom I mpression Trays a n d ImpresSIOn Materia �
Fig 9-110 ln1t1al stage of treatment. immed�ately follow1ng resectiYe surgery and reconstruction of the missing teeth with fiberglass dowels. Fig 9-112 Finish line repoSitioning and finishing of the tooth preparation
Fig 9-1 1 1 After proper periodontal treatment. the smallest poss1ble retraction cord was posit1oned to vertically retract the gingiva. Figs 9-113 and g -114 Following the use of oscillating instruments and manual rounded chisels. the tooth preparat1ons are well polished. and
the finish line is properly positioned.
01
Custom I mpression Trays a n d ImpresSIOn Materia �
Fig 9-110 ln1t1al stage of treatment. immed�ately follow1ng resectiYe surgery and reconstruction of the missing teeth with fiberglass dowels. Fig 9-112 Finish line repoSitioning and finishing of the tooth preparation
Fig 9-1 1 1 After proper periodontal treatment. the smallest poss1ble retraction cord was posit1oned to vertically retract the gingiva. Figs 9-113 and g -114 Following the use of oscillating instruments and manual rounded chisels. the tooth preparat1ons are well polished. and
the finish line is properly positioned.
01
CHAPTER 9
Figs g-115 o g-111 Higher magnification shows the finish line position. which will be juxlagingival after repositioning. Figs g -118 to g-120 Lateral and occlusal views demonstrate the good parallelism of the preparations and the care taken to avoid injury to the gin
giva.
Figs g-121 and g-122 Elastomeric impression. Because the compression area is on the mucosal tissue and not on the teeth. the impression can
be used.
CHAPTER 9
Figs g-115 o g-111 Higher magnification shows the finish line position. which will be juxlagingival after repositioning. Figs g -118 to g-120 Lateral and occlusal views demonstrate the good parallelism of the preparations and the care taken to avoid injury to the gin
giva.
Figs g-121 and g-122 Elastomeric impression. Because the compression area is on the mucosal tissue and not on the teeth. the impression can
be used.
CHAPTER 9
Figs g-123 and 9-124 Extra hard plaster cast shows the accurate finish tines of the tooth preparations and welt-reproduced details. Figs 9-128and 9-129 High-noble gold copings. which witt be cemented directly onto the prepared teeth.
igs 9-125 o g-m Gold castings for double telescopic crowns for the filling i n the palienrs mouth. During the marginal adaptation. the pre Fig 9-130 Secondary structures adapted to the primary copings. The secondary structures witt be cemented inside the prosthetic framework
cision of the framework was evaluated on the cast MagnifiCatiOn ensures that the same adaptation occurs in the mouth. after electroplating.
Figs g -131 and 9-132 Definitive restoration. including the metal-reinforced prosthesis and telescopic crowns in a single block. coaled with an
esthetic resin composite ISinfony. 3M ESPEI. The esthetic coating uses one of the latest resin composites for a lighter prosthesis. The advan
tage of this type of restoration is the possibility of easily resolving any complications with one or more teeth. without having to start over
from the beginning.
310 311
CHAPTER 9
Figs g-123 and 9-124 Extra hard plaster cast shows the accurate finish tines of the tooth preparations and welt-reproduced details. Figs 9-128and 9-129 High-noble gold copings. which witt be cemented directly onto the prepared teeth.
igs 9-125 o g-m Gold castings for double telescopic crowns for the filling i n the palienrs mouth. During the marginal adaptation. the pre Fig 9-130 Secondary structures adapted to the primary copings. The secondary structures witt be cemented inside the prosthetic framework
cision of the framework was evaluated on the cast MagnifiCatiOn ensures that the same adaptation occurs in the mouth. after electroplating.
Figs g -131 and 9-132 Definitive restoration. including the metal-reinforced prosthesis and telescopic crowns in a single block. coaled with an
esthetic resin composite ISinfony. 3M ESPEI. The esthetic coating uses one of the latest resin composites for a lighter prosthesis. The advan
tage of this type of restoration is the possibility of easily resolving any complications with one or more teeth. without having to start over
from the beginning.
310 311
CHAPTER 9
R EFERENCES 12. Eames WB, Wallace SW, Suway NB, Rogers LB. Accuracy
and dimensional stability of elastomeric impression

t. Schulz HH, Schwickerath H. Die Abformung in der materials. ) Prosthet Dent 1979;42:159-162.
Zahnheilkunde. Cologne: Deutscher lrzte-Verlag, 1989. 13. Lin CC, Ziebert GJ. Donegan 51. Dhuru VB. Accuracy of
2. Richards MW, Zeiaei 5, Bagby MD, Okubo 5, Soltani ). impression materials for complete-arch ixed partial
Working times and dimensional accuracy of the one dentures. J Prosthet Dent 1988;59:288-291.
step putty/wash impression technique. J Prosthodont 14· Revised American Dental Association Specification no.
1998:7:25-255· 19 for Non-aqueous, Elastomeric Dental Impression Ma
3· Phillips RW. Science of Dental Materials, ed 9. Phila terials. J Am Dent Assoc 1977:94:733-741.
delphia: Saunders, 1991. 15. Johnson GH, Lepe X, Aw TC. The efect of surface mois·
4· Carrotte PV, Johnson A, Winstanley RB. The inluence of ture on detail reproduction of elastomeric impressions.
the impression tray on the accuracy of impressions for I Prosthet Dent 2oo3;90(4) :354-364.
crown and bridge work-An investigation and review. 16. Owen CP, Goolam R. Disinfection of impression materi
Br Dent J 199B;t85:580-585. als to prevent viral cross contamination: A review and
5· Wirz ), Scharer P, Kauhnann P. Selected acrylate resins a protocol. tnt I Prosthodont 1993;6:48o-494·
for preparation of individual mold trays [in German). 17. ADA Council on Scientiic Aairs and ADA Council on
Dent Labor 1979;27:573-580. Dental Practice. Inection control recommendations for
6. Lehner CR, Sch�rer P. Impression materials in crown· the dental oice and the dental laboratoy. I Am Dent
bridge prosthodontics. The determination of their place Assoc 1996;t27:672�.
and practical tips [in German> Schweiz Monatsschr t8. Kugel G, Pery RD, Ferrari M, Lalicata P. Disinfection and
Zahnmed 199t;tOt:62>38. communication practices: A survey of U.S. dental labo
7. Ortensi L, Strocchi ML. Modiied custom tray. ) Prosthet ratories. I Am Dent Assoc 2000;131;786-792.
Dent 2000;84:237-240. 19. Langenwalter EM, Aquilino SA, Tuner A. The dimen
8. Craig RG. Restorative Dental Materials, ed to. St Louis: sional stability of elastomeric impression materials fol
Mosby, 1997. lowing disinfection. I Prosthet Dent 1990;63:27-276.
9· Cho GC, Donovan TE, Chee W, White SN. Tensile bond 20. atyas ), Dao N, Caputo A, Lucatoto FM. Eects of
strength of polvinyl siloxane impressions bonded to a disinfectants on dimensional accuracy of impression

custom tray as a function of dying time: Pat I. J materials. I Prosthet Dent 1990;64:25-31.
Prosthet Dent 1995:73:419-423. 21. Ken M, Rathmer RM, Strub JR. Three-dimensional
to. Linke BA, Nicholls )1, Faucher RR. Distortion analysis of investigation of the accuracy of impression materials
stone casts made from impression materials. I Prosthet ater disinfection. J Prosthet Dent 1993:70:44-456.
Dent 1985:54:794-802. 22. Davis BA. Powers JM. Efect of immersion disinfection
11. Dounis GS, Zieber! G), Dounis KS. A comparison of on properties of impression materials. J Prosthodont
impression materials for complete-arch fixed patial
dentures. J Prosthet Dent 1991:65:t65-169.
ig 9-133 Definitive restoration in the mouth.

ig 9-14 Patient's smile.
312 m
CHAPTER 9
R EFERENCES 12. Eames WB, Wallace SW, Suway NB, Rogers LB. Accuracy
and dimensional stability of elastomeric impression

t. Schulz HH, Schwickerath H. Die Abformung in der materials. ) Prosthet Dent 1979;42:159-162.
Zahnheilkunde. Cologne: Deutscher lrzte-Verlag, 1989. 13. Lin CC, Ziebert GJ. Donegan 51. Dhuru VB. Accuracy of
2. Richards MW, Zeiaei 5, Bagby MD, Okubo 5, Soltani ). impression materials for complete-arch ixed partial
Working times and dimensional accuracy of the one dentures. J Prosthet Dent 1988;59:288-291.
step putty/wash impression technique. J Prosthodont 14· Revised American Dental Association Specification no.
1998:7:25-255· 19 for Non-aqueous, Elastomeric Dental Impression Ma
3· Phillips RW. Science of Dental Materials, ed 9. Phila terials. J Am Dent Assoc 1977:94:733-741.
delphia: Saunders, 1991. 15. Johnson GH, Lepe X, Aw TC. The efect of surface mois·
4· Carrotte PV, Johnson A, Winstanley RB. The inluence of ture on detail reproduction of elastomeric impressions.
the impression tray on the accuracy of impressions for I Prosthet Dent 2oo3;90(4) :354-364.
crown and bridge work-An investigation and review. 16. Owen CP, Goolam R. Disinfection of impression materi
Br Dent J 199B;t85:580-585. als to prevent viral cross contamination: A review and
5· Wirz ), Scharer P, Kauhnann P. Selected acrylate resins a protocol. tnt I Prosthodont 1993;6:48o-494·
for preparation of individual mold trays [in German). 17. ADA Council on Scientiic Aairs and ADA Council on
Dent Labor 1979;27:573-580. Dental Practice. Inection control recommendations for
6. Lehner CR, Sch�rer P. Impression materials in crown· the dental oice and the dental laboratoy. I Am Dent
bridge prosthodontics. The determination of their place Assoc 1996;t27:672�.
and practical tips [in German> Schweiz Monatsschr t8. Kugel G, Pery RD, Ferrari M, Lalicata P. Disinfection and
Zahnmed 199t;tOt:62>38. communication practices: A survey of U.S. dental labo
7. Ortensi L, Strocchi ML. Modiied custom tray. ) Prosthet ratories. I Am Dent Assoc 2000;131;786-792.
Dent 2000;84:237-240. 19. Langenwalter EM, Aquilino SA, Tuner A. The dimen
8. Craig RG. Restorative Dental Materials, ed to. St Louis: sional stability of elastomeric impression materials fol
Mosby, 1997. lowing disinfection. I Prosthet Dent 1990;63:27-276.
9· Cho GC, Donovan TE, Chee W, White SN. Tensile bond 20. atyas ), Dao N, Caputo A, Lucatoto FM. Eects of
strength of polvinyl siloxane impressions bonded to a disinfectants on dimensional accuracy of impression

custom tray as a function of dying time: Pat I. J materials. I Prosthet Dent 1990;64:25-31.
Prosthet Dent 1995:73:419-423. 21. Ken M, Rathmer RM, Strub JR. Three-dimensional
to. Linke BA, Nicholls )1, Faucher RR. Distortion analysis of investigation of the accuracy of impression materials
stone casts made from impression materials. I Prosthet ater disinfection. J Prosthet Dent 1993:70:44-456.
Dent 1985:54:794-802. 22. Davis BA. Powers JM. Efect of immersion disinfection
11. Dounis GS, Zieber! G), Dounis KS. A comparison of on properties of impression materials. J Prosthodont
impression materials for complete-arch fixed patial
dentures. J Prosthet Dent 1991:65:t65-169.
ig 9-133 Definitive restoration in the mouth.

ig 9-14 Patient's smile.
312 m
t P ER
Custom Impression Trays a n d I mpression Materials
23. Lepe X, Johnson GH, Berg JC. Surface characteristics of )2. Piwowarczyk A, Ottl P, Buchler A, Lauer HC, Hoffmann A. 42. de Camargo LM, Chee W, Donovan TE. Inhibition of 53. Daoudi MF, Setchell DJ, Searson LJ. A laboratory investi·
a polyether and addition silicone impression materials In vitro study on the dimensional accuracy of selected polymerization of polyvinyl siloxanes by medicaments gation of the accuracy of two impression techniques for
after long-term disinfection. I Prosthet Dent 1995:74: materials for monophase elastic impression making. t nt used on gingival retraction cords. I Prosthet Dent 1993: single-tooth implants. lnt I Prosthodont 200t:t4:1S2-t58.
181 186. I Prosthodont 2002:t5: t68-t74· 70:114 -117. 54· Ass r f D. Marshak B, Schmidt A. Accuracy of implant
24. Rlos MP, Morgana SM. Stein RS, Rose L. Effeas of chem )). Keck SC, Douglas WH. Tear strength of non-aqueous 43· Nissan J. Laufer BZ, Brosh T, ssif D. Accuracy of three impression techniques. t nt I Oral Maxillofac Implants
ical disinfectant solutions on the stability and accuracy rmpression materials. I Dent Res 1984:6) : 1 5 5 157. polyvinyl siloxane putty-wash impression techniques. I 1996:11:21-222.
of the dental impression complex. I Prosthet Dent 1996: 34 Salem NS, Combe EC, Watts DC. Mechanical propenres Prosthet Dent 2000;8):16t-t6s. 5 5 · Jemt . Three-dimensional distonion of gold alloy cast
·
76:) 56-)62. of elastomeric impression materials. I Oral Rehabil 44. Tjan AH, Li . Efects of reheating on the accuracy of ings and welded titanium frameworks. easurements
25. Thouati , Deveaux E. lost A. Behin P. Dimensional sta· 1988:t 5 : 12S-132. addition silicone putty-wash Impressions. I Prosthet of the precision of the it between completed implant
bility of seven elastomeric impression materials lm· 35. Tam LE, Brown JW. The tear resistance of various im· Dent 199t:65=743.748. prostheses and the master casts in routine edentulous
mersed in disinfectants. I Prosthet Dent 1996:76:8-14. pression materials with and without modifiers. J Prosthet 45· Hung SH, Purk JH. nra DE, Eick JD. Accuracy of one·step situations. 1 Oral Rehabil 1995 : 2 2 : 5 5 7-564.
26. Adabo GL, Zanarottr E. Fonseca RG, Cruz A. Effect of Dent 1990:6):282-285. versus two-step putty wash addition silicone impres 56. Jemt T, Rubenstein IE, Carlsson L, Lang BR. easuring
disinfectant agents on dimensional stability of elasto 36. Albers HF. Impressions: A Text for Selection of Materials sion technique. I Prosthet Dent •992:67: 583-589. fit at the implant prosthodontic interace. J Prosthet
meric impression materials. J Prosthet Dent 1999;81: and Techniques. Santa Rosa, A: Alto Books, 1990: 46. Nissan 1. Gross M, Shifman A, Assif D. Efect of wash Dent 1996:75:)14-324.
621-624. 45-46. bulk on the accuracy of polyvinyl siloxane putty·wash S7· Jemt . In vivo measurements of precision of it involv
27. Johnson GH, Chellis KD, Gordon GE, Lepe X. Dimen· 37· Purk )H, Willes MG, Tira DE, Eick JD, Hung SH. The impressions. I Oral Rehabil 2002;29:35 7-)61. ing implant-suppoted prostheses in the edentulous jaw.
sional stability and detail reproduction of irreversible effects of diferent storage conditions on polyether and 47. Giordano R 2nd. Issues in handling impression materi lnt I Oral axilloac Implants 1996: 1 1 : t 5 1-158.
hydrocolloid and elastomeric impressions disinfected polyvinylsiloxane impressions. I Am Dent Assoc 1998: als. Gen Dent 2000:48:646-648. 58. Jemt T, Book K. Prosthesis misfit and marginal bone
by immersion. J Prosthet Dent 1998:79=44-453· 129:1014-1021. 48. Spector MR, Donovan TE, Nicholls 11. An evaluation of loss in edentulous implant patients. lnt I Oral axillofac
28. cCabe )F, Walls AW. Impression materials: Classifi 38. Corso M, Abanomy A, Di Canzio J. Zurakowski D, impression techniques for osseointegrated implants. I Implants 1996:11:62o625.
cation and requirements. In: Mccabe JF. Walls AWG Morgana SM. The effect of temperature changes on the Prosthet Dent 1990:63:444-447· S9· Wee AG. Comparison of impression materials for direct
(eds). Applied Dental Materials, ed 8. Oxford: Blackwell dimensional stability of polyvinyl siloxane and poly· 49· Hsu CC. Millstein PL. Stein RS. A comparative analysis multi-implant impressions. I Prosthet Dent 2000:83:
Science, 1998:1 18-126. ether impression materials. I Prosthet Dent 1998:79: of the accuracy of implant transfer techniques. J 32)-))1.
29. Lepe X, Johnson GH, Berg )(, Aw TC, Stroh GS. Wetta 626-6)1. Prosthet Dent 1993:69:s88-s93· 6o. Romero GG, Engelmeier R, Powers )M, Canterbuy A.
bility, imbibition, and mass change of disinfected low· 39· Lee A. Predictable elastomeric impressions in ad· so. Phillips KM, Nicholls 11. Ma T, Rubenstein )E. The accu· Accuracy of three corrective techniques for implant bar
viscosity impression materials. J Prosthet Dent 2002;88: vanced fixed prosthodontics: A comprehensive review. racy of three implant impression techniques: A three fabrication. I Prosthet Dent 2000:84:6o2-607.
268-276. Pract Periodontics Aesthet Dent 1999:11:497-504. dimensional analysis. lnt I Oral Maxillofac Implants 61. Assif D, Nissan J. a rsano I, Singe r A. Accuracy of im
30. Ragarn )(, Grosko ML, Raj M, Ryan TN, Johnston WM. 40. Keck SC. Automixing: A new concept ln elastomeric •994:9=533-540. plant impression splinted techniques: Efect of splinting
Detail reproduction, contact angles, and die hardness of impression material delivey systems. J Prosthet Dent 51. Riedy SJ, Lang BR, Lang BE. Fit of implant frameworks material. lnt J Oral axilloac Implants 1999:14 :88s-888.
elastomeric impression and gypsum die material com· 1985 : 54=479-48). fabricated by diferent techniques. J Prosthet Dent 1997: 62. Wise M. Fit of implant-suppMed fixed prostheses fab
binations. lnt J Prosthodont 2oo; t):214-22o. 41. Wil liams PT, Jackson DG, Bergman W. An evaluation of 78:596-6o4. ricated on master casts made from a dental stone and
31. Clancy JM, Scandrett FR, Ettinger RL Long-term dimen the time-dependent dimensional stability of eleven 52. Wee AG, Aquilino SA, Schneider RL. Strategies to a dental plaster. I Prosthet Dent 200t;86:sJ2-5J8.
sional stabrlity of three current elastomers. I Oral Rehabil elastomeric impression materials . I Prosthet Dent 1984; achieve fit in implant prosthodontics: A review of the lit
t983:tO:J2S-333· S 2 : t 2o-t2S. erature. lnt I Prosthodont 1999:t2:t67-178.
314 3t5
t P ER
Custom Impression Trays a n d I mpression Materials
23. Lepe X, Johnson GH, Berg JC. Surface characteristics of )2. Piwowarczyk A, Ottl P, Buchler A, Lauer HC, Hoffmann A. 42. de Camargo LM, Chee W, Donovan TE. Inhibition of 53. Daoudi MF, Setchell DJ, Searson LJ. A laboratory investi·
a polyether and addition silicone impression materials In vitro study on the dimensional accuracy of selected polymerization of polyvinyl siloxanes by medicaments gation of the accuracy of two impression techniques for
after long-term disinfection. I Prosthet Dent 1995:74: materials for monophase elastic impression making. t nt used on gingival retraction cords. I Prosthet Dent 1993: single-tooth implants. lnt I Prosthodont 200t:t4:1S2-t58.
181 186. I Prosthodont 2002:t5: t68-t74· 70:114 -117. 54· Ass r f D. Marshak B, Schmidt A. Accuracy of implant
24. Rlos MP, Morgana SM. Stein RS, Rose L. Effeas of chem )). Keck SC, Douglas WH. Tear strength of non-aqueous 43· Nissan J. Laufer BZ, Brosh T, ssif D. Accuracy of three impression techniques. t nt I Oral Maxillofac Implants
ical disinfectant solutions on the stability and accuracy rmpression materials. I Dent Res 1984:6) : 1 5 5 157. polyvinyl siloxane putty-wash impression techniques. I 1996:11:21-222.
of the dental impression complex. I Prosthet Dent 1996: 34 Salem NS, Combe EC, Watts DC. Mechanical propenres Prosthet Dent 2000;8):16t-t6s. 5 5 · Jemt . Three-dimensional distonion of gold alloy cast
·
76:) 56-)62. of elastomeric impression materials. I Oral Rehabil 44. Tjan AH, Li . Efects of reheating on the accuracy of ings and welded titanium frameworks. easurements
25. Thouati , Deveaux E. lost A. Behin P. Dimensional sta· 1988:t 5 : 12S-132. addition silicone putty-wash Impressions. I Prosthet of the precision of the it between completed implant
bility of seven elastomeric impression materials lm· 35. Tam LE, Brown JW. The tear resistance of various im· Dent 199t:65=743.748. prostheses and the master casts in routine edentulous
mersed in disinfectants. I Prosthet Dent 1996:76:8-14. pression materials with and without modifiers. J Prosthet 45· Hung SH, Purk JH. nra DE, Eick JD. Accuracy of one·step situations. 1 Oral Rehabil 1995 : 2 2 : 5 5 7-564.
26. Adabo GL, Zanarottr E. Fonseca RG, Cruz A. Effect of Dent 1990:6):282-285. versus two-step putty wash addition silicone impres 56. Jemt T, Rubenstein IE, Carlsson L, Lang BR. easuring
disinfectant agents on dimensional stability of elasto 36. Albers HF. Impressions: A Text for Selection of Materials sion technique. I Prosthet Dent •992:67: 583-589. fit at the implant prosthodontic interace. J Prosthet
meric impression materials. J Prosthet Dent 1999;81: and Techniques. Santa Rosa, A: Alto Books, 1990: 46. Nissan 1. Gross M, Shifman A, Assif D. Efect of wash Dent 1996:75:)14-324.
621-624. 45-46. bulk on the accuracy of polyvinyl siloxane putty·wash S7· Jemt . In vivo measurements of precision of it involv
27. Johnson GH, Chellis KD, Gordon GE, Lepe X. Dimen· 37· Purk )H, Willes MG, Tira DE, Eick JD, Hung SH. The impressions. I Oral Rehabil 2002;29:35 7-)61. ing implant-suppoted prostheses in the edentulous jaw.
sional stability and detail reproduction of irreversible effects of diferent storage conditions on polyether and 47. Giordano R 2nd. Issues in handling impression materi lnt I Oral axilloac Implants 1996: 1 1 : t 5 1-158.
hydrocolloid and elastomeric impressions disinfected polyvinylsiloxane impressions. I Am Dent Assoc 1998: als. Gen Dent 2000:48:646-648. 58. Jemt T, Book K. Prosthesis misfit and marginal bone
by immersion. J Prosthet Dent 1998:79=44-453· 129:1014-1021. 48. Spector MR, Donovan TE, Nicholls 11. An evaluation of loss in edentulous implant patients. lnt I Oral axillofac
28. cCabe )F, Walls AW. Impression materials: Classifi 38. Corso M, Abanomy A, Di Canzio J. Zurakowski D, impression techniques for osseointegrated implants. I Implants 1996:11:62o625.
cation and requirements. In: Mccabe JF. Walls AWG Morgana SM. The effect of temperature changes on the Prosthet Dent 1990:63:444-447· S9· Wee AG. Comparison of impression materials for direct
(eds). Applied Dental Materials, ed 8. Oxford: Blackwell dimensional stability of polyvinyl siloxane and poly· 49· Hsu CC. Millstein PL. Stein RS. A comparative analysis multi-implant impressions. I Prosthet Dent 2000:83:
Science, 1998:1 18-126. ether impression materials. I Prosthet Dent 1998:79: of the accuracy of implant transfer techniques. J 32)-))1.
29. Lepe X, Johnson GH, Berg )(, Aw TC, Stroh GS. Wetta 626-6)1. Prosthet Dent 1993:69:s88-s93· 6o. Romero GG, Engelmeier R, Powers )M, Canterbuy A.
bility, imbibition, and mass change of disinfected low· 39· Lee A. Predictable elastomeric impressions in ad· so. Phillips KM, Nicholls 11. Ma T, Rubenstein )E. The accu· Accuracy of three corrective techniques for implant bar
viscosity impression materials. J Prosthet Dent 2002;88: vanced fixed prosthodontics: A comprehensive review. racy of three implant impression techniques: A three fabrication. I Prosthet Dent 2000:84:6o2-607.
268-276. Pract Periodontics Aesthet Dent 1999:11:497-504. dimensional analysis. lnt I Oral Maxillofac Implants 61. Assif D, Nissan J. a rsano I, Singe r A. Accuracy of im
30. Ragarn )(, Grosko ML, Raj M, Ryan TN, Johnston WM. 40. Keck SC. Automixing: A new concept ln elastomeric •994:9=533-540. plant impression splinted techniques: Efect of splinting
Detail reproduction, contact angles, and die hardness of impression material delivey systems. J Prosthet Dent 51. Riedy SJ, Lang BR, Lang BE. Fit of implant frameworks material. lnt J Oral axilloac Implants 1999:14 :88s-888.
elastomeric impression and gypsum die material com· 1985 : 54=479-48). fabricated by diferent techniques. J Prosthet Dent 1997: 62. Wise M. Fit of implant-suppMed fixed prostheses fab
binations. lnt J Prosthodont 2oo; t):214-22o. 41. Wil liams PT, Jackson DG, Bergman W. An evaluation of 78:596-6o4. ricated on master casts made from a dental stone and
31. Clancy JM, Scandrett FR, Ettinger RL Long-term dimen the time-dependent dimensional stability of eleven 52. Wee AG, Aquilino SA, Schneider RL. Strategies to a dental plaster. I Prosthet Dent 200t;86:sJ2-5J8.
sional stabrlity of three current elastomers. I Oral Rehabil elastomeric impression materials . I Prosthet Dent 1984; achieve fit in implant prosthodontics: A review of the lit
t983:tO:J2S-333· S 2 : t 2o-t2S. erature. lnt I Prosthodont 1999:t2:t67-178.
314 3t5
C H A P T E R 1 0
L A B O RAT O R Y P R O C E D U RES
FIG 10-1 FIG 10-2
C R EATI O N OF THE W O R K I N G CAST Because plaster is compatible with all i mpression

materials and can be used with the various comput
I m pression a nalysis
erized scanning systems (computer-aided design/com W O R K I N G C A S T S Y S T E M S
puter assisted manufacturing ICAD/CAMD. it is the
High-quality restorations begin with correct impres material of choice for making casts. Using plaster
sions, since errors and minor defects in the impres guarantees predictable results from practical and
sion are inevitably transferred to the working cast well-tested techniques.
and may compromise the final adaptation of the Plaster also is the most economical material avail
restoration. The dental technician must not only able for cast fabrication, and in addition to its pre
take perfect impressions in the laboratory, but also cision, it ofers the hardness and compression resis
examine them carefully under the microscope to con tance essential to working on a cast without risking
irm that their dimensions and detail reproduction surface damage.J-7 Varieties of plaster are classified
are precise (Fig 10-1). Once the accuracy of the im in terms of their degree of expansion, flexion, com
pression is confirmed, extreme care must be taken pression resistance, and hardness. The most common
to avoid introducing mistakes during the fabrication types are natural plasters fortified with low-expansion
of the master cast to guarantee optimal adaptation synthetic resin6 (ResinRock, Whip Mix), which offer
FIG 10-J FIG 1 0-4
and integration of the restoration i n the oral cavity. high resistance to abrasion and scratches,6.8 good
plasticity, dimensional stability comparable to that
of the finest type IV plasters, and favorable volu
Materials for master working casts
metric expansion ranging from o.o7% to o.o8%.
The technician selects a cast material that is com Alternatives to plaster include epoxy and poly
patible with the type of cast to be made and the urethane resins. Unlike plasters, which expand, these
type of impression material that was used, because materials are characterized by volumetric shrinkage
interaction between incompatible materials can give of o.os%. but they have been shown to provide Fig 10-1 To create a working cast with good dimensional precision and excellent detail reproduction. the dentat technician must work with a
rise to imperfections.'·' Manufacturers offer a vast precise detail reproduction. Their two basic compo precise impression. Note the detailed reproduction of the finish tine.
Figs 10-2 and 10-3 Ouatity of the restoration atso depends on the precision of the master cast. Each stage must be performed using tho appro
range of construction systems (eg, Model-Tray System, nents, resin and polyamine, begin to polymerize as
priate materials and systems.
Model-Tray) and cast materials, such as plasters and soon as they are mixed; the resin must be poured Fig 10-4 Plaster cast from a reversible hydrocolloid impression. Given the water absorption and secretion of hydrocolloid materials. the tech
polyurethane and epoxy resins. immediately into the impression while it remains in .. nician must pour a cast within 10 minutes of taking the impression.
311 317
C H A P T E R 1 0
L A B O RAT O R Y P R O C E D U RES
FIG 10-1 FIG 10-2
C R EATI O N OF THE W O R K I N G CAST Because plaster is compatible with all i mpression

materials and can be used with the various comput
I m pression a nalysis
erized scanning systems (computer-aided design/com W O R K I N G C A S T S Y S T E M S
puter assisted manufacturing ICAD/CAMD. it is the
High-quality restorations begin with correct impres material of choice for making casts. Using plaster
sions, since errors and minor defects in the impres guarantees predictable results from practical and
sion are inevitably transferred to the working cast well-tested techniques.
and may compromise the final adaptation of the Plaster also is the most economical material avail
restoration. The dental technician must not only able for cast fabrication, and in addition to its pre
take perfect impressions in the laboratory, but also cision, it ofers the hardness and compression resis
examine them carefully under the microscope to con tance essential to working on a cast without risking
irm that their dimensions and detail reproduction surface damage.J-7 Varieties of plaster are classified
are precise (Fig 10-1). Once the accuracy of the im in terms of their degree of expansion, flexion, com
pression is confirmed, extreme care must be taken pression resistance, and hardness. The most common
to avoid introducing mistakes during the fabrication types are natural plasters fortified with low-expansion
of the master cast to guarantee optimal adaptation synthetic resin6 (ResinRock, Whip Mix), which offer
FIG 10-J FIG 1 0-4
and integration of the restoration i n the oral cavity. high resistance to abrasion and scratches,6.8 good
plasticity, dimensional stability comparable to that
of the finest type IV plasters, and favorable volu
Materials for master working casts
metric expansion ranging from o.o7% to o.o8%.
The technician selects a cast material that is com Alternatives to plaster include epoxy and poly
patible with the type of cast to be made and the urethane resins. Unlike plasters, which expand, these
type of impression material that was used, because materials are characterized by volumetric shrinkage
interaction between incompatible materials can give of o.os%. but they have been shown to provide Fig 10-1 To create a working cast with good dimensional precision and excellent detail reproduction. the dentat technician must work with a
rise to imperfections.'·' Manufacturers offer a vast precise detail reproduction. Their two basic compo precise impression. Note the detailed reproduction of the finish tine.
Figs 10-2 and 10-3 Ouatity of the restoration atso depends on the precision of the master cast. Each stage must be performed using tho appro
range of construction systems (eg, Model-Tray System, nents, resin and polyamine, begin to polymerize as
priate materials and systems.
Model-Tray) and cast materials, such as plasters and soon as they are mixed; the resin must be poured Fig 10-4 Plaster cast from a reversible hydrocolloid impression. Given the water absorption and secretion of hydrocolloid materials. the tech
polyurethane and epoxy resins. immediately into the impression while it remains in .. nician must pour a cast within 10 minutes of taking the impression.
311 317
CHA
Laboratoy Procedures I
"" the plastic phase and, because of its sensitivity to that greatly si mplifies the laboratory procedures and "" 10-6). This layer of polyurethane resin prevents care is taken to safeguard all pertinent anatomic
moisture, kept in a dry environment. thus reduces the potential for material difficulties. expansion of the plaster cast from absorption of the information. The dies are then repositioned in the
I n general, polyurethane resins (PX Extrarock, PX The Zeiser system (Zeiser Dental) is composed of bonder of the Plexiglas base, which would alter the impression, and a plaster cast of the remaining arch
Dental) are not compatible with all impression mate a removable cast that is easily inserted into a Plexi cast's physicochemical characteristics. is poured. The result is a working cast that pre
rials and should not be used with either polysulfide glas base. Unlike the Pindex system from which it The dies must be separated by hand, preferably seves the anatomic details of the soft tissues while
or hydrocolloid impressions. Although they are com evolved, the Zeiser system guarantees precise adap using the microscope, for optimal control and to permitting the technician to work with removable
patible with polyethers, an isolating product (PX tation of the cast material and this Plexiglas (former prevent accidental damage to the preparation resin dies that precisely imitate the radicular anato
Extrarock D, PX Dental) should be used to prevent ly plaster) base, and thus greater control of linear edges. However, for a fixed partial denture, the tech my of each individual tooth (Figs 10-11 and 10-12).
bonding between the i mpression material and the though not volumetric- movement. Brass pins in the nician should keep the area together in a block Such an anatomic cast is an optimum reproduction
resin. base of each sectioned part are adapted to the rather than separating individual dies (Fig 10·7). of the clinical situation, and it proves very useful for
The obvious diferences between resin and plas Plexiglas base by means of calibrated, heat-aided Keeping the restoration section in one piece gives subsequent restoration phases (Figs 10-13 to 10-16).
ter concern their respective expansion and contrac drilling, providing optimal stability to each remov the technician maximum stability and preserves the The Model System (Tricodent) 13 for preparing a
tion properties. Nonetheless, findings of dimension able die.10·u distances between the dies and thus the exact working cast is easy, practical, and economic. The
al testing9- 10 to assess differences in detail repro During preparation of the master cast, the pre dimensions of the clinical situation. Taking this pre system includes a special plastic box for holding the
duction indicate that casts made from both materials pared dies are coated with a special silicone (Pro caution assumes even greater importance when a plaster cast; this box is equipped with internal ver
reproduce details accurately. When compared, neither tector, Benzer Dental) to create a protective film that ceramic margin (36o-degree or collarless) is planned tical grooves for repositioning the dies and two side
epoxy resin shrinkage nor plaster expansion has a will be removed only when the cast is complete (Figs for the entire circumference of the restoration or clips that can open to block the plaster model: on
signiicant clinical efect. When appropriate procedures 10-2 and 10·3). when the shoulder portion of the ceramic is layered the back are two small rest levers that permit com
are followed, both materials meet the American In pouring the cast, particular attention should be solely on the buccal surface. plete extraction. The borders of the impression are
Dental Association (ADA) guidelines for a precision paid to the intrinsic properties of the i mpression To facilitate subsequent procedures carried out in rounded of, leaving a distance of at least 6 mm
crown ater cementation. material. Hydrocolloids, for example, limit normal making the wax pattern, such as trimming the mar from the gingival tissues, so it is possible to mark
Breakage and wear resistance are the most impor laboratory procedures and require modified cast prep gins (or allowing for the possibility of ceramic mar the midline so as to facilitate alignment of the
tant properties that distinguish the two materials. aration. Because hydrocolloids vary dimensionally gins), a laboratory bur should be used to remove impression with the central axis in the Tricodent sys
Because of its hardness. an epoxy resin cast is less through water absorption and secretion, the plaster plaster in the areas corresponding to the mucous tem. During this construction phase the two black
fragile and therefore maintains details and precision 10 cast must be developed in 10 minutes or less. Such membrane in the edentulous zone (Fig 10·8).12 To closure clips are adapted and, once the base has
better during laboratory procedures and generates time restriction precludes the possibility of creating record the details of the soft tissue in the edentu· been isolated with a silicone material, the impres
less stress for the dental technician. a Zeiser-type master cast directly from hydrocolloid lous zone, a rigid silicone cast (Gingifast Rigid, sion is cast by filling the tray with type IV extra-hard
Since both plaster and resin materials are subject impressions. Therefore, if hydrocolloids are used, the Zhermack) can be used to allow easy repositioning plaster. Before the plaster hardens, the impression
to aging and deterioration, technicians also must be clinician must immediately pour a cast (Fig 10-4) on the master cast as needed (Figs 10-9 and 10-10). tray is positioned upside-down on the system, taking
aware of expiration dates, especially once the pack using a vacuum mixer and send it to the laboratory Alternatively, a polyurethane resin cast (PX Extra care to remove all excess material. Single-plaster
age has been opened.•-6-1o for fabrication of the master cast. rock) can be made using only the individual dies casting is one of the advantages of modern systems
Afteward, the prepared dies are covered with iso that are involved rather than the entire arch. The (Fig 10·17)- 10,1 1,14.15 ..
lating silicone, and the plaster is trimmed with a dy individual master dies of resin are roughed out, and
Systems a n d methods for cast
cast squaring machine (Trimex Px 1000, Micerium).
construction
Following the Zeiser technique, the technician layers
To ensure the stability of the working cast, the dental low-contraction polyurethane resin (PX Extrarock)
technician can use a technique for cast construction between the cast and Plexiglas base (Figs 10-5 and .
318 319
CHA
"" the plastic phase and, because of its sensitivity to that greatly si mplifies the laboratory procedures and "" 10-6). This layer of polyurethane resin prevents care is taken to safeguard all pertinent anatomic
moisture, kept in a dry environment. thus reduces the potential for material difficulties. expansion of the plaster cast from absorption of the information. The dies are then repositioned in the
I n general, polyurethane resins (PX Extrarock, PX The Zeiser system (Zeiser Dental) is composed of bonder of the Plexiglas base, which would alter the impression, and a plaster cast of the remaining arch
Dental) are not compatible with all impression mate a removable cast that is easily inserted into a Plexi cast's physicochemical characteristics. is poured. The result is a working cast that pre
rials and should not be used with either polysulfide glas base. Unlike the Pindex system from which it The dies must be separated by hand, preferably seves the anatomic details of the soft tissues while
or hydrocolloid impressions. Although they are com evolved, the Zeiser system guarantees precise adap using the microscope, for optimal control and to permitting the technician to work with removable
patible with polyethers, an isolating product (PX tation of the cast material and this Plexiglas (former prevent accidental damage to the preparation resin dies that precisely imitate the radicular anato
Extrarock D, PX Dental) should be used to prevent ly plaster) base, and thus greater control of linear edges. However, for a fixed partial denture, the tech my of each individual tooth (Figs 10-11 and 10-12).
bonding between the i mpression material and the though not volumetric- movement. Brass pins in the nician should keep the area together in a block Such an anatomic cast is an optimum reproduction
resin. base of each sectioned part are adapted to the rather than separating individual dies (Fig 10·7). of the clinical situation, and it proves very useful for
The obvious diferences between resin and plas Plexiglas base by means of calibrated, heat-aided Keeping the restoration section in one piece gives subsequent restoration phases (Figs 10-13 to 10-16).
ter concern their respective expansion and contrac drilling, providing optimal stability to each remov the technician maximum stability and preserves the The Model System (Tricodent) 13 for preparing a
tion properties. Nonetheless, findings of dimension able die.10·u distances between the dies and thus the exact working cast is easy, practical, and economic. The
al testing9- 10 to assess differences in detail repro During preparation of the master cast, the pre dimensions of the clinical situation. Taking this pre system includes a special plastic box for holding the
duction indicate that casts made from both materials pared dies are coated with a special silicone (Pro caution assumes even greater importance when a plaster cast; this box is equipped with internal ver
reproduce details accurately. When compared, neither tector, Benzer Dental) to create a protective film that ceramic margin (36o-degree or collarless) is planned tical grooves for repositioning the dies and two side
epoxy resin shrinkage nor plaster expansion has a will be removed only when the cast is complete (Figs for the entire circumference of the restoration or clips that can open to block the plaster model: on
signiicant clinical efect. When appropriate procedures 10-2 and 10·3). when the shoulder portion of the ceramic is layered the back are two small rest levers that permit com
are followed, both materials meet the American In pouring the cast, particular attention should be solely on the buccal surface. plete extraction. The borders of the impression are
Dental Association (ADA) guidelines for a precision paid to the intrinsic properties of the i mpression To facilitate subsequent procedures carried out in rounded of, leaving a distance of at least 6 mm
crown ater cementation. material. Hydrocolloids, for example, limit normal making the wax pattern, such as trimming the mar from the gingival tissues, so it is possible to mark
Breakage and wear resistance are the most impor laboratory procedures and require modified cast prep gins (or allowing for the possibility of ceramic mar the midline so as to facilitate alignment of the
tant properties that distinguish the two materials. aration. Because hydrocolloids vary dimensionally gins), a laboratory bur should be used to remove impression with the central axis in the Tricodent sys
Because of its hardness. an epoxy resin cast is less through water absorption and secretion, the plaster plaster in the areas corresponding to the mucous tem. During this construction phase the two black
fragile and therefore maintains details and precision 10 cast must be developed in 10 minutes or less. Such membrane in the edentulous zone (Fig 10·8).12 To closure clips are adapted and, once the base has
better during laboratory procedures and generates time restriction precludes the possibility of creating record the details of the soft tissue in the edentu· been isolated with a silicone material, the impres
less stress for the dental technician. a Zeiser-type master cast directly from hydrocolloid lous zone, a rigid silicone cast (Gingifast Rigid, sion is cast by filling the tray with type IV extra-hard
Since both plaster and resin materials are subject impressions. Therefore, if hydrocolloids are used, the Zhermack) can be used to allow easy repositioning plaster. Before the plaster hardens, the impression
to aging and deterioration, technicians also must be clinician must immediately pour a cast (Fig 10-4) on the master cast as needed (Figs 10-9 and 10-10). tray is positioned upside-down on the system, taking
aware of expiration dates, especially once the pack using a vacuum mixer and send it to the laboratory Alternatively, a polyurethane resin cast (PX Extra care to remove all excess material. Single-plaster
age has been opened.•-6-1o for fabrication of the master cast. rock) can be made using only the individual dies casting is one of the advantages of modern systems
Afteward, the prepared dies are covered with iso that are involved rather than the entire arch. The (Fig 10·17)- 10,1 1,14.15 ..
lating silicone, and the plaster is trimmed with a dy individual master dies of resin are roughed out, and
Systems a n d methods for cast
cast squaring machine (Trimex Px 1000, Micerium).
construction
Following the Zeiser technique, the technician layers
To ensure the stability of the working cast, the dental low-contraction polyurethane resin (PX Extrarock)
technician can use a technique for cast construction between the cast and Plexiglas base (Figs 10-5 and .
318 319
CHAPTER 1 0
Fig 10-5 Creating a Zeiser-type master cast from a hydrocolloid impression requires a different procedure than that used lor a polyether
impression. It is necessary to modify the development of the impression on the basis of the material itself. Fig 10-6 Layering polyurethane
resin between the cast and the Plexiglas base guarantees better dimensional stability lor the whole system. Fig 10-7 In the case of a fixed
partial denture. the cast should be sectioned into blocks to improve stability between dies and reduce movement between the elements of
the connected structure. Fig 10-8 Block-cut cast used to create a cermet fixed partial denture with a ceramic micromargin. Fig 10-9 Gingival
reproduction in rigid silicone is necessary to prevent loss of soft tissue detail in the edentulous zone and monitor the progress of the gingiva.
Fig 10-1D Definitive restoration in situ. Note the integration with the soft tissue as well as the stability and precision of the fixed partial den
ture. Fig 1D-11 Construction of a master cast with removable dies in polyurethane resin. This type of cast accurately records soft tissue detail
in the plaster. Fig 1D-12 Definitive cermet crown with a ceramic micromargin on the removable die. This type of cast makes it possible to
remove an individual die from the cast. which facilitates work. Figs 10-13 to 10-16 Perfect correspondence between the master cast and the
postcementation clinical situation for both the right and left lateral sectors. respectively. The construction of this type of cast can effective
ly reproduce the oral cavity. Fig 1D-17 Tricodent-type master cast. equipped with a plastic base. The correct position of the removable dies is
guaranteed by the grooves inside the box and the lateral blockage system. which uses special sell-blocking clips.
321
o
CHAPTER 1 0
Fig 10-5 Creating a Zeiser-type master cast from a hydrocolloid impression requires a different procedure than that used lor a polyether
impression. It is necessary to modify the development of the impression on the basis of the material itself. Fig 10-6 Layering polyurethane
resin between the cast and the Plexiglas base guarantees better dimensional stability lor the whole system. Fig 10-7 In the case of a fixed
partial denture. the cast should be sectioned into blocks to improve stability between dies and reduce movement between the elements of
the connected structure. Fig 10-8 Block-cut cast used to create a cermet fixed partial denture with a ceramic micromargin. Fig 10-9 Gingival
reproduction in rigid silicone is necessary to prevent loss of soft tissue detail in the edentulous zone and monitor the progress of the gingiva.
Fig 10-1D Definitive restoration in situ. Note the integration with the soft tissue as well as the stability and precision of the fixed partial den
ture. Fig 1D-11 Construction of a master cast with removable dies in polyurethane resin. This type of cast accurately records soft tissue detail
in the plaster. Fig 1D-12 Definitive cermet crown with a ceramic micromargin on the removable die. This type of cast makes it possible to
remove an individual die from the cast. which facilitates work. Figs 10-13 to 10-16 Perfect correspondence between the master cast and the
postcementation clinical situation for both the right and left lateral sectors. respectively. The construction of this type of cast can effective
ly reproduce the oral cavity. Fig 1D-17 Tricodent-type master cast. equipped with a plastic base. The correct position of the removable dies is
guaranteed by the grooves inside the box and the lateral blockage system. which uses special sell-blocking clips.
321
o
I hi· fltll',lt IH,i· llllh •I 11•·11 ·.il.rrpt·flt·d Hl',lttJrt••·ul ·.lfll
11.11 Ill ,J
•,t olltJf'l l i l , Jli J tJ
lf·i llfiS I H''(MtHt t)uf tuu' IIIS t .;•,t , l t u• lt•t h f l l t l.m Jit••t I',IIHJ 1·. �··,•,,. , , , , , , 1 I(Jr .;lf,jJJI.,I It;lt ,, , Uw , , ..,
I •I (ifi'P·H•· IHW. h II lito oil f t••,•, IJ·,u·� ·.p�·t "' ' di.JirttHJtl I'H·illtHI "'·H.Ifl , .wtf t tJr rH t .;pit oil t. tJrtltJIH'• t;l tiH·
iHW� jMh•tllt'fi b t tllii •HJIIIIJI'II �� 1 '11J t}/tJ .uuj l�11 IJI,tJ, t ft1lltl'• •itt• t·JI•t ut1•d llll h dtUt•tl·ttl fltii•At lltu·•,
(tJifjt•tJ IIJ-11 W,<d 111 lt,l '•IJH•tl, I ll•• Jw·, ,,,, {J I JIItlidl ,;tf,iiJI .illtltl ltlf f i 'JIfl ' h (JIJ',',Ibh• lll l h
. IKfltotl ltJ f•lrl'' '' •,tJIIIto .lflKit,, tm t lw pl.1';1i•r tH

d •· • f•lltt•• r ml'f,; l tJt C f•f,iflllt u••�ttJfoiWJII trl •H.Ifl'• • ptt}/llf
,•,, ,, , ,,Jt, ,..,.,;1111� lh•· lltll.,h llru .;ud t l u• ptulitm •·d t t w r •· ,Jt•• , , , t w.,t•• t•·tllt ,,, .;wl tUJrj/tHrt.;l .w.;
IJf III I(Hf"IJM<d ltJIJIIi l t iJI I Utto •11Jll dl It; 111•11 litH• ltJitlll I IJIIIIJIJf', (11• , tJi•ltJid tJf hiHI/CJIIt.;( ,ifld/tH ll'f
Ht•t oJIJ•,t• lut (j,Y IJf flloHt l flS llt� "' '' 'K i t l .wd t i t• HI,. l lt ,;l t;ll'f .wd ';IJl;t t)flllJUf',) (f j�'; 1J IJ ,J rUJ 1J I JJ.
I IJifl l ifiHfll',ltl� thto (lft< i i "JIIHJ IJf liu• dt•fltllll/t' tt·•lltHoi I IH IMffl,;l t H111t1 !lf••p.;r,,wm·�. tht• dt••,l1 tJf Htr•
IJtJII 11 l lJU"ildt•(l;tJif•, lflr• oHJihtH'o (t'I OHiflli•lld J'.IfiJS ,j fhtJ•.t• I tnt• J•, ltti'MHI.H, ·t.;rVhiM .rt t tJfdtn� to tiJt• pl.;nc••,
llllt r,tiJ[W ll lg 111 Il) .uuJ �··tJffi H r y of lht• jlfl·p.lr.Hicm , ,111d u•q ul rt· •, go'·'''''
f /�II fiiJr�irrg dl ltl�lt Hr•I,IIIfll .t!IIJII , 1 1 • lt•d lll[l r,m t tHit f•tJlf,,lltHI IJy I t!'' dr•ut.;l fl•tllnid.lfl. l h•• pn•pM.J
ilii rw�d 111 ' "''"'·" ·•i'l""""·"'' '' "" trlgtr qu.illlt ln tlcm ftH pdrtldl c r tJ WI I 'l mu•A tw dt·VtJid ol undr•rc ur•,
•,t HJifltlfll� Ill prrtrul r•tttJf f rtJfrl tilt� vl tu .H I II t;l •HI .wd tH 1!,,,,. ,Jdt•qu,,lt• rt•tt•lllltHI', lc�r lh• XtJid
uw.uii,J!Jit� l1tJf f1 rt'HIO/to @ l i �I V.i fflHrl t h •" t.J•,t, ttu r• .. ,ttJt,JIItm Cwltit h c.w oltt•f! br• thr• w.rtl•, , htJYt••, ,
l �<tllllltl•l tl IJtoKIW. wUii ,, f 'J i tihiint•t••r mu11d ,ifll[ �IIJIIYI", tJf 1 ) 11• [lll'[l •lr•llirII fl ',t•tfJ (f iR 10 111)
'"''"''""' tmr C!•Jr .'•',o), " '"' h h ·.urr.ohl•· I•JI ''''tl' 111t1 '' '" ' ' ""' '' ' " pill'. , wlr l ll ·,)ltHJid r••m.1tn lnr.ll t In
p l •1f l t• r •Jtld t-ptul r-�Au wtwn u•.�ltl{ •I I 'J , tJt;tJ rpru
"''' ''"''"''" Cf ig 111 I'll Mrlllrr� •'"'"''' "" '"' '' " v••ry lhlriH llu· rrrii iiJ'•"'P''• lht• lt•t hlllt l.rn m.rrk� rt11• fog 10 18 Rou11ne un at megnlllctlton tllowl ltchniCIInl r o 1m pro•• lhlir qutlrtatr•• 1tandards Note the ergonomiC posture ol the operator.
f1g 10 19 Roughtng out the muter cu r lntllllly. lht g1ng•u reproductd In pluter Is tlom1na1td under magn1f1ut1on w1th 1 ball d11mond bur
,,,.,,, ,,, ..,.(, P•Htlt IJI.trll (I !I ,,,,jjfl•f t ,, •• , llhl•(l• ptJlH tl m i r tJf llu· [tr••rw.rlltJrr w.lng .r "IIIJr••tl p••rr<ll. l h••
with the utm01t cere l l k t n r o IV Old sccrdonlllly d a m s g • n g the d11 F1g 10-20 A fter lhe f i ( S I tllge. the techn1mn cont1nuu With a cylindrical
rt-'.ht.Ht t to ltJ ,1JJf,t�lrm .md l �l lth •nt ; ltJ •,ptJnr,•r rno�Yt••, prt•p,or.rriiJII lhrrl! •, fill I IHII p lt• rt• liJWfl', ftJtiOW .r rPK dltmond bur thll ls tbout l 5 mm long tnd hu a t1pered stsm to priVtnt lntdverttnt contact With the f1nlsh line Th11 bur 18350 Komett per
mill the ltchnlcltn to con1truct the rtdlcultr profile t pi c t l l y. by gelling cion to the l1nl1h ltnt w l t hou r runnrng the risk of damag�ng it
II '" ' 1 •·•'• / rn muntl 1111 ''"�'"• I "'"Y '" " ' pt�ly ui.H, t tiii�I•HII UJUf'1l• Orl l ilt• '••Hill' p{,if1(', whitt• lWi11 frg 10 71 Prepmtion ot lhl die prairie The reproduction of the tru tplul to the iln11h tine 11 11n11hed manually under h1gh magnilicat1on
tHt•l lt.wto ,,.�.tn t •�'• ' ) t;tft•t S''"•if � r Wl•.ff rt·�l�tt•nu �. fm p.lll l.r l 1 r tJW f l', "'' lrrt•grrl.tr .rnd on dllf••rt•rll
wirh a we t i - eh tr pen t d tool. 1lm1ltr to a J c a l p tl. lhll provrdu greater control over lht operation and htnce gruter preci11on
11111 i!Jfot l.ll (lft•t •HJlltHii rr�u,r 1J• t . r : •·n ltJ prt•vt•ttl pt.uu·�� .wd r••qiJirt• l llt1 H•ftltiltl.tn 1 0 r•tt•rt ltl''f' fl'''''
t titom from IJV�<rh.., 1llrl., whit 1 t •HI o�11t111r 111• cJit•� ,urt• Ill pr1•vt•ru rQuruJin� tJI prt•pt�r.ttlon (Ortwr',
pl •1.tlc nnd t·tt-tl dt•tmrn t ht•ru crrw. "' ,., '""' Ill H,J
nrrt • •• �'""' p11111un ''' lh• KIIIKIV•l , ,, , '""'" l lu• .rpptll ' '' ''"' " ' .r ' ·'Y' I of h.rrtlerrlnH l.r«[tJI• r
'""'''"'''' wlrh lh� '' '' " •,tropt•tl hou, lire ll'llrrrltl •ill (M.rr�tdur, ll••llt"r fJt•lll.il) l tJ pl.r•,r••r <I I•"• •,e,JI� tht•
Jllllt"""� lllh " •,lrtrrr ty)lrlllrlt.;l '" ' "' """ ' hur .,urft�n� pom•,fly r1tl t rt• d l l"• .J l l. t rd�� r, mQrr• o•-.l1, !.tnt .. . nd br.1�lon. r�prcl lly on thr rdg s. casts ar after laboratoy procedur s and the presence of only
(H t<,fl 11111 '"''· I ll '''' 1, KrJin<·ll ""'' ' " ' ' hy rtw .ru , ur f.;c t• wlillOIII .rdtiiiiR Ulllfr••olrr•tl lhlrknl"o'• rh,rl rJ�tly da m, grd during laboratory procrdu rrs . Whrn a f w Incidental marks attest to the expet care and
1 11111 <•IIH�·.,It lor 'llrlllflnH r he "lllkiK•ntt• [Jill tOiild ( (Jflirrmnl·.t· rllll�llflr ( ,1',1 rt•plll .t-, U lw. 1) 1 / v l rwr• d undrr magnlncallon. comparing the damag precision or the d ntal t chnlclan.
Nl•. '''·" l lr• lnrl'� '•'""' l i p ''"''w . lr ' '' M�<l v"rY ""·" ' " " ' 10 JH) If 1111• 1•1"1"''' 1 •, . r pp t iN I corrrr rly, .rdrlillR t mm r d l, rrly following prrp�mtlon or rhr finish lin Wirh t h use of polyur than or poxy resin, which
llr• flrri.h " ' "' wllluull ror•rrlnK lr l trh '"' ' "'''"'"• nn llllr kn�t-, t, , 1 1 11• rll•�,, will l 1 11vr <�n U f MfiiJr ',w(.iff' d. "• on a plaorrr dlr (srr nR 10·17) and tarcr. after dlff r slgnlficanrly f ro m plast r In terms of resistance
th• ltl•nl ••<t•·rr�llin o( l i rA '''"''' � 1 1 111 1 11rt• , ,,,, ,, , "' wtwn IIIIJinliKhly dr y: d , t r ln y •,wf.w• lnrllc.tll'o .1rltiNI all 1, 1 b o ra ro ry procNJurrs arr compl tr (rigs 10-29 prop rt l s. lncld ntal marks from the laboratory pro·
11• llrrl�r llrr•'"·" CIIH 111 1•1) r lrlr <nr•'••· ,1ncl 10 JO). th<• rxtrn�lvr wrar and marking thai cedur s re virtually non xlstent. making the opera·
ltnf �tiJ'Jf1 plll', tt1r h, i '• poor nu�f·,l!ln(r tu t r11-1lon cour ,• ot I bor tory proc dur s
llrrtlt•t liiHII fii>IHII IIIr .;tltlll, lhr lt•tlrrrld.orr t •Ill ow�r� durl•l» th tor's lob mor practical and less stressful (Fl gs 10·)1
lrolfll1•1� I""' I,IIHI l1y lllllrrrriiiH rlrt• [IIIJfll• or pit .rl 1<1 .rnd r rlfilpH"•'oiOII olllll )', l l u•H•f<lll' '•IJhjrt l Ill frMIIIfl' .. br om<"• rvldrnt. Thrrrforr, thr lntegrlly of t h r die to 10 3)). .
m
I hi· fltll',lt IH,i· llllh •I 11•·11 ·.il.rrpt·flt·d Hl',lttJrt••·ul ·.lfll
11.11 Ill ,J
•,t olltJf'l l i l , Jli J tJ
lf·i llfiS I H''(MtHt t)uf tuu' IIIS t .;•,t , l t u• lt•t h f l l t l.m Jit••t I',IIHJ 1·. �··,•,,. , , , , , , 1 I(Jr .;lf,jJJI.,I It;lt ,, , Uw , , ..,
I •I (ifi'P·H•· IHW. h II lito oil f t••,•, IJ·,u·� ·.p�·t "' ' di.JirttHJtl I'H·illtHI "'·H.Ifl , .wtf t tJr rH t .;pit oil t. tJrtltJIH'• t;l tiH·
iHW� jMh•tllt'fi b t tllii •HJIIIIJI'II �� 1 '11J t}/tJ .uuj l�11 IJI,tJ, t ft1lltl'• •itt• t·JI•t ut1•d llll h dtUt•tl·ttl fltii•At lltu·•,
(tJifjt•tJ IIJ-11 W,<d 111 lt,l '•IJH•tl, I ll•• Jw·, ,,,, {J I JIItlidl ,;tf,iiJI .illtltl ltlf f i 'JIfl ' h (JIJ',',Ibh• lll l h
. IKfltotl ltJ f•lrl'' '' •,tJIIIto .lflKit,, tm t lw pl.1';1i•r tH

d •· • f•lltt•• r ml'f,; l tJt C f•f,iflllt u••�ttJfoiWJII trl •H.Ifl'• • ptt}/llf
,•,, ,, , ,,Jt, ,..,.,;1111� lh•· lltll.,h llru .;ud t l u• ptulitm •·d t t w r •· ,Jt•• , , , t w.,t•• t•·tllt ,,, .;wl tUJrj/tHrt.;l .w.;
IJf III I(Hf"IJM<d ltJIJIIi l t iJI I Utto •11Jll dl It; 111•11 litH• ltJitlll I IJIIIIJIJf', (11• , tJi•ltJid tJf hiHI/CJIIt.;( ,ifld/tH ll'f
Ht•t oJIJ•,t• lut (j,Y IJf flloHt l flS llt� "' '' 'K i t l .wd t i t• HI,. l lt ,;l t;ll'f .wd ';IJl;t t)flllJUf',) (f j�'; 1J IJ ,J rUJ 1J I JJ.
I IJifl l ifiHfll',ltl� thto (lft< i i "JIIHJ IJf liu• dt•fltllll/t' tt·•lltHoi I IH IMffl,;l t H111t1 !lf••p.;r,,wm·�. tht• dt••,l1 tJf Htr•
IJtJII 11 l lJU"ildt•(l;tJif•, lflr• oHJihtH'o (t'I OHiflli•lld J'.IfiJS ,j fhtJ•.t• I tnt• J•, ltti'MHI.H, ·t.;rVhiM .rt t tJfdtn� to tiJt• pl.;nc••,
llllt r,tiJ[W ll lg 111 Il) .uuJ �··tJffi H r y of lht• jlfl·p.lr.Hicm , ,111d u•q ul rt· •, go'·'''''
f /�II fiiJr�irrg dl ltl�lt Hr•I,IIIfll .t!IIJII , 1 1 • lt•d lll[l r,m t tHit f•tJlf,,lltHI IJy I t!'' dr•ut.;l fl•tllnid.lfl. l h•• pn•pM.J
ilii rw�d 111 ' "''"'·" ·•i'l""""·"'' '' "" trlgtr qu.illlt ln tlcm ftH pdrtldl c r tJ WI I 'l mu•A tw dt·VtJid ol undr•rc ur•,
•,t HJifltlfll� Ill prrtrul r•tttJf f rtJfrl tilt� vl tu .H I II t;l •HI .wd tH 1!,,,,. ,Jdt•qu,,lt• rt•tt•lllltHI', lc�r lh• XtJid
uw.uii,J!Jit� l1tJf f1 rt'HIO/to @ l i �I V.i fflHrl t h •" t.J•,t, ttu r• .. ,ttJt,JIItm Cwltit h c.w oltt•f! br• thr• w.rtl•, , htJYt••, ,
l �<tllllltl•l tl IJtoKIW. wUii ,, f 'J i tihiint•t••r mu11d ,ifll[ �IIJIIYI", tJf 1 ) 11• [lll'[l •lr•llirII fl ',t•tfJ (f iR 10 111)
'"''"''""' tmr C!•Jr .'•',o), " '"' h h ·.urr.ohl•· I•JI ''''tl' 111t1 '' '" ' ' ""' '' ' " pill'. , wlr l ll ·,)ltHJid r••m.1tn lnr.ll t In
p l •1f l t• r •Jtld t-ptul r-�Au wtwn u•.�ltl{ •I I 'J , tJt;tJ rpru
"''' ''"''"''" Cf ig 111 I'll Mrlllrr� •'"'"''' "" '"' '' " v••ry lhlriH llu· rrrii iiJ'•"'P''• lht• lt•t hlllt l.rn m.rrk� rt11• fog 10 18 Rou11ne un at megnlllctlton tllowl ltchniCIInl r o 1m pro•• lhlir qutlrtatr•• 1tandards Note the ergonomiC posture ol the operator.
f1g 10 19 Roughtng out the muter cu r lntllllly. lht g1ng•u reproductd In pluter Is tlom1na1td under magn1f1ut1on w1th 1 ball d11mond bur
,,,.,,, ,,, ..,.(, P•Htlt IJI.trll (I !I ,,,,jjfl•f t ,, •• , llhl•(l• ptJlH tl m i r tJf llu· [tr••rw.rlltJrr w.lng .r "IIIJr••tl p••rr<ll. l h••
with the utm01t cere l l k t n r o IV Old sccrdonlllly d a m s g • n g the d11 F1g 10-20 A fter lhe f i ( S I tllge. the techn1mn cont1nuu With a cylindrical
rt-'.ht.Ht t to ltJ ,1JJf,t�lrm .md l �l lth •nt ; ltJ •,ptJnr,•r rno�Yt••, prt•p,or.rriiJII lhrrl! •, fill I IHII p lt• rt• liJWfl', ftJtiOW .r rPK dltmond bur thll ls tbout l 5 mm long tnd hu a t1pered stsm to priVtnt lntdverttnt contact With the f1nlsh line Th11 bur 18350 Komett per
mill the ltchnlcltn to con1truct the rtdlcultr profile t pi c t l l y. by gelling cion to the l1nl1h ltnt w l t hou r runnrng the risk of damag�ng it
II '" ' 1 •·•'• / rn muntl 1111 ''"�'"• I "'"Y '" " ' pt�ly ui.H, t tiii�I•HII UJUf'1l• Orl l ilt• '••Hill' p{,if1(', whitt• lWi11 frg 10 71 Prepmtion ot lhl die prairie The reproduction of the tru tplul to the iln11h tine 11 11n11hed manually under h1gh magnilicat1on
tHt•l lt.wto ,,.�.tn t •�'• ' ) t;tft•t S''"•if � r Wl•.ff rt·�l�tt•nu �. fm p.lll l.r l 1 r tJW f l', "'' lrrt•grrl.tr .rnd on dllf••rt•rll
wirh a we t i - eh tr pen t d tool. 1lm1ltr to a J c a l p tl. lhll provrdu greater control over lht operation and htnce gruter preci11on
11111 i!Jfot l.ll (lft•t •HJlltHii rr�u,r 1J• t . r : •·n ltJ prt•vt•ttl pt.uu·�� .wd r••qiJirt• l llt1 H•ftltiltl.tn 1 0 r•tt•rt ltl''f' fl'''''
t titom from IJV�<rh.., 1llrl., whit 1 t •HI o�11t111r 111• cJit•� ,urt• Ill pr1•vt•ru rQuruJin� tJI prt•pt�r.ttlon (Ortwr',
pl •1.tlc nnd t·tt-tl dt•tmrn t ht•ru crrw. "' ,., '""' Ill H,J
nrrt • •• �'""' p11111un ''' lh• KIIIKIV•l , ,, , '""'" l lu• .rpptll ' '' ''"' " ' .r ' ·'Y' I of h.rrtlerrlnH l.r«[tJI• r
'""'''"'''' wlrh lh� '' '' " •,tropt•tl hou, lire ll'llrrrltl •ill (M.rr�tdur, ll••llt"r fJt•lll.il) l tJ pl.r•,r••r <I I•"• •,e,JI� tht•
Jllllt"""� lllh " •,lrtrrr ty)lrlllrlt.;l '" ' "' """ ' hur .,urft�n� pom•,fly r1tl t rt• d l l"• .J l l. t rd�� r, mQrr• o•-.l1, !.tnt .. . nd br.1�lon. r�prcl lly on thr rdg s. casts ar after laboratoy procedur s and the presence of only
(H t<,fl 11111 '"''· I ll '''' 1, KrJin<·ll ""'' ' " ' ' hy rtw .ru , ur f.;c t• wlillOIII .rdtiiiiR Ulllfr••olrr•tl lhlrknl"o'• rh,rl rJ�tly da m, grd during laboratory procrdu rrs . Whrn a f w Incidental marks attest to the expet care and
1 11111 <•IIH�·.,It lor 'llrlllflnH r he "lllkiK•ntt• [Jill tOiild ( (Jflirrmnl·.t· rllll�llflr ( ,1',1 rt•plll .t-, U lw. 1) 1 / v l rwr• d undrr magnlncallon. comparing the damag precision or the d ntal t chnlclan.
Nl•. '''·" l lr• lnrl'� '•'""' l i p ''"''w . lr ' '' M�<l v"rY ""·" ' " " ' 10 JH) If 1111• 1•1"1"''' 1 •, . r pp t iN I corrrr rly, .rdrlillR t mm r d l, rrly following prrp�mtlon or rhr finish lin Wirh t h use of polyur than or poxy resin, which
llr• flrri.h " ' "' wllluull ror•rrlnK lr l trh '"' ' "'''"'"• nn llllr kn�t-, t, , 1 1 11• rll•�,, will l 1 11vr <�n U f MfiiJr ',w(.iff' d. "• on a plaorrr dlr (srr nR 10·17) and tarcr. after dlff r slgnlficanrly f ro m plast r In terms of resistance
th• ltl•nl ••<t•·rr�llin o( l i rA '''"''' � 1 1 111 1 11rt• , ,,,, ,, , "' wtwn IIIIJinliKhly dr y: d , t r ln y •,wf.w• lnrllc.tll'o .1rltiNI all 1, 1 b o ra ro ry procNJurrs arr compl tr (rigs 10-29 prop rt l s. lncld ntal marks from the laboratory pro·
11• llrrl�r llrr•'"·" CIIH 111 1•1) r lrlr <nr•'••· ,1ncl 10 JO). th<• rxtrn�lvr wrar and marking thai cedur s re virtually non xlstent. making the opera·
ltnf �tiJ'Jf1 plll', tt1r h, i '• poor nu�f·,l!ln(r tu t r11-1lon cour ,• ot I bor tory proc dur s
llrrtlt•t liiHII fii>IHII IIIr .;tltlll, lhr lt•tlrrrld.orr t •Ill ow�r� durl•l» th tor's lob mor practical and less stressful (Fl gs 10·)1
lrolfll1•1� I""' I,IIHI l1y lllllrrrriiiH rlrt• [IIIJfll• or pit .rl 1<1 .rnd r rlfilpH"•'oiOII olllll )', l l u•H•f<lll' '•IJhjrt l Ill frMIIIfl' .. br om<"• rvldrnt. Thrrrforr, thr lntegrlly of t h r die to 10 3)). .
m
rHAPHR 1 0
Laboratoy Procedures ]
FIG 10·23 FIG 10-29 FIG 10-30
FIG 10·31
FII IG-27 FIG 1 0 28 FIG 10-33
F1gs 10-22 and 10-23 Two definltiYO cermet crowns. Note the two types of margin closure. Fig 10-22 shows a crown with a buccal closure In F1g 10-29 After casting. the gold partial crown is seated. checked. and adapted on the working cast. Fig 10-30 Although the greatest care has
ceramic and a pala.tal closure in . metal. while Fig 1 0-23 shows a marginal closure with a 360-degree metal border. I n both cases the con been taken. the plaster die shows clear signs of deterioration after completing all the laboratory procedures. Including casting. F1g 10-31 1dentical
tour of the crowns 1.s perfectly aligned w1th tha emergenc e profile • . with respect for biologic principles. Fig 10-24 Natural tooth extracted and die cast In polyurethane resin. Even after completion of the laboratory procedures. all of the preparation details are Intact. Fig 10-32 Partial
.
prep � red Hor teach1ng purpos es) for a gold rutoratlo � . w1th a partlal . crown. The partial crown for this preparation leaves no room for com crown on natural tooth shows excellent margin adaptation. the essential prerequisite in restorations of this type. Fig 10-33 Restoration on a
promln. s1nca 111 geometr � .11 essen ! 1al to tha .stability and retentiOn of the restoration. Figs 10-25 and 10-26 The preparation mar g in is lateral sector using partial crowns. The good marginal closure altar cementation. combined with perfect harmony with tooth anatomy, maku
marked With a colo � ed penc1l by eurhng very slight pressure: harder pressure could round off the angie of the preparation. Figs 10- 27 and this restoration attractive despite its esthetic limitations.
10-28 When • cut 1s developed 1n ptuter. the llchnlmn should apply a hardening liquid. which penetrates the pores of the plaster and
makes 11 more rts1slant dunng the laboratory procedures
rHAPHR 1 0
Laboratoy Procedures ]
FIG 10·23 FIG 10-29 FIG 10-30
FIG 10·31
FII IG-27 FIG 1 0 28 FIG 10-33
F1gs 10-22 and 10-23 Two definltiYO cermet crowns. Note the two types of margin closure. Fig 10-22 shows a crown with a buccal closure In F1g 10-29 After casting. the gold partial crown is seated. checked. and adapted on the working cast. Fig 10-30 Although the greatest care has
ceramic and a pala.tal closure in . metal. while Fig 1 0-23 shows a marginal closure with a 360-degree metal border. I n both cases the con been taken. the plaster die shows clear signs of deterioration after completing all the laboratory procedures. Including casting. F1g 10-31 1dentical
tour of the crowns 1.s perfectly aligned w1th tha emergenc e profile • . with respect for biologic principles. Fig 10-24 Natural tooth extracted and die cast In polyurethane resin. Even after completion of the laboratory procedures. all of the preparation details are Intact. Fig 10-32 Partial
.
prep � red Hor teach1ng purpos es) for a gold rutoratlo � . w1th a partlal . crown. The partial crown for this preparation leaves no room for com crown on natural tooth shows excellent margin adaptation. the essential prerequisite in restorations of this type. Fig 10-33 Restoration on a
promln. s1nca 111 geometr � .11 essen ! 1al to tha .stability and retentiOn of the restoration. Figs 10-25 and 10-26 The preparation mar g in is lateral sector using partial crowns. The good marginal closure altar cementation. combined with perfect harmony with tooth anatomy, maku
marked With a colo � ed penc1l by eurhng very slight pressure: harder pressure could round off the angie of the preparation. Figs 10- 27 and this restoration attractive despite its esthetic limitations.
10-28 When • cut 1s developed 1n ptuter. the llchnlmn should apply a hardening liquid. which penetrates the pores of the plaster and
makes 11 more rts1slant dunng the laboratory procedures
CHAPTER 1 0
Laboratory Procedures J
..CREATION O F THE WAX PATIERN The technician must know the physical properties . shorter bristles and applying a slight rubbing move· semi-hard wax (Inlay Wax Violet, GC) is applied only
of wax to handle it well; as with all materials, a ment to facilitate spreading. 10 at the cervical margin, where the greatest degree of
change in physical state is accompanied by a change Use of an electric spatula to apply wax to the die precision is needed to develop details (Fig 10-37).
Using wax i n precision work
in volume that depends on temperature and chemi· has completely replaced the method of heating a For the third layer, a hard wax (Creative, Kerr Hawe)
Making a wax pattern, whether for a single unit or a cal structure.'8·'9 Dental waxes are amorphous sub· traditional spatula directly over the flame of a is applied (Fig 10-38), protecting the inner layer from
fixed partial denture, is the most delicate step in stances without a cystalline structure and therefore Bunsen burner (Fig 10-36). The temperature of the the risk of deformation during removal of the wax pat
preparing a restoration; any imperfection created in are extremely delicate. They have a high thermal electric spatula can be easily regulated to keep var tern from the die and lending it additional stability.
the wax is transferred to the metal structure with no expansion coefficient and variable stability at differ· ious waxes, used for diferent purposes, from over· Layering the three types of wax in a definitive
possibility of correction. Therefore, sufficient experi· ent temperatures; expansion of up to 0.7% can heating. Lack of temperature control often leads to pattern for the restoration allows for careful manage·
ence, a good technique, and in-depth understanding accompany a temperature rise of 20°C, while a con· evaporation of some of the material and changes in ment of the esthetics of the axial profiles and occlusal
of the material are all equally indispensable. traction of 0.35°/o is common with cooling from 37°C wax composition and characteristics.'0 morphology (Fig 10·39) and results i n optimal adher·
to 25°C.'9 The contraction that occurs while wax is Melted wax is applied to the die in small quanti· ence of the wax to the die and equally optimal defor
cooling can create inner tensions and lead to inac ties to obtain better surface reproduction and re· mation resistance during removal.'0•16 Precision work
Wax material
curacies in the wax pattern once the cooling process duce contraction of the wax as it cools. When the is evident in the parasagittal area of the wax pattern
Because wax has a wide variety of applications in is complete. Tensions during cooling largely depend first wax layer is applied, the temperature of the die of the partial crown shown in Fig 10-40: the inner
dentistry, a large assortment of special waxes is avail· on dramatic differences in temperature. For example, should be slightly above body temperature (ie, 37°C layer faithfully reproduces the design of the die prep·
able. Wax is indispensable for its plasticity, shine, if hot wax is dripped onto a cold surface, it will solid· to 38°C). aration without evident contractions or distortions.
adhesiveness, and resistance (to water, air, and light), iy too quickly because the abrupt change in ten· Such precision is a prerequisite for successful casting.
as well as its role in casting with the lost-wax tech perature does not allow enough time for the wax to To create a cermet framework for a metal-ceramic
Wax pattern construction
nique. However, preparing a pattern with such deli· dissipate the physical stress. The result is that the crown, the technician must develop the entire anato·
cate material requires great skill. wax will detach from the support and deform. There· Wax is applied with a thin, tapered point (eg, PKT my of the tooth in wax (Fig 10-41). A subtraction tech·
The waxes most commonly used in the dental lab· fore, wax should be handled at a fairly low temper· no. 2, Dentsply) that requires the operator to use nique is used to determine, with a reasonable degree
oratory are compounds, primarily of natural waxes, ature (ie, 50°C to 55°C). 18 small amounts, thus preventing the formation of air of precision, the quantity of wax to remove for the
modified natural waxes, and semisynthetic or syn bubbles and achieving maximum adherence to the ceramic covering. To create a wax structure that
thetic waxes. To these are generally added resins•B die. Three types of wax with distinct characteristics reproduces an esthetic and functional substrate for
Modeling techniques
that increase their resistance, plasticity, hardness, and are used. supporting the ceramic veneer, one of two methods
adhesiveness. In general, alkane and parain waxes The dental technician must apply a lacquer and an The first layer is created with a soft wax (Siaycris can be adopted. The first method is to progressively
are long-chain hydrocarbons that have had diferent Wax, Dentsply) that has a low melting point (about carve the wax, using specially designed instruments
isolator to the dies before the wax pattern can be
elements added through a chemical process to obtain constructed. Spacer lacquer is applied with a fine 50°(). In the removal phase, this soft layer mini· (Fig 10-42) to control wax removal and leave enough
speciic physical characteristics. Classification criteria tipped brush (to control thickness) over the entire mizes microdistortions of the wax pattern and makes space for ceramic layering (Figs 10-43 to 10-45). The
for waxes used in dentistry take into particular con die except the cervical margin (Fig 10·34), where the it more smooth, especially on complete crown prep· other method uses the cast to create a silicone index
sideration the material's hardness and fluidity. die spacer provides room for cement application arations or special preparations like those of partial that is vertically sectioned to monitor the amount of
Liposoluble or pigment-based colorants are added crowns, which are not very smooth. wax that is removed (Figs 10·46 and 10-47).
between it and the crown.
to distinguish between various wax types with dif The second layer is made with a semi-hard wax, This approach to constructing the framework guar·
The isolator must be compatible with both the wax
ferent characteristics. For constructing fixed partial the main characteristics of which are minimal volu· antees precision in critical zones where occlusal forces
and spacer lacquer. A soft-bristle brush (Fig 10-35) is
dentures and crowns, contrasting colors are used to metric contraction, excellent thermal and dimension are concentrated (Figs 10-48 and 10-49) and guar
used to apply the isolator to the plaster die. Epoxy
highlight surface contours or special areas of the al stability, and greater resistance to microdistor· antees suficient space, with respect to anatomic
resin dies have a smooth water-repellent surface that
restoration. lions during detachment from the die surface. The parameters, for subsequent ceramic veneering.
can be covered more eficiently using a brush with ..
26 327
CHAPTER 1 0
Laboratory Procedures J
..CREATION O F THE WAX PATIERN The technician must know the physical properties . shorter bristles and applying a slight rubbing move· semi-hard wax (Inlay Wax Violet, GC) is applied only
of wax to handle it well; as with all materials, a ment to facilitate spreading. 10 at the cervical margin, where the greatest degree of
change in physical state is accompanied by a change Use of an electric spatula to apply wax to the die precision is needed to develop details (Fig 10-37).
Using wax i n precision work
in volume that depends on temperature and chemi· has completely replaced the method of heating a For the third layer, a hard wax (Creative, Kerr Hawe)
Making a wax pattern, whether for a single unit or a cal structure.'8·'9 Dental waxes are amorphous sub· traditional spatula directly over the flame of a is applied (Fig 10-38), protecting the inner layer from
fixed partial denture, is the most delicate step in stances without a cystalline structure and therefore Bunsen burner (Fig 10-36). The temperature of the the risk of deformation during removal of the wax pat
preparing a restoration; any imperfection created in are extremely delicate. They have a high thermal electric spatula can be easily regulated to keep var tern from the die and lending it additional stability.
the wax is transferred to the metal structure with no expansion coefficient and variable stability at differ· ious waxes, used for diferent purposes, from over· Layering the three types of wax in a definitive
possibility of correction. Therefore, sufficient experi· ent temperatures; expansion of up to 0.7% can heating. Lack of temperature control often leads to pattern for the restoration allows for careful manage·
ence, a good technique, and in-depth understanding accompany a temperature rise of 20°C, while a con· evaporation of some of the material and changes in ment of the esthetics of the axial profiles and occlusal
of the material are all equally indispensable. traction of 0.35°/o is common with cooling from 37°C wax composition and characteristics.'0 morphology (Fig 10·39) and results i n optimal adher·
to 25°C.'9 The contraction that occurs while wax is Melted wax is applied to the die in small quanti· ence of the wax to the die and equally optimal defor
cooling can create inner tensions and lead to inac ties to obtain better surface reproduction and re· mation resistance during removal.'0•16 Precision work
Wax material
curacies in the wax pattern once the cooling process duce contraction of the wax as it cools. When the is evident in the parasagittal area of the wax pattern
Because wax has a wide variety of applications in is complete. Tensions during cooling largely depend first wax layer is applied, the temperature of the die of the partial crown shown in Fig 10-40: the inner
dentistry, a large assortment of special waxes is avail· on dramatic differences in temperature. For example, should be slightly above body temperature (ie, 37°C layer faithfully reproduces the design of the die prep·
able. Wax is indispensable for its plasticity, shine, if hot wax is dripped onto a cold surface, it will solid· to 38°C). aration without evident contractions or distortions.
adhesiveness, and resistance (to water, air, and light), iy too quickly because the abrupt change in ten· Such precision is a prerequisite for successful casting.
as well as its role in casting with the lost-wax tech perature does not allow enough time for the wax to To create a cermet framework for a metal-ceramic
Wax pattern construction
nique. However, preparing a pattern with such deli· dissipate the physical stress. The result is that the crown, the technician must develop the entire anato·
cate material requires great skill. wax will detach from the support and deform. There· Wax is applied with a thin, tapered point (eg, PKT my of the tooth in wax (Fig 10-41). A subtraction tech·
The waxes most commonly used in the dental lab· fore, wax should be handled at a fairly low temper· no. 2, Dentsply) that requires the operator to use nique is used to determine, with a reasonable degree
oratory are compounds, primarily of natural waxes, ature (ie, 50°C to 55°C). 18 small amounts, thus preventing the formation of air of precision, the quantity of wax to remove for the
modified natural waxes, and semisynthetic or syn bubbles and achieving maximum adherence to the ceramic covering. To create a wax structure that
thetic waxes. To these are generally added resins•B die. Three types of wax with distinct characteristics reproduces an esthetic and functional substrate for
Modeling techniques
that increase their resistance, plasticity, hardness, and are used. supporting the ceramic veneer, one of two methods
adhesiveness. In general, alkane and parain waxes The dental technician must apply a lacquer and an The first layer is created with a soft wax (Siaycris can be adopted. The first method is to progressively
are long-chain hydrocarbons that have had diferent Wax, Dentsply) that has a low melting point (about carve the wax, using specially designed instruments
isolator to the dies before the wax pattern can be
elements added through a chemical process to obtain constructed. Spacer lacquer is applied with a fine 50°(). In the removal phase, this soft layer mini· (Fig 10-42) to control wax removal and leave enough
speciic physical characteristics. Classification criteria tipped brush (to control thickness) over the entire mizes microdistortions of the wax pattern and makes space for ceramic layering (Figs 10-43 to 10-45). The
for waxes used in dentistry take into particular con die except the cervical margin (Fig 10·34), where the it more smooth, especially on complete crown prep· other method uses the cast to create a silicone index
sideration the material's hardness and fluidity. die spacer provides room for cement application arations or special preparations like those of partial that is vertically sectioned to monitor the amount of
Liposoluble or pigment-based colorants are added crowns, which are not very smooth. wax that is removed (Figs 10·46 and 10-47).
between it and the crown.
to distinguish between various wax types with dif The second layer is made with a semi-hard wax, This approach to constructing the framework guar·
The isolator must be compatible with both the wax
ferent characteristics. For constructing fixed partial the main characteristics of which are minimal volu· antees precision in critical zones where occlusal forces
and spacer lacquer. A soft-bristle brush (Fig 10-35) is
dentures and crowns, contrasting colors are used to metric contraction, excellent thermal and dimension are concentrated (Figs 10-48 and 10-49) and guar
used to apply the isolator to the plaster die. Epoxy
highlight surface contours or special areas of the al stability, and greater resistance to microdistor· antees suficient space, with respect to anatomic
resin dies have a smooth water-repellent surface that
restoration. lions during detachment from the die surface. The parameters, for subsequent ceramic veneering.
can be covered more eficiently using a brush with ..
26 327
CHAPTER 1 0
� For burnishing the wax at the cevical margin, the plifies laboratory procedures and reduces the risk of
authors use a Le Cron-type instrument that has microtensions during removal and errors that appear
been modified to provide a slightly curved shape on only after casting. The surface of the wax must be
one side and a rounded outline. The tip of the extremely smooth and devoid of microgrooves,
instrument is heated to soften the wax and then which can be verified only under high magnification,
placed on the extension apical to the finish line, to prevent mechanical pressure from being exerted FIG 1 0-34 FIG 10-35
thus creating a coping whose initial shape is guided in the metal polishing stage that could lead to the
by the emergence proile (Fig 10-sol. Using a metal creation of crown subcontours (Fig 10-53).
instrument with a modified tip (Figs 10-51 and 10-52) When imperfections or errors i n the wax pattern
and working at high magnification, the technician are corrected without delay, before casting, the tech
must remove all excess wax apical to the finish line. nician not only saves time but obtains more pre-
When this maneuver is correctly performed, it sim- dictable outcomes and h igher-quality prosthetics. ..
FIG 10-36 FIG 10-37
FIG 1 0-38 FIG 10-39

Fig 10-4 Application of spacer lacquer. using a fine-tipped brush. to leave the space for cementalion. This controls thickness
on lhe different parts of the die. excepl for the margin area.
Fig 10-35 Using a soft-bristled brush. the plasler die is coated with a thin layer of isolator thai is compatible with both the wax
and the spacer lacquer.
Fig 10-36 o 10-38 Creation of the wax pallern. Melted wax is applied to the die in small amounls to obtain a beller reproduction
of the dies surface and reduce the conlraction of the wax itself. Using an eleclric spatula makes it possible to control the tem
perature. thus preventing the wax from overhealing. The traditional Bunsen burner method often overheats the wax. which
causes some evaporation and modification of wax composition.
ig 10-39 Wax molar modeled into its final esthetic and functional form. The wax material was built up lo construct both the
axial profiles and the occlusal morphology.
m
CHAPTER 1 0
� For burnishing the wax at the cevical margin, the plifies laboratory procedures and reduces the risk of
authors use a Le Cron-type instrument that has microtensions during removal and errors that appear
been modified to provide a slightly curved shape on only after casting. The surface of the wax must be
one side and a rounded outline. The tip of the extremely smooth and devoid of microgrooves,
instrument is heated to soften the wax and then which can be verified only under high magnification,
placed on the extension apical to the finish line, to prevent mechanical pressure from being exerted FIG 1 0-34 FIG 10-35
thus creating a coping whose initial shape is guided in the metal polishing stage that could lead to the
by the emergence proile (Fig 10-sol. Using a metal creation of crown subcontours (Fig 10-53).
instrument with a modified tip (Figs 10-51 and 10-52) When imperfections or errors i n the wax pattern
and working at high magnification, the technician are corrected without delay, before casting, the tech
must remove all excess wax apical to the finish line. nician not only saves time but obtains more pre-
When this maneuver is correctly performed, it sim- dictable outcomes and h igher-quality prosthetics. ..
FIG 10-36 FIG 10-37
FIG 1 0-38 FIG 10-39

Fig 10-4 Application of spacer lacquer. using a fine-tipped brush. to leave the space for cementalion. This controls thickness
on lhe different parts of the die. excepl for the margin area.
Fig 10-35 Using a soft-bristled brush. the plasler die is coated with a thin layer of isolator thai is compatible with both the wax
and the spacer lacquer.
Fig 10-36 o 10-38 Creation of the wax pallern. Melted wax is applied to the die in small amounls to obtain a beller reproduction
of the dies surface and reduce the conlraction of the wax itself. Using an eleclric spatula makes it possible to control the tem
perature. thus preventing the wax from overhealing. The traditional Bunsen burner method often overheats the wax. which
causes some evaporation and modification of wax composition.
ig 10-39 Wax molar modeled into its final esthetic and functional form. The wax material was built up lo construct both the
axial profiles and the occlusal morphology.
m
Fig 10-40 Sectioned wax pattern on the die. Different types of wax were used for an excellent adaptation of the wax pattern to the inner sur
face of the prepared die. Fig 10-41 Wax pattern of a three-unit fixed partial denture. Note the definition of the marginal collar to support the
ceramic veneer. Fig 10-42 Tool for gauging the depth of wax to be removed to make room for the ceramic veneer. developed by G. Furno. Figs
10-43 and 10-44 Use of tool during wax reduction on different parts of the pattern. The technician can control the amount of wax removed on
the basis of the volumetric space that is needed. Fig 10-45 With a spoon-shaped tool. the technician defines the support collar for the ceram
i c veneer. creating a line of definition between metal and ceramic. Figs 10-45 and 10-47 Once cut sagittally. the silicone index created on the
wax pattern prior to wax removal makes it possible to monitor the removal. This space will be entirely occupied by the esthetic ceramic
materials. Figs 10-49 and 10-4g Connection zones designed for a weld to guarantee sturdiness and stress resistance, the surface area of the
connection zones must never be less than 2.5 mm2. Fig 10-50 Finishing the contour. following the anatomic profile of the tooth. The tip of the
tool is heated to soften the wax and placed on the extension apical to the finish line to create a coping guided by the radicular emergence
profile. Fig 10-51 With a pointed instrument. excess wax apical to the finish line is carefully eliminated. This procedure reduces the risk of
creat1ng microtensions in removal of the wax pattern that could provoke errors visible only after casting. F1g 10-52 Using the same spoon
shaped instrument. the marginal collar is defined. Fig 10-53 Following these procedures. the surface of the wax contour of the crown is
extremely smooth. Developing the wax pattern carefully. without postponing the correction of any errors until after casting. saves time and
prov1des better resulls.
0 331
Fig 10-40 Sectioned wax pattern on the die. Different types of wax were used for an excellent adaptation of the wax pattern to the inner sur
face of the prepared die. Fig 10-41 Wax pattern of a three-unit fixed partial denture. Note the definition of the marginal collar to support the
ceramic veneer. Fig 10-42 Tool for gauging the depth of wax to be removed to make room for the ceramic veneer. developed by G. Furno. Figs
10-43 and 10-44 Use of tool during wax reduction on different parts of the pattern. The technician can control the amount of wax removed on
the basis of the volumetric space that is needed. Fig 10-45 With a spoon-shaped tool. the technician defines the support collar for the ceram
i c veneer. creating a line of definition between metal and ceramic. Figs 10-45 and 10-47 Once cut sagittally. the silicone index created on the
wax pattern prior to wax removal makes it possible to monitor the removal. This space will be entirely occupied by the esthetic ceramic
materials. Figs 10-49 and 10-4g Connection zones designed for a weld to guarantee sturdiness and stress resistance, the surface area of the
connection zones must never be less than 2.5 mm2. Fig 10-50 Finishing the contour. following the anatomic profile of the tooth. The tip of the
tool is heated to soften the wax and placed on the extension apical to the finish line to create a coping guided by the radicular emergence
profile. Fig 10-51 With a pointed instrument. excess wax apical to the finish line is carefully eliminated. This procedure reduces the risk of
creat1ng microtensions in removal of the wax pattern that could provoke errors visible only after casting. F1g 10-52 Using the same spoon
shaped instrument. the marginal collar is defined. Fig 10-53 Following these procedures. the surface of the wax contour of the crown is
extremely smooth. Developing the wax pattern carefully. without postponing the correction of any errors until after casting. saves time and
prov1des better resulls.
0 331
CHAPTER 1 0
.. Removal technique a n d preparation for CASTI N G

cast i n g
Investi n g proce dure
Successful removal o f t h e wax pattern from t h e die
is crucial to the preservation of accuracy achieved in The wax pattern is surrounded by refractory invest·
all previous prosthetic phases, especially when the ment for precision casting in gold alloy using the
procedure concerns several connected restorations. lost-wax technique. Investing must be performed
In removing the wax pattern, the operator must with extreme care and within 10 minutes of remov
assume a correct and confident hand position with ing the wax pattern from the die to minimize wax FIG 10-54 FIG 10-55
suficient elbow support to minimize the natural deformation from exposure to the surrounding con
tremor that could jeopardize precision'0·1 1 (Figs 10-54 ditions. Phosphate-bonded casting investments" have
and 10-55). The use of rubber dam improves the oper replaced those with a gypsum base because of the
ator's hold on the wax pattern, and exerting pressure higher melting temperatures of gold alloys.10 A cast
with opposing thumbs prevents direct pressure on ing investment must maintain its integrity at the
the pattern and facilitates removal16 (Fig 10-56). alloy's melting temperature and withstand the stress
At this point, the technician must apply the sprue that develops when the melted alloy enters the mold.
former using round rigid wax sections (available from The refractoy investment has an Bo% silicon di
Leach & Dillon), 3.0 or 3 - 5 mm in diameter depend oxide (SiO ) base in the form of quartz and cristoba·
ing on the volume of the element to be cast. The lite, which determines the refractory behavior of the
sprue-forming technique varies according to the in material and gives it a high degree of thermal expan FIG 10-56 FIG 10-57
tended method of casting. The authors prefer to use sion to compensate for the alloy's contraction during
a centrifugal casting method with blowtorch heating; the heating phase.•9 Because the alloy used for cast·
the axis of the casting will favor laminar flow and ing has medium-high gold content with a contraction
keep the alloy from making abrupt changes in direc that can be calculated at around 1.7°/o, the expansion
tion. In the authors' experience, applying the sprue of the refractory investment must ofset this contrac
former in perfect alignment with the axis of the wax tion to accurately reproduce the wax pattern.
pattern aids removal by greatly reducing the neces The bonding elements of magnesium oxide and am
sary force, which in turn transmits less stress to the monium phosphate help the materials combine dur
wax pattern and, therefore, reduces the possibility of ing mixing and set properly. The mixing liquid is a
a distortion that would be evident only after cast watery suspension of colloid silica (silica sol) and
ing'0 (Fig 10-57). The sprue former should be applied distilled water, generally in a ratio of 3:1. After i t is
according to the insertion axis of the pattern and mixed, the casting investment undergoes setting ex
positioned in the casting ring with the coping ori pansion to a degree primarily determined by the Fig 10-54 Removing the wax pattern from the die is very delicate work that could irreparably damage the restoration. The operator must
ented externally and away from the heat zone." The assume a correct and confident hand position with good elbow support to control even the slightest natural tremor.
concentration of the liquid (ie, the greater the con
Fig 10-55 Deformation of lhe wOK margin viewed under high magnification. with microcracks invisible lo lhe naked eye. Had it not been
authors recommend using a sprue at a distance of 2 centration of liquid, the greater the material's expan detected. lhe casting of the wax pattern would have reproduced these 1mperlect1ons.
to 3 mm from the coping to slow the ingress speed sion). Thermal expansion depends on the preheating Fig 10-56 Once lhe WOK pattern is removed from the die. the inner design of the preparation musl be checked.
of the alloy into the wax pattern so that it is not sub· temperature and the composition of silica i n the two Fig 10-57 Creation of sprue formers in WOK. For c � mplete crowns. lhe sprue former must be oriented along an axis that coincid_es with the
direction of removal. The application of vents. wh1ch are Situated away from the marg1nal closure. allows the release of the residual gases
jected to possible rebounds due to inadequate reg allotropic forms present. In this phase, water physi that are produced wilhin the investment during casting. These useful measures improve the quality of the cast restoration.
ulation of centrifugal thrust. cally bound to the interior of the macro· and micro· .
2 33
CHAPTER 1 0
.. Removal technique a n d preparation for CASTI N G

cast i n g
Investi n g proce dure
Successful removal o f t h e wax pattern from t h e die
is crucial to the preservation of accuracy achieved in The wax pattern is surrounded by refractory invest·
all previous prosthetic phases, especially when the ment for precision casting in gold alloy using the
procedure concerns several connected restorations. lost-wax technique. Investing must be performed
In removing the wax pattern, the operator must with extreme care and within 10 minutes of remov
assume a correct and confident hand position with ing the wax pattern from the die to minimize wax FIG 10-54 FIG 10-55
suficient elbow support to minimize the natural deformation from exposure to the surrounding con
tremor that could jeopardize precision'0·1 1 (Figs 10-54 ditions. Phosphate-bonded casting investments" have
and 10-55). The use of rubber dam improves the oper replaced those with a gypsum base because of the
ator's hold on the wax pattern, and exerting pressure higher melting temperatures of gold alloys.10 A cast
with opposing thumbs prevents direct pressure on ing investment must maintain its integrity at the
the pattern and facilitates removal16 (Fig 10-56). alloy's melting temperature and withstand the stress
At this point, the technician must apply the sprue that develops when the melted alloy enters the mold.
former using round rigid wax sections (available from The refractoy investment has an Bo% silicon di
Leach & Dillon), 3.0 or 3 - 5 mm in diameter depend oxide (SiO ) base in the form of quartz and cristoba·
ing on the volume of the element to be cast. The lite, which determines the refractory behavior of the
sprue-forming technique varies according to the in material and gives it a high degree of thermal expan FIG 10-56 FIG 10-57
tended method of casting. The authors prefer to use sion to compensate for the alloy's contraction during
a centrifugal casting method with blowtorch heating; the heating phase.•9 Because the alloy used for cast·
the axis of the casting will favor laminar flow and ing has medium-high gold content with a contraction
keep the alloy from making abrupt changes in direc that can be calculated at around 1.7°/o, the expansion
tion. In the authors' experience, applying the sprue of the refractory investment must ofset this contrac
former in perfect alignment with the axis of the wax tion to accurately reproduce the wax pattern.
pattern aids removal by greatly reducing the neces The bonding elements of magnesium oxide and am
sary force, which in turn transmits less stress to the monium phosphate help the materials combine dur
wax pattern and, therefore, reduces the possibility of ing mixing and set properly. The mixing liquid is a
a distortion that would be evident only after cast watery suspension of colloid silica (silica sol) and
ing'0 (Fig 10-57). The sprue former should be applied distilled water, generally in a ratio of 3:1. After i t is
according to the insertion axis of the pattern and mixed, the casting investment undergoes setting ex
positioned in the casting ring with the coping ori pansion to a degree primarily determined by the Fig 10-54 Removing the wax pattern from the die is very delicate work that could irreparably damage the restoration. The operator must
ented externally and away from the heat zone." The assume a correct and confident hand position with good elbow support to control even the slightest natural tremor.
concentration of the liquid (ie, the greater the con
Fig 10-55 Deformation of lhe wOK margin viewed under high magnification. with microcracks invisible lo lhe naked eye. Had it not been
authors recommend using a sprue at a distance of 2 centration of liquid, the greater the material's expan detected. lhe casting of the wax pattern would have reproduced these 1mperlect1ons.
to 3 mm from the coping to slow the ingress speed sion). Thermal expansion depends on the preheating Fig 10-56 Once lhe WOK pattern is removed from the die. the inner design of the preparation musl be checked.
of the alloy into the wax pattern so that it is not sub· temperature and the composition of silica i n the two Fig 10-57 Creation of sprue formers in WOK. For c � mplete crowns. lhe sprue former must be oriented along an axis that coincid_es with the
direction of removal. The application of vents. wh1ch are Situated away from the marg1nal closure. allows the release of the residual gases
jected to possible rebounds due to inadequate reg allotropic forms present. In this phase, water physi that are produced wilhin the investment during casting. These useful measures improve the quality of the cast restoration.
ulation of centrifugal thrust. cally bound to the interior of the macro· and micro· .
2 33
CHAPTER 1 0
ig 10-58 In accordance w1th the 1nstruct1ons supplied by the .. pact investment inhibits the elimination of gases, perature and reduce the oxidation of other non-noble
manufacturer. the mvestment I S placed 1n the plastiC cast1ng which can lead to serious im perfections in the cast components.
ring. Us1ng a brush. a drop of Investment is spread along the
internal surface of the wax core, this small amount of mater restoration. Obviously, the compositions of the various alloys
ial must stay between the wax pattern and the brush so that
the brush does not touch the delicate wax. produce different physical characteristics and hence
diferent responses to treatments and solicitations.
Alloys
Alloys used for metal-ceramic restorations must be
Casts must be inspected with a microscope to en· rigid and resilient and have a high flexion resistance
sure perfect adaptation of the metal coping to the to prevent elastic and plastic deformations during
die, faithful detail reproduction, and optimum mar ceramic firing. In changing from a solid to a liquid
ginal closure in metal. Casting systems and machines state, the alloy must experience the lowest possible
range from die-casting to blowtorch and induction, contraction from fusion, and to avoid the risk of dis
each of which produces excellent results when high tortion the fusion temperature must be high enough
quality materials are used and the technician has in for the metal to remain solid well beyond the ceram
.. porosities is discharged. Since the volume of water between the wax surface of the pattern and the instru depth knowledge of the characteristics and limits of ic firing temperature. During laboratory procedures,
vapor is about 1,700 times greater than that of water, ment. After the casting ring is filled with the refractory casting materials and techniques. In the authors' a good metal alloy must fuse and weld easily as
the investment must not be preheated too quickly or investment, it is placed in a hyperbaric curing flask at opinion, the quality of metal-ceramic restorations is well. The authors' experience over many years has
the increased volume due to steam formation may a pressure ranging from o.6 to o.S MPa. 22 Contrary to influenced more by the alloy selection than the cast shown that an alloy of 54% gold and 26.5% palla
break the casting ring. logic, the casting ring is made not of metal but plastic, ing technique, especially considering that its long dium (BegoStar, Bego) satisfies the numerous pre
Successful casting depends on several factors, in which creates uniform pressure within the investment term placement in the mouth can influence the pa requisites and provides excellent results.
cluding the performance of the phosphate investment, and on the entire surface of the wax pattern, thus tient's health. Thus, preference for dental castings
which can be influenced by liquid-powder ratio; tem avoiding significant distortions. falls to noble metals and their alloys, which guaran
Casting systems
perature; and above all, mixing time and speed. The The authors use one of the so-called new-generation tee excellent biocompatibility and good resistance
method by which the casting investment is mixed and casting investments (BellaStar, Bego). which have fast to thermal and mechanical deformations. The authors use a flame (blowtorch/blowpipe) cast
poured around the wax pattern will affect its chemical preheating cycles. When the manufacturer's instructions The three general classifications of noble metal ing system, which requires strict regulation of the
reaction and thus the quality of the casting. The tech are carefully followed, these reduce the risk of fracture alloys are precious metal alloys, containing So% to combustion gases (1.5 bars oxygen and o.s bars pro
nician can evaluate a cast restoration by its surface.10 or alteration in the investment and guarantee excellent 90% gold (high-carat gold); semiprecious metal pane) as well as adherence to other rules for a suc
To ensure that the surface of the cast coping will be results in the precision and quality of cast alloy. With alloys, containing so% gold (medium-carat gold); and cessful outcome. The regulated flame comprises four
smooth and nodule-free, after mixing the casting invest this type of casting investment, preheating in the kiln palladium-silver alloys, which contain no gold at all. characteristic zones: the colorless mixing zone, which
ment the technician must allow gas to escape from the can begin 25 minutes after the casting ring has been Most dental alloys also contain trace amounts of is in direct proximity to the nozzle; the greenish-blue
mixture by leaving it i n a vacuum from 10 to 15 sec filled; once the investment has hardened and is freed base metals, such as copper, zinc, tin, and indium.'9 combustion zone; the pale blue reduction zone,
onds. The subsequent pouring of the refractory invest from the plastic container, it can be placed directly into Precious metal alloys contain diferent components which is the area of greatest heat and thus suitable
ment into the casting ring should be managed careful the kiln for 30 minutes at a final temperature of about with characteristics and behavior fundamental to for melting the alloy; and the oxidizing zone at the
ly to prevent air bubbles from forming. Once the refrac Soo•c. Shortening the traditional preheating cycle pro their purpose and successful use. Gold is an ex extreme end of the flame, which should never be
tory investment reaches the height of the wax pattern, duces excellent results. As noted earlier, the authors tremely ductile and malleable metal with strong closer than 4 to 5 em to the metal.
a brush or a PKT-type metal instrument with a thin tip use a centrifugal casting system that requires careful resistance to corrosion. Silver has a high degree of During casting, the technician begins by melting
is used to layer the interior of the wax coping with a venting to release the gases that form from the chemi ductility and malleability. Platinum increases hard the alloy; the flame is maintained on the ingot and
small amount of investment, taking care to reproduce cal reactions and to help rapidly cool the pieces. This ness and corrosion resistance but has been almost removed an instant prior to injection into the cast
intricate details such as those in a partial crown prepa procedure is indispensable for the most recent genera entirely replaced by palladium due to its high cost. ing ring to prevent undesired oxidation. At the mo
ration (Fig 10-58). A layer of investment must remain tion of casting investments; fine-grained and more com- .. Zinc is a soft metal used to lower the melting tem- ment of liquefaction. the alloy forms a bubble that ..
4 335
CHAPTER 1 0
ig 10-58 In accordance w1th the 1nstruct1ons supplied by the .. pact investment inhibits the elimination of gases, perature and reduce the oxidation of other non-noble
manufacturer. the mvestment I S placed 1n the plastiC cast1ng which can lead to serious im perfections in the cast components.
ring. Us1ng a brush. a drop of Investment is spread along the
internal surface of the wax core, this small amount of mater restoration. Obviously, the compositions of the various alloys
ial must stay between the wax pattern and the brush so that
the brush does not touch the delicate wax. produce different physical characteristics and hence
diferent responses to treatments and solicitations.
Alloys
Alloys used for metal-ceramic restorations must be
Casts must be inspected with a microscope to en· rigid and resilient and have a high flexion resistance
sure perfect adaptation of the metal coping to the to prevent elastic and plastic deformations during
die, faithful detail reproduction, and optimum mar ceramic firing. In changing from a solid to a liquid
ginal closure in metal. Casting systems and machines state, the alloy must experience the lowest possible
range from die-casting to blowtorch and induction, contraction from fusion, and to avoid the risk of dis
each of which produces excellent results when high tortion the fusion temperature must be high enough
quality materials are used and the technician has in for the metal to remain solid well beyond the ceram
.. porosities is discharged. Since the volume of water between the wax surface of the pattern and the instru depth knowledge of the characteristics and limits of ic firing temperature. During laboratory procedures,
vapor is about 1,700 times greater than that of water, ment. After the casting ring is filled with the refractory casting materials and techniques. In the authors' a good metal alloy must fuse and weld easily as
the investment must not be preheated too quickly or investment, it is placed in a hyperbaric curing flask at opinion, the quality of metal-ceramic restorations is well. The authors' experience over many years has
the increased volume due to steam formation may a pressure ranging from o.6 to o.S MPa. 22 Contrary to influenced more by the alloy selection than the cast shown that an alloy of 54% gold and 26.5% palla
break the casting ring. logic, the casting ring is made not of metal but plastic, ing technique, especially considering that its long dium (BegoStar, Bego) satisfies the numerous pre
Successful casting depends on several factors, in which creates uniform pressure within the investment term placement in the mouth can influence the pa requisites and provides excellent results.
cluding the performance of the phosphate investment, and on the entire surface of the wax pattern, thus tient's health. Thus, preference for dental castings
which can be influenced by liquid-powder ratio; tem avoiding significant distortions. falls to noble metals and their alloys, which guaran
Casting systems
perature; and above all, mixing time and speed. The The authors use one of the so-called new-generation tee excellent biocompatibility and good resistance
method by which the casting investment is mixed and casting investments (BellaStar, Bego). which have fast to thermal and mechanical deformations. The authors use a flame (blowtorch/blowpipe) cast
poured around the wax pattern will affect its chemical preheating cycles. When the manufacturer's instructions The three general classifications of noble metal ing system, which requires strict regulation of the
reaction and thus the quality of the casting. The tech are carefully followed, these reduce the risk of fracture alloys are precious metal alloys, containing So% to combustion gases (1.5 bars oxygen and o.s bars pro
nician can evaluate a cast restoration by its surface.10 or alteration in the investment and guarantee excellent 90% gold (high-carat gold); semiprecious metal pane) as well as adherence to other rules for a suc
To ensure that the surface of the cast coping will be results in the precision and quality of cast alloy. With alloys, containing so% gold (medium-carat gold); and cessful outcome. The regulated flame comprises four
smooth and nodule-free, after mixing the casting invest this type of casting investment, preheating in the kiln palladium-silver alloys, which contain no gold at all. characteristic zones: the colorless mixing zone, which
ment the technician must allow gas to escape from the can begin 25 minutes after the casting ring has been Most dental alloys also contain trace amounts of is in direct proximity to the nozzle; the greenish-blue
mixture by leaving it i n a vacuum from 10 to 15 sec filled; once the investment has hardened and is freed base metals, such as copper, zinc, tin, and indium.'9 combustion zone; the pale blue reduction zone,
onds. The subsequent pouring of the refractory invest from the plastic container, it can be placed directly into Precious metal alloys contain diferent components which is the area of greatest heat and thus suitable
ment into the casting ring should be managed careful the kiln for 30 minutes at a final temperature of about with characteristics and behavior fundamental to for melting the alloy; and the oxidizing zone at the
ly to prevent air bubbles from forming. Once the refrac Soo•c. Shortening the traditional preheating cycle pro their purpose and successful use. Gold is an ex extreme end of the flame, which should never be
tory investment reaches the height of the wax pattern, duces excellent results. As noted earlier, the authors tremely ductile and malleable metal with strong closer than 4 to 5 em to the metal.
a brush or a PKT-type metal instrument with a thin tip use a centrifugal casting system that requires careful resistance to corrosion. Silver has a high degree of During casting, the technician begins by melting
is used to layer the interior of the wax coping with a venting to release the gases that form from the chemi ductility and malleability. Platinum increases hard the alloy; the flame is maintained on the ingot and
small amount of investment, taking care to reproduce cal reactions and to help rapidly cool the pieces. This ness and corrosion resistance but has been almost removed an instant prior to injection into the cast
intricate details such as those in a partial crown prepa procedure is indispensable for the most recent genera entirely replaced by palladium due to its high cost. ing ring to prevent undesired oxidation. At the mo
ration (Fig 10-58). A layer of investment must remain tion of casting investments; fine-grained and more com- .. Zinc is a soft metal used to lower the melting tem- ment of liquefaction. the alloy forms a bubble that ..
4 335
CHAPTER 1 0
laboratoy Procedures I
. moves in the crucible, slowly following the movement master die and then examine the adaptation under
of the flame; contact with the reduction zone of the 20X to JOX magnification, which makes visible any
flame gives the alloy a shiny appearance similar to closure defects on the margin (Figs 10-62 and 10-63).
that of a reflective surface (Fig 10·59). The operator In the case of partial crowns, the technician must
has only 5 to 7 seconds to centrifuge the alloy in the proceed to polishing the surface of the metal to final·
casting ring. The cast is allowed to cool to room tem ize the work. This conclusive and extremely delicate
perature, and at that point the technician proceeds to phase is always executed under magnification to pre
eliminate the investment, using the greatest care so vent damage. Small cylindrical rubber silicone points
as not to damage the metal structure, especially the (o182oB·9646.ooo.o2o, Kamel) are manufactured i n
thin metal borders. Removal of the investment inside diferent colors to distinguish between t h e different
the crown is performed under magnification using grits (ie, black for coarse grit, red for medium grit,
appropriate tungsten carbide burs; investment adher· and green for fine grit). When used in sequence, they
ing to the internal and external walls is removed after make the metal surface extremely shiny and eliminate
immersing the crown in a float chamber containing a any superficial microfurrows'6 (Figs 10-64 and 10-65).
15% hydroluoric acid solution and using ultrasound For metal-ceramic restorations, finishing the metal
for 15 minutes (Fig 10·6o). surface must be preceded by removal of the sprues
Sanding should absolutely be avoided; its heavy (Fig 10-66) and then rehomogenization of the cop·
impact on the cast could compromise the precision of ings. The latter is a thermal stabilization treatment
the work performed thus far, especially by rounding that is designed to reduce possible metal deforma
and irremediably damaging the metal edges. Before tions in subsequent ceramic firings. It is completed i n
proceeding to adaptation on the die, the cast should a ceramics kiln a t t h e manufacturer's recommended
be evaluated under a microscope for the presence of oxidation temperature for 10 minutes.
1 0- 6 2
imperfections, such as positive nodules or negative During casting, the melted alloy undergoes chemi·
depressions (Fig 10-61). Once this inspection has been cal separation of its components (crystals). Due to
completed, the technician can adapt the cast to the strong atmospheric interaction and the presence of .
Fig 10-59 Blowtorch casting system preferred by the authors. The flame must be accurately regulated and maintained on the
ingot until only an instant before the alloy is injected into the ring to prevent undesired oxidation. Fig 10-60 Resull of the par
tial crown casting. The shiny surface of the alloy reveals the quality of the work. which is the result of good waxing and cast
ing technique. Fig 10-61 Before putting the cast on the die. especially a plaster die. the technician must examine it under the
microscope for imperfections that could prevent correct adaptation. Fig 10-62 Marginal closure of the metal crown on the
plaster die. at high t32 X ) magnification. Fig 10-63 Successful result. The adaptation of the partial crown to the waits of the
intact tooth was accomplished using precise laboratory protocol. which was developed from years of experience with the
materials and techniques. Figs 10-64 and 10-65 Duality work must continue while polishing the metal margin or surface of a
partial crown. The precision contours so carefully achieved in the preceding phases must not be damaged. Fig 10-66 Cast alloy
tBegoStar) immediately prior to sprue removal. In the authors' opinion. an alloy of 54% gold and 26.5% palladium satisfies the
many requirements for an alloy for a cermet restoration.
CHAPTER 1 0
laboratoy Procedures I
. moves in the crucible, slowly following the movement master die and then examine the adaptation under
of the flame; contact with the reduction zone of the 20X to JOX magnification, which makes visible any
flame gives the alloy a shiny appearance similar to closure defects on the margin (Figs 10-62 and 10-63).
that of a reflective surface (Fig 10·59). The operator In the case of partial crowns, the technician must
has only 5 to 7 seconds to centrifuge the alloy in the proceed to polishing the surface of the metal to final·
casting ring. The cast is allowed to cool to room tem ize the work. This conclusive and extremely delicate
perature, and at that point the technician proceeds to phase is always executed under magnification to pre
eliminate the investment, using the greatest care so vent damage. Small cylindrical rubber silicone points
as not to damage the metal structure, especially the (o182oB·9646.ooo.o2o, Kamel) are manufactured i n
thin metal borders. Removal of the investment inside diferent colors to distinguish between t h e different
the crown is performed under magnification using grits (ie, black for coarse grit, red for medium grit,
appropriate tungsten carbide burs; investment adher· and green for fine grit). When used in sequence, they
ing to the internal and external walls is removed after make the metal surface extremely shiny and eliminate
immersing the crown in a float chamber containing a any superficial microfurrows'6 (Figs 10-64 and 10-65).
15% hydroluoric acid solution and using ultrasound For metal-ceramic restorations, finishing the metal
for 15 minutes (Fig 10·6o). surface must be preceded by removal of the sprues
Sanding should absolutely be avoided; its heavy (Fig 10-66) and then rehomogenization of the cop·
impact on the cast could compromise the precision of ings. The latter is a thermal stabilization treatment
the work performed thus far, especially by rounding that is designed to reduce possible metal deforma
and irremediably damaging the metal edges. Before tions in subsequent ceramic firings. It is completed i n
proceeding to adaptation on the die, the cast should a ceramics kiln a t t h e manufacturer's recommended
be evaluated under a microscope for the presence of oxidation temperature for 10 minutes.
1 0- 6 2
imperfections, such as positive nodules or negative During casting, the melted alloy undergoes chemi·
depressions (Fig 10-61). Once this inspection has been cal separation of its components (crystals). Due to
completed, the technician can adapt the cast to the strong atmospheric interaction and the presence of .
Fig 10-59 Blowtorch casting system preferred by the authors. The flame must be accurately regulated and maintained on the
ingot until only an instant before the alloy is injected into the ring to prevent undesired oxidation. Fig 10-60 Resull of the par
tial crown casting. The shiny surface of the alloy reveals the quality of the work. which is the result of good waxing and cast
ing technique. Fig 10-61 Before putting the cast on the die. especially a plaster die. the technician must examine it under the
microscope for imperfections that could prevent correct adaptation. Fig 10-62 Marginal closure of the metal crown on the
plaster die. at high t32 X ) magnification. Fig 10-63 Successful result. The adaptation of the partial crown to the waits of the
intact tooth was accomplished using precise laboratory protocol. which was developed from years of experience with the
materials and techniques. Figs 10-64 and 10-65 Duality work must continue while polishing the metal margin or surface of a
partial crown. The precision contours so carefully achieved in the preceding phases must not be damaged. Fig 10-66 Cast alloy
tBegoStar) immediately prior to sprue removal. In the authors' opinion. an alloy of 54% gold and 26.5% palladium satisfies the
many requirements for an alloy for a cermet restoration.
CHAPTER 1 0
Laboratory Procedures I
.. polluting agents such as powders, fluxes, invest applied to the gold a l loys most widely used in
ment, and ceramic materials, the metallographic char dentistry.'' When applied to the metal surface (Fig
acteristics of the resolidified alloy has been com· 10-67) and heated in a ceramics kiln at 950°C, the
pletely transformed from that of the original ingot: gel vitrifies and thereby insulates the metal from air;
The resolidified alloy is chemically strain-hardened in the absence of oxygen, oxides that have formed
with impurities, heavily oxidized elements, and inevit· during the casting cease formation. At the end of
able porosity. This crystalline imbalance creates a this procedure, the vitrified substance is removed Fl6 10-67 FIG 10-68
highly reactive electrochemical potential. Studies by with a 15% hydrofluoric acid solution that must be
Kuwata'J and Yamamoto'• have demonstrated that subsequently neutralized with a bicarbonate rinse.
finishing the metal surface before oxidation results The surface of the alloy appears very compact and
in imperfections in marginal closure. Through the shiny (Figs 10-68 and 10-69) with no free electrons
U N I F O R M I T Y 0 F T H E A l l 0 Y S U R F A C E
rehomogenization treatment, the homogeneous crys to create new undesired oxidations.
tal lattice structure of the alloy is restored, render Creating a high-quality framework depends on the
ing it much more stable under subsequent thermal design of the wax pattern; the casting and finishing
treatments and thus reducing the potential for pos· should be the logical outcome of the preparation
sible deformations. work accomplished during the modeling phase. For
New i n formation about the biocompatibility of this reason, when a ceramic margin is planned, it
dental alloys prompted the authors to establish a must be prepared in the design phase and in the
new prerequisite in their work protocol. In any pros wax pattern; only in this way can the technician
thetic restoration, the metal alloy must not only sat obtain a cast that ensures extremely precise adap·
isfy conditions of biocompatibility and expectations tation on the inner shoulder wall10 (Fig 10-70). Trying
of technical quality (eg, resistance to corrosion), but to eliminate an error by using a bur directly on the
it must also have a crystal lattice that is compact cast framework or improving adaptation through weld
and free of oxidizing elements. To this end, the den ing is considered unacceptable and can undermine FIG 10-70
FIG 10-69
tal technician can apply a compound that reorga the success of the entire restoration.
nizes the crystal lattice of gold-based precious metal During the waxup, the technician must determine
a lloys for subsequent ceramic firing. nsv Gel whether the structure will be connected and the
(Dental Technology) is a thermal treatment under a type of weld that is necessary, based on the frame·
vitreous layer that controls the effects of copper, work length. The framework design and connections
chrome, cobalt, nickel,'5·'6 and other trace elements require dimensions and a shape that can support
that are highly reactive and sensitive in ionic re the stress from occlusal force. •
lease. As part of a rigorous protocol, it can also be
Fig 10-67 After casting. TTSV gel is applied to treat precious gold-based alloys by reorganizing the crystal lattice for succes
sive phases of ceramic firing.
Figs 10-68 and 10-6g Comparison of the same casting before and after TTSV treatmenl. Note the luminous appearance of the
metal and the compactness of the alloy.
fig 10-70 Surface preparation of a complete crown. The buccal marginal closure will be layered in ceramic. as defined in the
design stage.
CHAPTER 1 0
Laboratory Procedures I
.. polluting agents such as powders, fluxes, invest applied to the gold a l loys most widely used in
ment, and ceramic materials, the metallographic char dentistry.'' When applied to the metal surface (Fig
acteristics of the resolidified alloy has been com· 10-67) and heated in a ceramics kiln at 950°C, the
pletely transformed from that of the original ingot: gel vitrifies and thereby insulates the metal from air;
The resolidified alloy is chemically strain-hardened in the absence of oxygen, oxides that have formed
with impurities, heavily oxidized elements, and inevit· during the casting cease formation. At the end of
able porosity. This crystalline imbalance creates a this procedure, the vitrified substance is removed Fl6 10-67 FIG 10-68
highly reactive electrochemical potential. Studies by with a 15% hydrofluoric acid solution that must be
Kuwata'J and Yamamoto'• have demonstrated that subsequently neutralized with a bicarbonate rinse.
finishing the metal surface before oxidation results The surface of the alloy appears very compact and
in imperfections in marginal closure. Through the shiny (Figs 10-68 and 10-69) with no free electrons
U N I F O R M I T Y 0 F T H E A l l 0 Y S U R F A C E
rehomogenization treatment, the homogeneous crys to create new undesired oxidations.
tal lattice structure of the alloy is restored, render Creating a high-quality framework depends on the
ing it much more stable under subsequent thermal design of the wax pattern; the casting and finishing
treatments and thus reducing the potential for pos· should be the logical outcome of the preparation
sible deformations. work accomplished during the modeling phase. For
New i n formation about the biocompatibility of this reason, when a ceramic margin is planned, it
dental alloys prompted the authors to establish a must be prepared in the design phase and in the
new prerequisite in their work protocol. In any pros wax pattern; only in this way can the technician
thetic restoration, the metal alloy must not only sat obtain a cast that ensures extremely precise adap·
isfy conditions of biocompatibility and expectations tation on the inner shoulder wall10 (Fig 10-70). Trying
of technical quality (eg, resistance to corrosion), but to eliminate an error by using a bur directly on the
it must also have a crystal lattice that is compact cast framework or improving adaptation through weld
and free of oxidizing elements. To this end, the den ing is considered unacceptable and can undermine FIG 10-70
FIG 10-69
tal technician can apply a compound that reorga the success of the entire restoration.
nizes the crystal lattice of gold-based precious metal During the waxup, the technician must determine
a lloys for subsequent ceramic firing. nsv Gel whether the structure will be connected and the
(Dental Technology) is a thermal treatment under a type of weld that is necessary, based on the frame·
vitreous layer that controls the effects of copper, work length. The framework design and connections
chrome, cobalt, nickel,'5·'6 and other trace elements require dimensions and a shape that can support
that are highly reactive and sensitive in ionic re the stress from occlusal force. •
lease. As part of a rigorous protocol, it can also be
Fig 10-67 After casting. TTSV gel is applied to treat precious gold-based alloys by reorganizing the crystal lattice for succes
sive phases of ceramic firing.
Figs 10-68 and 10-6g Comparison of the same casting before and after TTSV treatmenl. Note the luminous appearance of the
metal and the compactness of the alloy.
fig 10-70 Surface preparation of a complete crown. The buccal marginal closure will be layered in ceramic. as defined in the
design stage.
CHAPTER 1 0
R E F E R E N CES 7· McCabe IF. Applied Dental Materials. London: Blackwell, 15. Zehnder C. II nuovo modello di precisione con possibil 22. Raini . Fondere senza confondere: Scienza dei materi-
1985. ita di controllo ulteriore. Odontoinforma 1984;2:18-23. ali. Dent Labor 1999:5:497-507.
1. Wisser W. Scholz S, Lotzmann U. Comportamento di 8. Wolf I, Sondermann U, Lehmann KM. Fasi cristalline in 16. Semenza M. Principi biologici e tecnici nelle preparazioni 23. Kuwata M. Theel' and Practice for Ceramo - Metal Restor·
adesione e ritenzione dei gessi dentali. Team Work superfici di gesso. Team Work 1999:2:173-176. per corone parziali. Quaderni di progresso odontostom ations. Chicago: Quintessence, 1980.
2oo2;1:8o-B5. 9· Procaccini M, Baldoni E, Fagnani FR. Valutazione speri· atologico a cura degli. Amici di Brugg Odontoiatria 24. Yamamoto M. etal-Ceramics. Chicago: Quintessence,
2. Price RB, Gerrow JD. Sutow EJ. MacSween R. The dimen mentale sulla precisione e stabilita dimensionale delle 1998:15. 1985-
sional accuracy or 12 impression material and die stone resine epossidiche per modelli in protesi fissa. Quin· 17. Semenza M. Principi biologici e tecnici nelle preparazioni 25. Anastasia M, Cighetti G, Debiasi A, et al. Proposta di un
combinations. lnt I Prosthodont 1991;4:169-174- tessenza Odontotecnica 1992:4:341-356. per corone complete. Quaderni di progresso odontosto test per Ia valutazione della tossicita generate di teghe
3. McCormick JT. Antony SJ. Dial ML, Duncanson MG Jr. to. Massironi D. Battistelli A. Pascetta R. La Precisione Nella matologico a cura degli. Amici di Brugg Odontoiatria dentarie auree. Quintessence lnt 1994:3.
Shillingburg HT Jr. Wettability of elastomeric impression Restaurazione Protesica. Verona: Resch, 1993. 1996:14. 26. Wataha )C, Lewis JB. Lockwood PE. Rakich DR. Efect of
materials: Efect of selected surfactants. lnt J Prosth· 11. Martignoni M, Schonenberger AI. Precisione e contorno 18. Ohmacht P, Hasert G, Schneiderbanger . Cere dentali. dental metal ions on glutathione levels in THP·t human
odont 1989;2:413-420. nella ricostruzione protesica. Berlin: Quintessenz. 1987. Quintessenza Odontotecnica 2001;9:657-666. monocytes. J Oral Rehabil 2000;2]:5o8-516.
4· Hat H. Scienza dei materiali-gesso. Quintessenza Odonto· 12. Shillingburg HT, Hobo S. Whitsett LD. Fundamentals of 19. Philips RW. Science of Dental Materials. Philadelphia: 27. Paracchini L, Muto R. Studio della aderenza tra un met
tecnica 1990;7:665;67. Rxed Prosthodontics. Chicago: Quintessence, 1978:67. Saunders, 1991. alto a base nobile ed una vetro-ceramica. Quintessenza
5· Heft H, Kuske M. Tutto cio che si deve sapere sui gesso. 13. Pascetta R. Semplicita-precisione tricodent. Quintessenza 20. Wichnalek N. Modellazioni razionali ed ergonomiche. Odontotecnica 2001;5:387-397-
Dent Dialogue 2001;1:56. Odontotecnica 1988;t:19-28. Dent Dialogue 2001;1:84-87.
6. Heft H, Kuske M. Gesso: Tutto cio che si deve sapere. 14. Kalogiannidis K. Caratteristiche generali dei gessi per 21. Ohmacht P, Schmitt U, Zimmermann, Chopin R. Rivesti
Dent Dialogue 2002;2:156. Odontoiatria. II Dentista Moderno 1986:9:134-135· menti a legante fosfatico. Quintessenza Odontotecnica
2002;6:486-498.
4t
CHAPTER 1 0
R E F E R E N CES 7· McCabe IF. Applied Dental Materials. London: Blackwell, 15. Zehnder C. II nuovo modello di precisione con possibil 22. Raini . Fondere senza confondere: Scienza dei materi-
1985. ita di controllo ulteriore. Odontoinforma 1984;2:18-23. ali. Dent Labor 1999:5:497-507.
1. Wisser W. Scholz S, Lotzmann U. Comportamento di 8. Wolf I, Sondermann U, Lehmann KM. Fasi cristalline in 16. Semenza M. Principi biologici e tecnici nelle preparazioni 23. Kuwata M. Theel' and Practice for Ceramo - Metal Restor·
adesione e ritenzione dei gessi dentali. Team Work superfici di gesso. Team Work 1999:2:173-176. per corone parziali. Quaderni di progresso odontostom ations. Chicago: Quintessence, 1980.
2oo2;1:8o-B5. 9· Procaccini M, Baldoni E, Fagnani FR. Valutazione speri· atologico a cura degli. Amici di Brugg Odontoiatria 24. Yamamoto M. etal-Ceramics. Chicago: Quintessence,
2. Price RB, Gerrow JD. Sutow EJ. MacSween R. The dimen mentale sulla precisione e stabilita dimensionale delle 1998:15. 1985-
sional accuracy or 12 impression material and die stone resine epossidiche per modelli in protesi fissa. Quin· 17. Semenza M. Principi biologici e tecnici nelle preparazioni 25. Anastasia M, Cighetti G, Debiasi A, et al. Proposta di un
combinations. lnt I Prosthodont 1991;4:169-174- tessenza Odontotecnica 1992:4:341-356. per corone complete. Quaderni di progresso odontosto test per Ia valutazione della tossicita generate di teghe
3. McCormick JT. Antony SJ. Dial ML, Duncanson MG Jr. to. Massironi D. Battistelli A. Pascetta R. La Precisione Nella matologico a cura degli. Amici di Brugg Odontoiatria dentarie auree. Quintessence lnt 1994:3.
Shillingburg HT Jr. Wettability of elastomeric impression Restaurazione Protesica. Verona: Resch, 1993. 1996:14. 26. Wataha )C, Lewis JB. Lockwood PE. Rakich DR. Efect of
materials: Efect of selected surfactants. lnt J Prosth· 11. Martignoni M, Schonenberger AI. Precisione e contorno 18. Ohmacht P, Hasert G, Schneiderbanger . Cere dentali. dental metal ions on glutathione levels in THP·t human
odont 1989;2:413-420. nella ricostruzione protesica. Berlin: Quintessenz. 1987. Quintessenza Odontotecnica 2001;9:657-666. monocytes. J Oral Rehabil 2000;2]:5o8-516.
4· Hat H. Scienza dei materiali-gesso. Quintessenza Odonto· 12. Shillingburg HT, Hobo S. Whitsett LD. Fundamentals of 19. Philips RW. Science of Dental Materials. Philadelphia: 27. Paracchini L, Muto R. Studio della aderenza tra un met
tecnica 1990;7:665;67. Rxed Prosthodontics. Chicago: Quintessence, 1978:67. Saunders, 1991. alto a base nobile ed una vetro-ceramica. Quintessenza
5· Heft H, Kuske M. Tutto cio che si deve sapere sui gesso. 13. Pascetta R. Semplicita-precisione tricodent. Quintessenza 20. Wichnalek N. Modellazioni razionali ed ergonomiche. Odontotecnica 2001;5:387-397-
Dent Dialogue 2001;1:56. Odontotecnica 1988;t:19-28. Dent Dialogue 2001;1:84-87.
6. Heft H, Kuske M. Gesso: Tutto cio che si deve sapere. 14. Kalogiannidis K. Caratteristiche generali dei gessi per 21. Ohmacht P, Schmitt U, Zimmermann, Chopin R. Rivesti
Dent Dialogue 2002;2:156. Odontoiatria. II Dentista Moderno 1986:9:134-135· menti a legante fosfatico. Quintessenza Odontotecnica
2002;6:486-498.
4t
C H A P T E R 1 1
U S I N G C ERAM I C I N
P R O S T H E T I C RE S T O RAT I O N
FIG 1 1 - 1
M ETAL-CERA M I C CROWNS When using this method, the clincian must watch
for possible problems with the thin marginal metal, FIG 1 1 -2
which can undergo mechanical and thermal distor
Preparing the metal surface
tions, or undesired exposure of the rough opaque
The metal surface of the coping must be adequately layer that encourages plaque formation. In addition,
prepared to bond with the ceramic material, and spe the thickness of ceramic materials and the available
cial care should be taken at the margin to preserve space make it hard to avoid horizontal overcontour
the finish line design. For a better result and a ing, which can lead to microfractures from the clini
smooth surface, the metal surface should be finished cian's insertion force during cementation. Several
under a microscope using tungsten carbide burs and procedures can help the technician improve the
aluminum oxide points with a ceramic bonder (66t, micromargin. For example, the margin can first be
Komet). prepared in wax and then in metal; it can be made
The metal border in a metal-ceramic crown can be 1.5 mm high to increase stability and distortion resis
totally masked by layering ceramic and creating a tance during casting; it can be reduced when the
Fl6 1 1-3
micromargin. The dental technician must use a tech metal surface is being finished (Figs 11-1 and 11-2).
nique that maintains the precision of the preparation Using a microscope, the dental technician can shape
and avoids overcontouring the ceramic layer or dis the metal at the cervical margin, varying the angle of
torting the metal margin. The authors use Kuwata's' the restoration margin to widen the area of support
triangular formation theory of covering the metal (Fig 11-3). This counter-chamfer of the margin prepa
margin using a triangulated ceramic layer with an ration' (see chapter 4) preserves marginal precision
Figs 1 1 -1 and 11-2 Using the counter-chamfer technique. the coping margin is prepared in cermet. The metal border will be
angle that is wider than so degrees. during ceramic stratification and results in excellent layered with ceramic.
esthetics in this critical restoration zone. � Fig 11-3 Metal margin prepared with the counter-chamfer technique. shown at h1gh magnification.
42
C H A P T E R 1 1
U S I N G C ERAM I C I N
P R O S T H E T I C RE S T O RAT I O N
FIG 1 1 - 1
M ETAL-CERA M I C CROWNS When using this method, the clincian must watch
for possible problems with the thin marginal metal, FIG 1 1 -2
which can undergo mechanical and thermal distor
Preparing the metal surface
tions, or undesired exposure of the rough opaque
The metal surface of the coping must be adequately layer that encourages plaque formation. In addition,
prepared to bond with the ceramic material, and spe the thickness of ceramic materials and the available
cial care should be taken at the margin to preserve space make it hard to avoid horizontal overcontour
the finish line design. For a better result and a ing, which can lead to microfractures from the clini
smooth surface, the metal surface should be finished cian's insertion force during cementation. Several
under a microscope using tungsten carbide burs and procedures can help the technician improve the
aluminum oxide points with a ceramic bonder (66t, micromargin. For example, the margin can first be
Komet). prepared in wax and then in metal; it can be made
The metal border in a metal-ceramic crown can be 1.5 mm high to increase stability and distortion resis
totally masked by layering ceramic and creating a tance during casting; it can be reduced when the
Fl6 1 1-3
micromargin. The dental technician must use a tech metal surface is being finished (Figs 11-1 and 11-2).
nique that maintains the precision of the preparation Using a microscope, the dental technician can shape
and avoids overcontouring the ceramic layer or dis the metal at the cervical margin, varying the angle of
torting the metal margin. The authors use Kuwata's' the restoration margin to widen the area of support
triangular formation theory of covering the metal (Fig 11-3). This counter-chamfer of the margin prepa
margin using a triangulated ceramic layer with an ration' (see chapter 4) preserves marginal precision
Figs 1 1 -1 and 11-2 Using the counter-chamfer technique. the coping margin is prepared in cermet. The metal border will be
angle that is wider than so degrees. during ceramic stratification and results in excellent layered with ceramic.
esthetics in this critical restoration zone. � Fig 11-3 Metal margin prepared with the counter-chamfer technique. shown at h1gh magnification.
42
CHAPTER 1 1
Using Ceramic i n Prosthetic Restoration
.. CERAMIC MATERIAL are compatibile with the alloy; the firing temperature
of the ceramic must be below the liquefying temper
Application of an esthetic layer-the final esthetic ature of the metal. Research indicates that if the
stage for a metal-ceramic crown- must be performed metal alloy liquifies at a temperature that is at least
Fig 1 1 -4 The surface of the metal coping is prepared
with extreme care so as to preserve the precision of 150°C higher than that of ceramic firing, then distor with a carboru ndum bur IKometl to encourage
bonding with the opaque layer. with the exclusiOn
the metal coping. Since the esthetics of the restora tions in the metal structure, particularly at the thin
of the margin. which is never roughened or pol
tion is the most immediate evaluation criterion, espe margin, will be reduced or eliminated.'-6-7 It is i m por ished during this phase.
cially for the patient, all efforts must be made to imi tant to check the stability of the metal framework
tate natural tooth morphology. New materials provide prior to application of the ceramic; any metal defor
esthetics, biocompatibility, and resistance that make mation produced by occlusal force can damage the . layer. Obtaining superior quality esthetics in this area margin without altering precision (Figs 11-9 and 11-10).
it possible to obtain high-quality results with metal nonelastic ceramic layer and lead to microfracturing is especially challenging. Furthermore, the restoration The technician must then apply a highly luorescent
ceramic restorations. of the ceramic. For the same reason, the walls of the margin is in direct contact with gingival tissue, where porcelain at the margin (Silhouette Secret, Leach &
Dental ceramic is chemically classified as a vitre metal coping must have a homogeneous thickness of unsightly and inadequate margins can have serious Dillon) to increase the effect of luminosity in the cer
ous complex silicate composed of feldspars, quartz, no less than 0.5 mm so that they can react uniform consequences for future periodontal health. vical area. When these steps have been completed,
and kaolin, whose characteristics largely depend on ly to both functional and thermal stress. Even when there is a perfect 360-degree closure on dentin-type material can be used to create the opti
the components that have been added to it. The first Maintaining the space that was designed for the the margin of the metal substrate, the ceramic shoul mal tooth anatomy (Fig 11-11).
feldspar-based ceramics were very fragile and demon metal and ceramic within the finished restoration is der must be correctly fabricated to avoid overercon Layering some porcelain effects in the incisal area
strated poor resistance to abrasion and cutting. important to esthetics as well. In fabricating the cop touring of the edges and to minimize the lack of (Silhouette Whisper, Leach & Dillon) enables techni
These materials frequently fractured during use and transparency inherent in using a metal substrate. cians to attain a shape with optimal imitation of the
ing, the technician must maintain adequate space for
Treating the metal surface with TISV (thermal treat surface textures, which enhances the natural appear
could not be adapted for good marginal closure the ceramic material, normally ranging from 1.0 to 1.5
ment under a vitreous layer) Gel (Dental Technology) ance of the restoration (Figs 11-12 and 11-1)}. The
because of the diiculty of controlling volumetric con mm in the central area and 1.5 to 2.0 mm in the
limits oxide formation and reduces the formation of application of stain to i mprove appearance and the
traction during the sintering phase.J-S Moreover, the incisal area 6 The degree of thickness plays a signifi
ugly gray halos on the gingiva that are generated by subsequent marginal finishing must not compromise
opacity of the material was overaccentuated. The cant role in the natural appearance that can be
metal's electrochemical reaction 8·9 After the metal at the marginal precision. From a biologic standpoint, a
composition of dental ceramic has since undergone achieved with correct ceramic layering. This aspect is
the margin has been prepared, the surface of the cop highly smooth marginal surface is necessary for per
numerous innovations. For example, alumina com particularly important for metal-ceramic restorations
ing is finished with a carborundum bur (7)).104.2)0, fect integration of the prosthesis (Figs 11-14 to 11-16).
pounds and other additives, such as leucite, raised because the metal substrate creates a barrier that
Komet}, which provides a uniform roughness (so to Even in the palatal zone, polishing the metal mar
the thermal expansion coefficient and melting point, prevents tight from passing through the porcelain
6o mm) to improve the bond between metal and gin is a delicate procedure that must be performed
i mproved the adhesion of the ceramic material to the layer. Thus, the technician must take advantage of
ceramic (Fig 11-4). carefully, preferably with a microscope. To achieve an
metal, and provided greater fracture resistance. the translucence and fluorescence of the ceramic
extremely smooth surface while maintaining the
Esthetic improvements were achieved by increasing material to mimic the light effects of natural tooth
crown's vertical and horizontal contours, the authors
the material's opalescence and translucence to and all-ceramic restorations. CERAM I C LAYERING
use abrasive silicone points (no. 0182o8-9646.oo.o2o,
enhance the vitality of the restoration. Restorations
Stratification begins with the application of opaque Komet) of three diferent grits; the final green, fine
with a metal substrate integrate better with the nat
porcelain to mask the metal at the cervical margin. grit point leaves the surface perfectly smooth and de
ural dentition when ceramic materials compensate for TR EATI N G THE M ETAL AT THE
After firing the first opaque layer, the technician can void of superficial micro furrows (Figs 11-17 and 11-18).
the lack of light penetration. CERVICAL MARG I N
evaluate the structural stability at the margin (Figs Such careful attention to the margin of a metal-ceramic
Because of the complexity of applying ceramic to
11-5 and 11-6). For the second layer, a thin layer of crown guarantees its integration with the surrounding
a metal coping, the dental technician must check the Before ceramic application, the correct treatment of
opaque paste (Silhouette Easee-Pake, Leach & Dillon) tissue (Fig 11-19). .
accuracy of each procedure, step by step. First, the the cervical margin must be properly prepared because
choice of layering ceramic is narrowed to those that of the thinness of both the metal structure and ceramic . (Figs 11-7 and 11-8) is applied to mask the cevical
CHAPTER 1 1
.. CERAMIC MATERIAL are compatibile with the alloy; the firing temperature
of the ceramic must be below the liquefying temper
Application of an esthetic layer-the final esthetic ature of the metal. Research indicates that if the
stage for a metal-ceramic crown- must be performed metal alloy liquifies at a temperature that is at least
Fig 1 1 -4 The surface of the metal coping is prepared
with extreme care so as to preserve the precision of 150°C higher than that of ceramic firing, then distor with a carboru ndum bur IKometl to encourage
bonding with the opaque layer. with the exclusiOn
the metal coping. Since the esthetics of the restora tions in the metal structure, particularly at the thin
of the margin. which is never roughened or pol
tion is the most immediate evaluation criterion, espe margin, will be reduced or eliminated.'-6-7 It is i m por ished during this phase.
cially for the patient, all efforts must be made to imi tant to check the stability of the metal framework
tate natural tooth morphology. New materials provide prior to application of the ceramic; any metal defor
esthetics, biocompatibility, and resistance that make mation produced by occlusal force can damage the . layer. Obtaining superior quality esthetics in this area margin without altering precision (Figs 11-9 and 11-10).
it possible to obtain high-quality results with metal nonelastic ceramic layer and lead to microfracturing is especially challenging. Furthermore, the restoration The technician must then apply a highly luorescent
ceramic restorations. of the ceramic. For the same reason, the walls of the margin is in direct contact with gingival tissue, where porcelain at the margin (Silhouette Secret, Leach &
Dental ceramic is chemically classified as a vitre metal coping must have a homogeneous thickness of unsightly and inadequate margins can have serious Dillon) to increase the effect of luminosity in the cer
ous complex silicate composed of feldspars, quartz, no less than 0.5 mm so that they can react uniform consequences for future periodontal health. vical area. When these steps have been completed,
and kaolin, whose characteristics largely depend on ly to both functional and thermal stress. Even when there is a perfect 360-degree closure on dentin-type material can be used to create the opti
the components that have been added to it. The first Maintaining the space that was designed for the the margin of the metal substrate, the ceramic shoul mal tooth anatomy (Fig 11-11).
feldspar-based ceramics were very fragile and demon metal and ceramic within the finished restoration is der must be correctly fabricated to avoid overercon Layering some porcelain effects in the incisal area
strated poor resistance to abrasion and cutting. important to esthetics as well. In fabricating the cop touring of the edges and to minimize the lack of (Silhouette Whisper, Leach & Dillon) enables techni
These materials frequently fractured during use and transparency inherent in using a metal substrate. cians to attain a shape with optimal imitation of the
ing, the technician must maintain adequate space for
Treating the metal surface with TISV (thermal treat surface textures, which enhances the natural appear
could not be adapted for good marginal closure the ceramic material, normally ranging from 1.0 to 1.5
ment under a vitreous layer) Gel (Dental Technology) ance of the restoration (Figs 11-12 and 11-1)}. The
because of the diiculty of controlling volumetric con mm in the central area and 1.5 to 2.0 mm in the
limits oxide formation and reduces the formation of application of stain to i mprove appearance and the
traction during the sintering phase.J-S Moreover, the incisal area 6 The degree of thickness plays a signifi
ugly gray halos on the gingiva that are generated by subsequent marginal finishing must not compromise
opacity of the material was overaccentuated. The cant role in the natural appearance that can be
metal's electrochemical reaction 8·9 After the metal at the marginal precision. From a biologic standpoint, a
composition of dental ceramic has since undergone achieved with correct ceramic layering. This aspect is
the margin has been prepared, the surface of the cop highly smooth marginal surface is necessary for per
numerous innovations. For example, alumina com particularly important for metal-ceramic restorations
ing is finished with a carborundum bur (7)).104.2)0, fect integration of the prosthesis (Figs 11-14 to 11-16).
pounds and other additives, such as leucite, raised because the metal substrate creates a barrier that
Komet}, which provides a uniform roughness (so to Even in the palatal zone, polishing the metal mar
the thermal expansion coefficient and melting point, prevents tight from passing through the porcelain
6o mm) to improve the bond between metal and gin is a delicate procedure that must be performed
i mproved the adhesion of the ceramic material to the layer. Thus, the technician must take advantage of
ceramic (Fig 11-4). carefully, preferably with a microscope. To achieve an
metal, and provided greater fracture resistance. the translucence and fluorescence of the ceramic
extremely smooth surface while maintaining the
Esthetic improvements were achieved by increasing material to mimic the light effects of natural tooth
crown's vertical and horizontal contours, the authors
the material's opalescence and translucence to and all-ceramic restorations. CERAM I C LAYERING
use abrasive silicone points (no. 0182o8-9646.oo.o2o,
enhance the vitality of the restoration. Restorations
Stratification begins with the application of opaque Komet) of three diferent grits; the final green, fine
with a metal substrate integrate better with the nat
porcelain to mask the metal at the cervical margin. grit point leaves the surface perfectly smooth and de
ural dentition when ceramic materials compensate for TR EATI N G THE M ETAL AT THE
After firing the first opaque layer, the technician can void of superficial micro furrows (Figs 11-17 and 11-18).
the lack of light penetration. CERVICAL MARG I N
evaluate the structural stability at the margin (Figs Such careful attention to the margin of a metal-ceramic
Because of the complexity of applying ceramic to
11-5 and 11-6). For the second layer, a thin layer of crown guarantees its integration with the surrounding
a metal coping, the dental technician must check the Before ceramic application, the correct treatment of
opaque paste (Silhouette Easee-Pake, Leach & Dillon) tissue (Fig 11-19). .
accuracy of each procedure, step by step. First, the the cervical margin must be properly prepared because
choice of layering ceramic is narrowed to those that of the thinness of both the metal structure and ceramic . (Figs 11-7 and 11-8) is applied to mask the cevical
CHAPHR 1 1
Using Ceramic in Prosthetic Restoration
figs 1 1 -5 and 1 1 -6 Metal margin before and after application of the first layer of opaque liquid. Note the stability of the metal at 32 x magni Figs 11-11 and 11-12 Stratification of the ceramic with dentin-type material and incisal effects (Silhouette Whisper). Fig 11-13 Finalization of
fication. figs 1 1 -7 and 11-8 Application of opaque ceramic (Silhouette Easee-Pake) at the margin under high magnification 120 X). figs 1 1 -g and the ceramic in its entire form. The technician had to imitate the root of the tooth due to gingival recession. figs 11-14 and 11-15 Cermet
11-10 Once the opaque layer has been fired the crown is positioned on the die. The margin precision is evident at 20 x and 3 2 X magnification. restoration with micromargin closure and precise contours and surfaces. Fig 1 1 -16 Interior of a ceramic- coated crown. There is no evidence
of excess ceramic at the inner margin of the metal.
47
CHAPHR 1 1
figs 1 1 -5 and 1 1 -6 Metal margin before and after application of the first layer of opaque liquid. Note the stability of the metal at 32 x magni Figs 11-11 and 11-12 Stratification of the ceramic with dentin-type material and incisal effects (Silhouette Whisper). Fig 11-13 Finalization of
fication. figs 1 1 -7 and 11-8 Application of opaque ceramic (Silhouette Easee-Pake) at the margin under high magnification 120 X). figs 1 1 -g and the ceramic in its entire form. The technician had to imitate the root of the tooth due to gingival recession. figs 11-14 and 11-15 Cermet
11-10 Once the opaque layer has been fired the crown is positioned on the die. The margin precision is evident at 20 x and 3 2 X magnification. restoration with micromargin closure and precise contours and surfaces. Fig 1 1 -16 Interior of a ceramic- coated crown. There is no evidence
of excess ceramic at the inner margin of the metal.
47
CHAPTER 1 1
. Cera m ic m icromarg i n isolating the die, this thermoplastic material is applied

with an electric spatula in areas showing defects; the
While a metal margin provides greater precision and crown is then removed from the die for another firing
sturdiness than a ceramic margin, the esthetics of the (Fig 11·22).
restoration, especially in anterior restorations, must be If the technician wishes to enhance the natural ap·
considered as well. Thus, during the design and wax pearance of the restoration for better integration with
pattern stages, the technician must explore the option existing dentition, chromatic characterizations can be
of reducing the metal margin and modifying its design applied before the last firing, in a procedure called
(particularly on the buccal side) to create sufficient correction iring (Figs 11-23 to 11·25). This corrective fir·
room for ceramic layering, which also improves the ing provides excellent marginal precision (Figs 11-26 to
appearance of the gingiva2• 10 (Fig 11-20). A ceramic 11·28). The final step consists of manually polishing the
margin requires a horizontal or chamfer preparation of crown for better control over the degree of shine and
the shoulder, with rounding of the inner angle. finish (Figs 11-29 to 11-31).
After the opaque ceramic has been applied to the
prepared metal substrate, the shoulder of the die is Alternative materials
coated with isolating material to facilitate subsequent The development of alternative materials to traditional
removal of the crown during the various layering phas· metal-ceramic components represents an improvement
es. The shoulder porcelain is strong and nuorescent in both esthetics and biologic compatibility. For exam
(Silhouette Shoulder, Leach & Dillon) to enhance light ple, Captek (Leach & Dillon) is an oxide-free compound
diffusion at the margin. The ceramic material should alloy with a high gold content"·" that requires a mini
not be too nuid so that it can be compacted toward mum wall thickness of only 0.25 mm. This ofers clini
the cervical margin. Once the application is dry, the cal advantages when vertical finish lines are used, such
crown is gently removed from the die and fired. Only as preparations with a peripheral bevel or a feather
ater the crown is thoroughly cooled and replaced on edge (Figs 11·32 and 11·33). Moreover, Captek can be
the die will any imperfections in the porcelain caused combined with the traditional alloys to fabricate fixed
by contraction be evident (Fig 11-21). These defects partial dentures. A perfectly compatible joint weld be·
and imperfections can be corrected with later firings. tween the two materials makes the entire structure
Once the die has been cleaned and re-isolated, more strong and provides superior tensile strength (Figs 11·
shoulder porcelain is applied i n the same manner, 34 to 11·36). The characteristics of this material
again making sure that the ceramic is well compacted enhance the properties of ceramic, '3 ensuring excellent
1 1 -2 1
to minimize the efects of shrinkage in the subsequent margin precision and chromatic warmth, even in the
firing. The technician then completes the anatomic presence of very conservative preparations. Captek gives
shape of the crown. In the final firing, the authors the ceramic greater esthetic vitality due to better refrac·
always use a thermoplastic product composed of tion of glancing light, which results in a more natural·
ceramic and wax to improve marginal closure. After re· looking restoration (Figs 11-37 and 11-38). ..
Fig 11-17 Metal margin polished with special silicone points. Fig 11-18 Precise contour of the metal margin. Fig 1 1 -1 g Cermet crowns in place.
Obtaining good esthetic integration with a cermet restoration is more complicated for the dental technician than using all-ceramic materials
or a ceramic layer on an aluminum-like substrate. Fi g 11-20 Finishing the surface of the metal coping and preparing for the creation of a
ceramic shoulder. Ftg 11-21 After the first firing of the ceramic shoulder. there is an undesired ceramic contraction at the margin. Fig 11-22
Thermoplastic material is applied with an electric brush to offset ceramic shrinkage at the margin.
41
CHAPTER 1 1
. Cera m ic m icromarg i n isolating the die, this thermoplastic material is applied

with an electric spatula in areas showing defects; the
While a metal margin provides greater precision and crown is then removed from the die for another firing
sturdiness than a ceramic margin, the esthetics of the (Fig 11·22).
restoration, especially in anterior restorations, must be If the technician wishes to enhance the natural ap·
considered as well. Thus, during the design and wax pearance of the restoration for better integration with
pattern stages, the technician must explore the option existing dentition, chromatic characterizations can be
of reducing the metal margin and modifying its design applied before the last firing, in a procedure called
(particularly on the buccal side) to create sufficient correction iring (Figs 11-23 to 11·25). This corrective fir·
room for ceramic layering, which also improves the ing provides excellent marginal precision (Figs 11-26 to
appearance of the gingiva2• 10 (Fig 11-20). A ceramic 11·28). The final step consists of manually polishing the
margin requires a horizontal or chamfer preparation of crown for better control over the degree of shine and
the shoulder, with rounding of the inner angle. finish (Figs 11-29 to 11-31).
After the opaque ceramic has been applied to the
prepared metal substrate, the shoulder of the die is Alternative materials
coated with isolating material to facilitate subsequent The development of alternative materials to traditional
removal of the crown during the various layering phas· metal-ceramic components represents an improvement
es. The shoulder porcelain is strong and nuorescent in both esthetics and biologic compatibility. For exam
(Silhouette Shoulder, Leach & Dillon) to enhance light ple, Captek (Leach & Dillon) is an oxide-free compound
diffusion at the margin. The ceramic material should alloy with a high gold content"·" that requires a mini
not be too nuid so that it can be compacted toward mum wall thickness of only 0.25 mm. This ofers clini
the cervical margin. Once the application is dry, the cal advantages when vertical finish lines are used, such
crown is gently removed from the die and fired. Only as preparations with a peripheral bevel or a feather
ater the crown is thoroughly cooled and replaced on edge (Figs 11·32 and 11·33). Moreover, Captek can be
the die will any imperfections in the porcelain caused combined with the traditional alloys to fabricate fixed
by contraction be evident (Fig 11-21). These defects partial dentures. A perfectly compatible joint weld be·
and imperfections can be corrected with later firings. tween the two materials makes the entire structure
Once the die has been cleaned and re-isolated, more strong and provides superior tensile strength (Figs 11·
shoulder porcelain is applied i n the same manner, 34 to 11·36). The characteristics of this material
again making sure that the ceramic is well compacted enhance the properties of ceramic, '3 ensuring excellent
1 1 -2 1
to minimize the efects of shrinkage in the subsequent margin precision and chromatic warmth, even in the
firing. The technician then completes the anatomic presence of very conservative preparations. Captek gives
shape of the crown. In the final firing, the authors the ceramic greater esthetic vitality due to better refrac·
always use a thermoplastic product composed of tion of glancing light, which results in a more natural·
ceramic and wax to improve marginal closure. After re· looking restoration (Figs 11-37 and 11-38). ..
Fig 11-17 Metal margin polished with special silicone points. Fig 11-18 Precise contour of the metal margin. Fig 1 1 -1 g Cermet crowns in place.
Obtaining good esthetic integration with a cermet restoration is more complicated for the dental technician than using all-ceramic materials
or a ceramic layer on an aluminum-like substrate. Fi g 11-20 Finishing the surface of the metal coping and preparing for the creation of a
ceramic shoulder. Ftg 11-21 After the first firing of the ceramic shoulder. there is an undesired ceramic contraction at the margin. Fig 11-22
Thermoplastic material is applied with an electric brush to offset ceramic shrinkage at the margin.
41
'Ar r
Figs 11-23 and 11-24 For correction firing. the technician can add small amounts of material to improve the final appearance of the restoration.
Fig 11-25 Special care in creating and polishing the occlusal surface at high magnification can enhance the esthetics and function.
Figs 1 1 -26 to 1 1 -28 Marginal closure on the die at 20 x. 1 2 x. and 50 X magnification.
Fig 11-2g Marginal profile of the crown after finishing and polishing on the master cast.
Fig 1 1 -30 Interior edge of the crown. Note the compactness of the shoulder ceramic. the border of the metal margin. and the perfect integra
1 1 ·2 8
tion of the two materials.
30 351
'Ar r
Figs 11-23 and 11-24 For correction firing. the technician can add small amounts of material to improve the final appearance of the restoration.
Fig 11-25 Special care in creating and polishing the occlusal surface at high magnification can enhance the esthetics and function.
Figs 1 1 -26 to 1 1 -28 Marginal closure on the die at 20 x. 1 2 x. and 50 X magnification.
Fig 11-2g Marginal profile of the crown after finishing and polishing on the master cast.
Fig 1 1 -30 Interior edge of the crown. Note the compactness of the shoulder ceramic. the border of the metal margin. and the perfect integra
1 1 ·2 8
tion of the two materials.
30 351
Fig 11-31 Highly esthetic restoration. Figs 1 1 -32 and 11-33 This anterior restoration requires good esthetics. Fig 11 -34 Oxide-free materials can istic dark color of metal. Figs 11-35 and 11 -36 Construction of a fixed partial denture. The connection with the Captek crowns was created with
be used as alternatives to cermet. Captek is an innovative material that guarantees better esthetics because it does not have the character- a high-gold-content weld. Fig 11-37 Ceramic layer of the fixed partial denture on the cast. Fig 1 1 -38 Definitive result after cementation.
352 3
Fig 11-31 Highly esthetic restoration. Figs 1 1 -32 and 11-33 This anterior restoration requires good esthetics. Fig 11 -34 Oxide-free materials can istic dark color of metal. Figs 11-35 and 11 -36 Construction of a fixed partial denture. The connection with the Captek crowns was created with
be used as alternatives to cermet. Captek is an innovative material that guarantees better esthetics because it does not have the character- a high-gold-content weld. Fig 11-37 Ceramic layer of the fixed partial denture on the cast. Fig 1 1 -38 Definitive result after cementation.
352 3
CHAPTER 1 1
.. H EAT- P RESSED ALL-CERAM I C for fixed partial dentures to inlays or onlays and
R ESTORATI O N S laminate veneers. Today, the various ceramic sys·

tens use different components and require their
Any discussion o f the systems used t o fabricate own unique laboratory protocols, which in some
individual crowns or frameworks for fixed partial cases involve the use of computerized machinery
dentures must address the latest technological ad· and equipment like the computer-assisted design
vances, such as all-ceramic materials. An increasing (CAD) and computer-assisted manufacture (CAM)
demand for esthetics and greater biocompatibility of technology that is discussed later in this chapter.
dental alloys has led to the development of viable Dental technicians must analyze a clinical case dur·
all-ceramic materials. ing the preliminary treatment phase to assess the
Although the first all-ceramic restoration dates prosthetic requirements and determine the system
back to the 17th century, 300 years passed before best suited to the case.
the possibility of all-ceramic restorations was
explored in depth.' At the turn of the 2oth century,
Heat-pressed all-cera m i c systems
Land created a crown entirely from feldspathic
ceramic (a material that is still used. though with The heat-pressing technique was first tested as long
improved composition), and a few years later, ago as 1938, but the technique became widely used
Mclean and Hughes made the first crowns in ceram· only in the last decade) Two diferent techniques
ic with an aluminum oxide additive. 2 have been developed for the use of heat-pressed all·
During the last 20 years, research and i nnovation ceramic systems: ) The entire restoration can be
in dentisty have produced materials with abrasion fabricated with heat-pressed material, and surface
and chemical resistance similar to natural enamel color can be subsequently added using special stain,
that guarantee excellent esthetics. This is particular· or (2) a ceramic core can be fabricated, to which sur·
ly true of the new ceramic materials, which provide face efects and details are stratified with the addi·
outstanding opalescence, translucence, and trans tion of low-fusing ceramic materialsJ-7 (Cerpress
parency. Indications for the current generation of all· Sensation SL, Leach & Dillon; IPS Empress, lvoclar
ceramic materials have expanded to include fixed Vivadent; Presskeramik Evopress. Wegold). Both
patial dentures and posterior restorations, with techniques require the creation of a master cast with
increasing esthetic and functional satisfaction. The removable dies and the preparation of a wax pattern
most popular material for all-ceramic restoration is a (Cerpress SL Carving Wax, Leach & Dillon), according
ceramic to which vitreous substances like leucite or to the technical principles previously discussed (see
hydroxyapatite have been added; the material also chapter 10) (Figs 11-39 to 11-41). Using the lost wax
contains oxides of aluminum, magnesium, or zirco· technique, the technician attaches sprue formers to
nium to augment the light refraction and hardness the wax pattern (Fig 11·42), invests the wax pattern,
Fig 1 1 -Jg Clinical situation requiring the esthetic restoration of two lateral incisors using pressable die-cast ceramic ICerpress SL).
of the material. Such ceramics are used in all types and finally, using the technique explained later in
Figs 11 -40 and 1 1 -41 Master cast and preparation of the d i es .
of restoration, from individual crowns to frameworks this chapter, heat-presses the ceramic. ,.
Fig 1 1-42 Copings are waxed and sprue formers attached in a manner similar to that used for metal casting.
CHAPTER 1 1
.. H EAT- P RESSED ALL-CERAM I C for fixed partial dentures to inlays or onlays and
R ESTORATI O N S laminate veneers. Today, the various ceramic sys·

tens use different components and require their
Any discussion o f the systems used t o fabricate own unique laboratory protocols, which in some
individual crowns or frameworks for fixed partial cases involve the use of computerized machinery
dentures must address the latest technological ad· and equipment like the computer-assisted design
vances, such as all-ceramic materials. An increasing (CAD) and computer-assisted manufacture (CAM)
demand for esthetics and greater biocompatibility of technology that is discussed later in this chapter.
dental alloys has led to the development of viable Dental technicians must analyze a clinical case dur·
all-ceramic materials. ing the preliminary treatment phase to assess the
Although the first all-ceramic restoration dates prosthetic requirements and determine the system
back to the 17th century, 300 years passed before best suited to the case.
the possibility of all-ceramic restorations was
explored in depth.' At the turn of the 2oth century,
Heat-pressed all-cera m i c systems
Land created a crown entirely from feldspathic
ceramic (a material that is still used. though with The heat-pressing technique was first tested as long
improved composition), and a few years later, ago as 1938, but the technique became widely used
Mclean and Hughes made the first crowns in ceram· only in the last decade) Two diferent techniques
ic with an aluminum oxide additive. 2 have been developed for the use of heat-pressed all·
During the last 20 years, research and i nnovation ceramic systems: ) The entire restoration can be
in dentisty have produced materials with abrasion fabricated with heat-pressed material, and surface
and chemical resistance similar to natural enamel color can be subsequently added using special stain,
that guarantee excellent esthetics. This is particular· or (2) a ceramic core can be fabricated, to which sur·
ly true of the new ceramic materials, which provide face efects and details are stratified with the addi·
outstanding opalescence, translucence, and trans tion of low-fusing ceramic materialsJ-7 (Cerpress
parency. Indications for the current generation of all· Sensation SL, Leach & Dillon; IPS Empress, lvoclar
ceramic materials have expanded to include fixed Vivadent; Presskeramik Evopress. Wegold). Both
patial dentures and posterior restorations, with techniques require the creation of a master cast with
increasing esthetic and functional satisfaction. The removable dies and the preparation of a wax pattern
most popular material for all-ceramic restoration is a (Cerpress SL Carving Wax, Leach & Dillon), according
ceramic to which vitreous substances like leucite or to the technical principles previously discussed (see
hydroxyapatite have been added; the material also chapter 10) (Figs 11-39 to 11-41). Using the lost wax
contains oxides of aluminum, magnesium, or zirco· technique, the technician attaches sprue formers to
nium to augment the light refraction and hardness the wax pattern (Fig 11·42), invests the wax pattern,
Fig 1 1 -Jg Clinical situation requiring the esthetic restoration of two lateral incisors using pressable die-cast ceramic ICerpress SL).
of the material. Such ceramics are used in all types and finally, using the technique explained later in
Figs 11 -40 and 1 1 -41 Master cast and preparation of the d i es .
of restoration, from individual crowns to frameworks this chapter, heat-presses the ceramic. ,.
Fig 1 1-42 Copings are waxed and sprue formers attached in a manner similar to that used for metal casting.
CHAPTER 1 1
.. Ceramic material is available as colored pellets, restoration margins. Wax sprue formers are applied
called ceramic ingots, that are chosen for the color to the patterns (Fig 11·54), and, using an investment
and appearance they will impart to the definitive material (Creare Vest, Leach & Dillon) already pre·
restoration. The more opaque ingots are chosen for heated to 8so•c for so minutes, the casting ring is
darker cores, while the more transparent ingots are loaded with one or two ceramic ingots (based on
chosen for lighter cores. The ceramic structure is ere· wax weight and color) and positioned in the ceram·
ated inside a special kiln (Neytech CeramPress QEX, ics kiln. The ceramic is then heat-pressed.
Dentsply Ceramco) that melts the ceramic ingot at a When the cycle is completed, the technician must
temperature of 96o•c and injects it into a thermally wait until the end of slow cooling to remove the re·
pretreated casting ring at a pressure of 6 bars (Fig fractory material from the heat-pressed veneer, first
11-43). These operations must be performed with manually with a cutter (taking care not to damage
extreme precision and temperature control. After the veneers) and then with a sander loaded with 90·
removing the investment from the ceramic cast and mm glass spheres at 1.5 bars of pressure (Figs 11·55
cutting the sprue, the technician verifies the adap· to 11-58).
tation to the core and then applies ceramic material The last stages involve layering ceramic on the
(Figs 11·44 to 11·50) using the traditional stratifica· heat-pressed veneer (Fig 11·59) by using a compati·
tion process. ble ceramic with the same components and thermal
The heat-pressed all-ceramic technique can be expansion coeficient (14.6 to 14.8) as the ceramic
used to create porcelain laminate veneers, which are core. Dentin ceramic is applied to add greater chro·
preferable to traditional crowns for safeguarding healthy matic saturation, and finally, translucent and colored
dental structure and gingiva and guaranteeing the ceramics are applied at the incisal edge to give the
best esthetics.s-'0 When a highly esthetic anterior restoration high esthetic value and create a natural
restoration is required (Fig 11-51), a master cast with appearance (Figs 11-60 and 11-61). The restoration is
removable dies is used; the anatomic information that finished and polished. Because of the restoration's
is recorded for the gingiva is indispensable for improv· fragility, the authors use the microscope7 .9·" to give
ing the appearance of restorations (Fig 11-52). Wax the most precision and attention to the anatomic
patterns of the laminate veneers and full-coverage details and surface texture of the restoration (Fig II·
crowns are made with a special wax (Creare Wax, 62). After adhesive cementation, the definitive
Leach & Dillon) for heat-pressed ceramic (ig 11·53). restoration harmonizes perfectly with the patient's
The technician should follow the technique de natural dentition, thanks primarily to the technician's
scribed for metal-ceramic restorations, using the technique and the materials used (Figs n-63 to II·
microscope and taking care with the precision of 66). ..
Fig 1 1 -43 Copings are pressure die-cast with ceramic material. Figs 1 1 -44 and 11-45 Stratification and finishing of the crowns
using ceramics with a suitable thermal expansion coefficient. Figs 1 1 - 46 and 1 1 -47 Fin alization of the lateral incisor all
ceramic crowns. Figs 11-48 o 11-50 Definitive crowns after adhesive-type cementation. Esthetic integration with the natural
dentition is quite sa tis factory.
36 7
CHAPTER 1 1
.. Ceramic material is available as colored pellets, restoration margins. Wax sprue formers are applied
called ceramic ingots, that are chosen for the color to the patterns (Fig 11·54), and, using an investment
and appearance they will impart to the definitive material (Creare Vest, Leach & Dillon) already pre·
restoration. The more opaque ingots are chosen for heated to 8so•c for so minutes, the casting ring is
darker cores, while the more transparent ingots are loaded with one or two ceramic ingots (based on
chosen for lighter cores. The ceramic structure is ere· wax weight and color) and positioned in the ceram·
ated inside a special kiln (Neytech CeramPress QEX, ics kiln. The ceramic is then heat-pressed.
Dentsply Ceramco) that melts the ceramic ingot at a When the cycle is completed, the technician must
temperature of 96o•c and injects it into a thermally wait until the end of slow cooling to remove the re·
pretreated casting ring at a pressure of 6 bars (Fig fractory material from the heat-pressed veneer, first
11-43). These operations must be performed with manually with a cutter (taking care not to damage
extreme precision and temperature control. After the veneers) and then with a sander loaded with 90·
removing the investment from the ceramic cast and mm glass spheres at 1.5 bars of pressure (Figs 11·55
cutting the sprue, the technician verifies the adap· to 11-58).
tation to the core and then applies ceramic material The last stages involve layering ceramic on the
(Figs 11·44 to 11·50) using the traditional stratifica· heat-pressed veneer (Fig 11·59) by using a compati·
tion process. ble ceramic with the same components and thermal
The heat-pressed all-ceramic technique can be expansion coeficient (14.6 to 14.8) as the ceramic
used to create porcelain laminate veneers, which are core. Dentin ceramic is applied to add greater chro·
preferable to traditional crowns for safeguarding healthy matic saturation, and finally, translucent and colored
dental structure and gingiva and guaranteeing the ceramics are applied at the incisal edge to give the
best esthetics.s-'0 When a highly esthetic anterior restoration high esthetic value and create a natural
restoration is required (Fig 11-51), a master cast with appearance (Figs 11-60 and 11-61). The restoration is
removable dies is used; the anatomic information that finished and polished. Because of the restoration's
is recorded for the gingiva is indispensable for improv· fragility, the authors use the microscope7 .9·" to give
ing the appearance of restorations (Fig 11-52). Wax the most precision and attention to the anatomic
patterns of the laminate veneers and full-coverage details and surface texture of the restoration (Fig II·
crowns are made with a special wax (Creare Wax, 62). After adhesive cementation, the definitive
Leach & Dillon) for heat-pressed ceramic (ig 11·53). restoration harmonizes perfectly with the patient's
The technician should follow the technique de natural dentition, thanks primarily to the technician's
scribed for metal-ceramic restorations, using the technique and the materials used (Figs n-63 to II·
microscope and taking care with the precision of 66). ..
Fig 1 1 -43 Copings are pressure die-cast with ceramic material. Figs 1 1 -44 and 11-45 Stratification and finishing of the crowns
using ceramics with a suitable thermal expansion coefficient. Figs 1 1 - 46 and 1 1 -47 Fin alization of the lateral incisor all
ceramic crowns. Figs 11-48 o 11-50 Definitive crowns after adhesive-type cementation. Esthetic integration with the natural
dentition is quite sa tis factory.
36 7
CHAPTER 1 1
1 1 ·52
Fig 11-55 Pressure die-casting of the ceramic according to manufacturer recommendation. Figs 11-56 to 1 1 -58 Ceramic crown and veneers on
Fig 1 1 -51 Clinical situation requiring an esthetic anterior restoration. Fig 1 1 -52 A master cast is created for the construction of three veneers
the master dies. Note the marginal precision of the all-ceramic restorations. Fig 1 1 -59 Ceramic copings are checked on the master cast. Figs
and one crown in pressable die-cast ceramic. Fig 1 1 -53 Preliminary wax pattern on anterior teeth. This phase must never be omitted. espe
1 1 -60 and 1 1 -61 Stratification with low-fusing ceramic tCerpress Sensation SL).
cially when creating an esthetic restoration. Fig 1 1 -4 Wax sprue former prior to investment.
359
8
CHAPTER 1 1
1 1 ·52
Fig 11-55 Pressure die-casting of the ceramic according to manufacturer recommendation. Figs 11-56 to 1 1 -58 Ceramic crown and veneers on
Fig 1 1 -51 Clinical situation requiring an esthetic anterior restoration. Fig 1 1 -52 A master cast is created for the construction of three veneers
the master dies. Note the marginal precision of the all-ceramic restorations. Fig 1 1 -59 Ceramic copings are checked on the master cast. Figs
and one crown in pressable die-cast ceramic. Fig 1 1 -53 Preliminary wax pattern on anterior teeth. This phase must never be omitted. espe
1 1 -60 and 1 1 -61 Stratification with low-fusing ceramic tCerpress Sensation SL).
cially when creating an esthetic restoration. Fig 1 1 -4 Wax sprue former prior to investment.
359
8
CHAPTER 1 1
.. CAD/CAM TECH N O LOGY during the various laboratoy procedures. Compared

with other materials, zirconium demonstrates excel
lent physical and chemical characteristics') and has a
Config uring and executing prosthetic
lower density (6.o8 g/cml) than some gold a lloys (15
restorations
g/cml), which allows for lighter-weight restorations,
Research on restoration materials has gone hand in perhaps even half the weight of those made with tra
hand with the development of new technologies, and ditional metal-ceramic materials. At 2,700°C, its melt
general innovations in dentistry have changed -and ing point is much higher than the firing temperature
sometimes even revolutionized- standard laboratory for ceramic materials, which is important for stability
procedures. While CAM and CAD/CAM systems were of the restoration during ceramic stratiication. Its
used in various sectors of industrial production in the high flexion resistance (1,200 mPa) and its fracture
1970s, it was only in the 1990s that these systems resistance (ranging from 5 to 10 mPa, depending on
found application in dentistry. CAM systems use com specimen geometry) make this material ideal even for
puter technology to create the ceramic structure from posterior restorations, which are subject to heavy
the wax pattern made by the dental technician, while occlusal stress.•6
the CAD/CAM system combines computer-guided
configuration and execution of the restoration to
Mecha nical a n d manual stages
automate laboratoy procedures. The semi-inished .
of fabrication
result eliminates some procedures that the dental
technician normally performs manually.1·•s In the Clinical tooth preparation is the first step in the fab
context of the authors' laboratory experience, use of rication of a restoration, since the preparations must
a CAD/CAM system (Lava System, 3M ESPE) has been incline 4 degrees or more and have shoulders that
a true revolution that obliges dental technicians to are not too horizontal s degrees or more) to prevent
become familiar with concepts and steps that are scanning error. The preparations must not include
completely new to traditional laboratoy protocols. sharp angles (ie, no go-degree shoulder finish line
designs), but must be rounded. A correct precision
impression (Figs 11-67 and n-68) is indispensable for
Zirco n i u m oxide
creating a traditional light-colored master cast i n type
CAD/CAM technology, which replaces the manual IV plaster or polyurethane resin with all of the details
modeling and casting of the crowns, also requires the of the clinical situation.'l An undercut of 1.0 to 1.5
use of a diferent material, zirconium oxide (ZrO,). mm is made apical to the preparation margin to fa cil
The important characteristics of this silver-white itate computerized scanning of the finish line (Figs
metal are its hardness, esthetics, and above all its 11-69 and 11-70). Unlike metal-ceramic preparation,
proven biocompatibility through its widespread use no hardeners or spacer lacquers have to be applied
in coxofemural joint prostheses. The zirconium oxide prior to waxup because the software cannot read
used in dentisty is partially stabilized with yttrium shiny zones and automatically allows space for
oxide (TZP) to enhance the material's mechanical cementation (Fig 11-71). The Lava system scanner
Fig 1 1 -62 Finalization and polishing of the ceramic restorations on the master cast. uses triangulated optics that record the contours of ..
properties and to prevent the formation of cracks
Figs 1 1 -63 to 1 1 -66 Different views of the of the definitive restoration in situ. The good marginal integration and excellent esthetics are com
bined with resistance greater than that of feldspathic ceramics.
61
CHAPTER 1 1
.. CAD/CAM TECH N O LOGY during the various laboratoy procedures. Compared

with other materials, zirconium demonstrates excel
lent physical and chemical characteristics') and has a
Config uring and executing prosthetic
lower density (6.o8 g/cml) than some gold a lloys (15
restorations
g/cml), which allows for lighter-weight restorations,
Research on restoration materials has gone hand in perhaps even half the weight of those made with tra
hand with the development of new technologies, and ditional metal-ceramic materials. At 2,700°C, its melt
general innovations in dentistry have changed -and ing point is much higher than the firing temperature
sometimes even revolutionized- standard laboratory for ceramic materials, which is important for stability
procedures. While CAM and CAD/CAM systems were of the restoration during ceramic stratiication. Its
used in various sectors of industrial production in the high flexion resistance (1,200 mPa) and its fracture
1970s, it was only in the 1990s that these systems resistance (ranging from 5 to 10 mPa, depending on
found application in dentistry. CAM systems use com specimen geometry) make this material ideal even for
puter technology to create the ceramic structure from posterior restorations, which are subject to heavy
the wax pattern made by the dental technician, while occlusal stress.•6
the CAD/CAM system combines computer-guided
configuration and execution of the restoration to
Mecha nical a n d manual stages
automate laboratoy procedures. The semi-inished .
of fabrication
result eliminates some procedures that the dental
technician normally performs manually.1·•s In the Clinical tooth preparation is the first step in the fab
context of the authors' laboratory experience, use of rication of a restoration, since the preparations must
a CAD/CAM system (Lava System, 3M ESPE) has been incline 4 degrees or more and have shoulders that
a true revolution that obliges dental technicians to are not too horizontal s degrees or more) to prevent
become familiar with concepts and steps that are scanning error. The preparations must not include
completely new to traditional laboratoy protocols. sharp angles (ie, no go-degree shoulder finish line
designs), but must be rounded. A correct precision
impression (Figs 11-67 and n-68) is indispensable for
Zirco n i u m oxide
creating a traditional light-colored master cast i n type
CAD/CAM technology, which replaces the manual IV plaster or polyurethane resin with all of the details
modeling and casting of the crowns, also requires the of the clinical situation.'l An undercut of 1.0 to 1.5
use of a diferent material, zirconium oxide (ZrO,). mm is made apical to the preparation margin to fa cil
The important characteristics of this silver-white itate computerized scanning of the finish line (Figs
metal are its hardness, esthetics, and above all its 11-69 and 11-70). Unlike metal-ceramic preparation,
proven biocompatibility through its widespread use no hardeners or spacer lacquers have to be applied
in coxofemural joint prostheses. The zirconium oxide prior to waxup because the software cannot read
used in dentisty is partially stabilized with yttrium shiny zones and automatically allows space for
oxide (TZP) to enhance the material's mechanical cementation (Fig 11-71). The Lava system scanner
Fig 1 1 -62 Finalization and polishing of the ceramic restorations on the master cast. uses triangulated optics that record the contours of ..
properties and to prevent the formation of cracks
Figs 1 1 -63 to 1 1 -66 Different views of the of the definitive restoration in situ. The good marginal integration and excellent esthetics are com
bined with resistance greater than that of feldspathic ceramics.
61
CHAPTER 1 1
. the preparation, including borders, without contact cooling, the coping contracts, returning to its real
with the object. dimensions (Figs 11-75 and 11·76).
When the saw-cut cast is scanned, whether for a The final stage consists of verifying the adapta·
single crown or a (maximum four-unit) fixed partial, lion of the si ntered zirconium coping to the master
the CAD system processes a three-dimensional image die, with particular attention to the stability and pre·
on the monitor, which is then examined and modified cision of the margin (Figs 11-77 and 11-78). The mar·
as necessary (eg, to provide space for cementation). gina\ contour is finished with a fine-grit diamond bur
For fixed partial dentures, the connections between (88s6.314.016, Komet), working at high magnification
the units can also be studied and modified on the under the microscope and attempting to improve the
screen, using a database system, which contains var· shape of the crown profile both horizontally and ver·
ious possibilities for realizing a suitable framework tically (Figs 11-79 to 11-81).
design (Figs 11-72 and 11-73). The CAM system auto· The technician may adopt the micromargin tech·
mates prosthetic creation by milling raw, presintered nique used on metal-ceramic restorations, which ofers
zirconium oxide using the trajectories calculated in distinct esthetic advantages. For example, the absence
the CAD. of metal results in greater translucence at the margin.
i
Zirconium is softer before sintering, which facili· In addition, since the ceramic veneer has a low melt· C•
tates fabrication by shortening milling times, reduc· ing point, the risk of undesired distortions at the mar·
ing wear on instruments, and increasing precision. gin is significantly reduced. With silicon carbide burs
The clinician can modify the shape of the structure
before sintering using silicone points designed for
it is possible to finish the external surface of the cop·
ing, preparing it to accept the veneering ceramic (Lava
()
ceramic materials (Fig 11-74). Once the structure is Ceram, 3M ESPE) that is compatible with the Lava
ready for sintering, it is immersed in a liquid dye System, and complete the restoration with enhanced
(Lava Frame Shade, 3M ESPE) for about 2 minutes to esthetics and function (Figs 11-82 to 11·85).
acquire the color that corresponds to the natural Zirconium can be used for numerous restorative
dentition; only after this treatment can the frame be needs and combines excellent esthetics with a high
sintered. Sintering will shrink the restorations by a resistance to occlusal force. It can be employed both
total of 18% to 25%; however, this is factored into in the lateral areas. for patients with high esthetic
the design: The computer automatically oversizes the expectations, and in the anterior dentition to replace
contour of the restoration to allow the Lava System traditional metal-ceramic fixed partial dentures for
to maintain dimensional precision. The sintering pro· edentulous cases limited to one or two teeth (Figs
cess lasts 7 hours and is performed at 1,6oo•c; after 11-86 to 11-118). •
Figs 11-67 and 1 1 -68 Precision impression and detail of the finish line. Fig 1 1 -6g Preparation of the master die with a round diamond bur. An
undercut is created apical to the preparation to expose the finish line. Fig 11-70 Restoration margin marked with a crayo � . Fig 1 1 -71 Master
die prepared for scanning. Hardening or spac � r lacquers are not used because they would Interfere w1th computer scann1ng. F1g 11-72 Raw.
presinlered zirconium oxide. F1g 1 1 -73 Companson of preSintered and s1ntered structures for a fixed part1al denture.
42
CHAPTER 1 1
. the preparation, including borders, without contact cooling, the coping contracts, returning to its real
with the object. dimensions (Figs 11-75 and 11·76).
When the saw-cut cast is scanned, whether for a The final stage consists of verifying the adapta·
single crown or a (maximum four-unit) fixed partial, lion of the si ntered zirconium coping to the master
the CAD system processes a three-dimensional image die, with particular attention to the stability and pre·
on the monitor, which is then examined and modified cision of the margin (Figs 11-77 and 11-78). The mar·
as necessary (eg, to provide space for cementation). gina\ contour is finished with a fine-grit diamond bur
For fixed partial dentures, the connections between (88s6.314.016, Komet), working at high magnification
the units can also be studied and modified on the under the microscope and attempting to improve the
screen, using a database system, which contains var· shape of the crown profile both horizontally and ver·
ious possibilities for realizing a suitable framework tically (Figs 11-79 to 11-81).
design (Figs 11-72 and 11-73). The CAM system auto· The technician may adopt the micromargin tech·
mates prosthetic creation by milling raw, presintered nique used on metal-ceramic restorations, which ofers
zirconium oxide using the trajectories calculated in distinct esthetic advantages. For example, the absence
the CAD. of metal results in greater translucence at the margin.
i
Zirconium is softer before sintering, which facili· In addition, since the ceramic veneer has a low melt· C•
tates fabrication by shortening milling times, reduc· ing point, the risk of undesired distortions at the mar·
ing wear on instruments, and increasing precision. gin is significantly reduced. With silicon carbide burs
The clinician can modify the shape of the structure
before sintering using silicone points designed for
it is possible to finish the external surface of the cop·
ing, preparing it to accept the veneering ceramic (Lava
()
ceramic materials (Fig 11-74). Once the structure is Ceram, 3M ESPE) that is compatible with the Lava
ready for sintering, it is immersed in a liquid dye System, and complete the restoration with enhanced
(Lava Frame Shade, 3M ESPE) for about 2 minutes to esthetics and function (Figs 11-82 to 11·85).
acquire the color that corresponds to the natural Zirconium can be used for numerous restorative
dentition; only after this treatment can the frame be needs and combines excellent esthetics with a high
sintered. Sintering will shrink the restorations by a resistance to occlusal force. It can be employed both
total of 18% to 25%; however, this is factored into in the lateral areas. for patients with high esthetic
the design: The computer automatically oversizes the expectations, and in the anterior dentition to replace
contour of the restoration to allow the Lava System traditional metal-ceramic fixed partial dentures for
to maintain dimensional precision. The sintering pro· edentulous cases limited to one or two teeth (Figs
cess lasts 7 hours and is performed at 1,6oo•c; after 11-86 to 11-118). •
Figs 11-67 and 1 1 -68 Precision impression and detail of the finish line. Fig 1 1 -6g Preparation of the master die with a round diamond bur. An
undercut is created apical to the preparation to expose the finish line. Fig 11-70 Restoration margin marked with a crayo � . Fig 1 1 -71 Master
die prepared for scanning. Hardening or spac � r lacquers are not used because they would Interfere w1th computer scann1ng. F1g 11-72 Raw.
presinlered zirconium oxide. F1g 1 1 -73 Companson of preSintered and s1ntered structures for a fixed part1al denture.
42
CHAPTER 1 1
Fig 11-74 Presintered structure finished with a silicone point designed for use with ceramics. Fig 1 1 -75 The size of the coping is reduced by Figs 1 1 -80 and 1 1 -81 At 32 x magnification. the marginal adaptation appears very precise. Fig 1 1 -82 Stratification of the coping with lava
20% during the sintering phase. Fig 1 1 -76 Zirconium coping positioned on the master cast. Fig 1 1 -77 To improve marginal adaptation. the inte ceramic. Fig 1 1 -83 Excellent precision is apparent in the definitive crown on the master die. Figs 1 1 -B4and 11-85 Crown on the master die after
rior of the structure is touched up. as evidenced by the highlighting lacquer. Fig 1 1 -78 Shape of the crown is refined with a coarse-grit dia finalization of the ceramic coating.
mond bur. Fig 11-79 With a fine-grit bur. the restoration margin is prepared with a design similar to the counter-chamfer used for the cermet
crown.
45
CHAPTER 1 1
Fig 11-74 Presintered structure finished with a silicone point designed for use with ceramics. Fig 1 1 -75 The size of the coping is reduced by Figs 1 1 -80 and 1 1 -81 At 32 x magnification. the marginal adaptation appears very precise. Fig 1 1 -82 Stratification of the coping with lava
20% during the sintering phase. Fig 1 1 -76 Zirconium coping positioned on the master cast. Fig 1 1 -77 To improve marginal adaptation. the inte ceramic. Fig 1 1 -83 Excellent precision is apparent in the definitive crown on the master die. Figs 1 1 -B4and 11-85 Crown on the master die after
rior of the structure is touched up. as evidenced by the highlighting lacquer. Fig 1 1 -78 Shape of the crown is refined with a coarse-grit dia finalization of the ceramic coating.
mond bur. Fig 11-79 With a fine-grit bur. the restoration margin is prepared with a design similar to the counter-chamfer used for the cermet
crown.
45
CHAPTER 1 1
Figs 11-86 and 1 1-87 Tooth preparation and definitive all-ceramic restoration after cementation with a resinous cement. Fig 1 1 -88 Tooth prepa Figs 1 1 - gJ and 1 1 -g4 Restorations after layering with a zirconium-compatible ceramic. Note the excellent shine and high level of precision.
ration for Lava CAD/CAM scanning must eschew evident corners and have shoulder margins at least 5 degrees superior to the horizontal Both aspects favor the good integration of the restoration and continued periodontal health. Fig 1 1 - gs Profile of the ceramic- layered restora
plane. Thus. rounded shoulder or g O-degree shoulder preparations should b e avoided. Figs 1 1 -8g and 11-go A young patient required prosthet tion on the master cast shows excellent adaptation at the margin that integrates with the intact tooth structure apical to the preparation tine.
i c restoration after endodontic therapy and periodontal regeneration. Two clinical views show adequate preparations and intrasulcular mar Fig 1 1 - g6 Interior of the molar restoration after ceramic application. The zirconium substructure is distinguishable in color from the ceramic
gins. figs 1 1 -g l and 1 1 -g2 O c clusal and lateral views of zirconium copings on the maxillary left second premolar and first molar. layer and shows that the margin i s entirely in zirconium. Fig 11- g7 Finished and polished restoration on the cast.
6 67
CHAPTER 1 1
Figs 11-86 and 1 1-87 Tooth preparation and definitive all-ceramic restoration after cementation with a resinous cement. Fig 1 1 -88 Tooth prepa Figs 1 1 - gJ and 1 1 -g4 Restorations after layering with a zirconium-compatible ceramic. Note the excellent shine and high level of precision.
ration for Lava CAD/CAM scanning must eschew evident corners and have shoulder margins at least 5 degrees superior to the horizontal Both aspects favor the good integration of the restoration and continued periodontal health. Fig 1 1 - gs Profile of the ceramic- layered restora
plane. Thus. rounded shoulder or g O-degree shoulder preparations should b e avoided. Figs 1 1 -8g and 11-go A young patient required prosthet tion on the master cast shows excellent adaptation at the margin that integrates with the intact tooth structure apical to the preparation tine.
i c restoration after endodontic therapy and periodontal regeneration. Two clinical views show adequate preparations and intrasulcular mar Fig 1 1 - g6 Interior of the molar restoration after ceramic application. The zirconium substructure is distinguishable in color from the ceramic
gins. figs 1 1 -g l and 1 1 -g2 O c clusal and lateral views of zirconium copings on the maxillary left second premolar and first molar. layer and shows that the margin i s entirely in zirconium. Fig 11- g7 Finished and polished restoration on the cast.
6 67
CHAPTER 1
partial denture on the cast. which shows the marginal closure lthe lighter-colored area) entirely in zirconium. Fig 11-105 Marginal precision
Fig H-98 Finished and polished restoration in situ following cementation with resinous cement. Fig H-99 Occlusal view. Note the chromatic of the fixed partial denture on the plaster cast. Fig 11-106 Occlusal view of restorations on the working cast. Fig 1 1 -107 Functional view of the
d � monance of the restoratoons compared to the natural maxillary first premolar. This can be attributed to a higher index of light refraction fixed partial denture and two mandibular molar restorations. made with lava CAO/CAM technology. showing interarch ratios. Figs n-108 and
_
woth a zorconoum substrate. Fig H-100 Comparoson of an extracted natural tooth and a restoration with a ceramic layer on a zirconium sub 11-10g Four zirconium copings during clinical adaptation. at medium and high magnification. The authors wished to investigate the highest
strate. Note the dofferent refracto.on ondoc � s. Fig 11-101 . Polyether impression of a maxillary left fixed partial denture that was planned to precision possible in marginal adaptation in a clinical study of 1 8 specimens of extracted teeth prepared for the purpose.
replace the mossong tooth woth a son ! le-unot restorahon on zorconoum. Fig 1 1-102 Resin model left uncut and unseparated to prevent movements
that could compromiSe adaptatoon _ on the mouth. The zirconium structure is shown prior to adaptation and marginal finishing. Fig 11-103
Restoratoon margon fonoshed woth coarse-grot doamond burs. Fig n -104 Restoration after ceramic application. Note the adaptation of the fixed
U!
CHAPTER 1
partial denture on the cast. which shows the marginal closure lthe lighter-colored area) entirely in zirconium. Fig 11-105 Marginal precision
Fig H-98 Finished and polished restoration in situ following cementation with resinous cement. Fig H-99 Occlusal view. Note the chromatic of the fixed partial denture on the plaster cast. Fig 11-106 Occlusal view of restorations on the working cast. Fig 1 1 -107 Functional view of the
d � monance of the restoratoons compared to the natural maxillary first premolar. This can be attributed to a higher index of light refraction fixed partial denture and two mandibular molar restorations. made with lava CAO/CAM technology. showing interarch ratios. Figs n-108 and
_
woth a zorconoum substrate. Fig H-100 Comparoson of an extracted natural tooth and a restoration with a ceramic layer on a zirconium sub 11-10g Four zirconium copings during clinical adaptation. at medium and high magnification. The authors wished to investigate the highest
strate. Note the dofferent refracto.on ondoc � s. Fig 11-101 . Polyether impression of a maxillary left fixed partial denture that was planned to precision possible in marginal adaptation in a clinical study of 1 8 specimens of extracted teeth prepared for the purpose.
replace the mossong tooth woth a son ! le-unot restorahon on zorconoum. Fig 1 1-102 Resin model left uncut and unseparated to prevent movements
that could compromiSe adaptatoon _ on the mouth. The zirconium structure is shown prior to adaptation and marginal finishing. Fig 11-103
Restoratoon margon fonoshed woth coarse-grot doamond burs. Fig n -104 Restoration after ceramic application. Note the adaptation of the fixed
U!
1 1-1 1 1
1 1-1 1 3
Figs 11-110 and 11-111 During this clinical research. the authors prepared 1 8 molars. extracted for periodontal reasons. with a long chamfer Fig 1 1 -114 Ceramic-coated zirconium restoration at 25x magnification. showing the transition point between the restoration and the extract
finish line. subsequently took an imipression with polyether material. and then developed a cast i n polyurethane resin because of the mate ed tooth. The human factor. defined as accurate procedures performed using appropriate magnification systems. has made it possible to
rial's higher resistance to abrasion and wear during mechanical procedures. The long chamfer finish line design aids CAD/CAM scanning. obtain results of extremely high precision. Fig 1 1 -115 After cementation. the restoration is sectioned and analyzed with a polarized micro
Figs 11-112 and 1 1 -11J in the authors' opinion. the "human factor." even in procedures where machine should replace man. is very important. scope. The layers of fixative cement. zirconium. and ceramic are visible. Figs 11-116 and 11-117 At S O x magnification. these two specimens
Procedures like surface preparation. cast fabrication in polyurethane resin. and adaptation and refinement of the presintered zirconium can demonstrate the possible degree of precision that can be achieved if a dental technician works skillfully and accuralley. Fig 11-118 At 1 0 0 x
significantly influence the adaptation and precision. A human hair is used to show the the level of precision that can be reached when the magnification. the intimate contact and marginal adaptation after cementation are evident. From the statistical analysis o f 1 8 specimens ana
human factor in the procedures is duly considered. lyzed after cementation and sectioning. the average values ranged from 20 to 30 �m. This result shows the CAD/CAM system to offer the high
est degree of precision.
0 371
1 1-1 1 1
1 1-1 1 3
Figs 11-110 and 11-111 During this clinical research. the authors prepared 1 8 molars. extracted for periodontal reasons. with a long chamfer Fig 1 1 -114 Ceramic-coated zirconium restoration at 25x magnification. showing the transition point between the restoration and the extract
finish line. subsequently took an imipression with polyether material. and then developed a cast i n polyurethane resin because of the mate ed tooth. The human factor. defined as accurate procedures performed using appropriate magnification systems. has made it possible to
rial's higher resistance to abrasion and wear during mechanical procedures. The long chamfer finish line design aids CAD/CAM scanning. obtain results of extremely high precision. Fig 1 1 -115 After cementation. the restoration is sectioned and analyzed with a polarized micro
Figs 11-112 and 1 1 -11J in the authors' opinion. the "human factor." even in procedures where machine should replace man. is very important. scope. The layers of fixative cement. zirconium. and ceramic are visible. Figs 11-116 and 11-117 At S O x magnification. these two specimens
Procedures like surface preparation. cast fabrication in polyurethane resin. and adaptation and refinement of the presintered zirconium can demonstrate the possible degree of precision that can be achieved if a dental technician works skillfully and accuralley. Fig 11-118 At 1 0 0 x
significantly influence the adaptation and precision. A human hair is used to show the the level of precision that can be reached when the magnification. the intimate contact and marginal adaptation after cementation are evident. From the statistical analysis o f 1 8 specimens ana
human factor in the procedures is duly considered. lyzed after cementation and sectioning. the average values ranged from 20 to 30 �m. This result shows the CAD/CAM system to offer the high
est degree of precision.
0 371
CHAPTER 1 1
R E FE R E N CES 6. Yamamoto M. etal-Ceramics. Chicago: Quintessence, 11. Battaini P, Terranova M. Captek-Una \ega composita di 4. Kelly JR. Nishimura I, campbell SO. Ceramics in dentisty:
1985. nuova concezione per metallo·cerami.a. Quintessenza Historical roots and current perspectives. J Prosthet Dent
1. Kuwata M. Theory and Practice for Ceramo·etal Restor· 7• clean JW. The Science and t of Dental Ceramics, vols Odontotecnica 1994;9:883-889. 1996;75:18-}2.
ations. Chicago: Quintessence, 198o. 1 and 2. Chicago: Quintessence. 1980. 12. Shoher I, Whiteman A. Captek-A new capillary tech· 15. Eichner IK, Kappert HF. Zahn�rztliche Wekstofe und
2. assironi D, Battistelli . Pascetta R. a Precisione Nella 8. Wataha JC, Lewis JB. Lockwood PE, Rakich DR. Efect of nology for ceramometal restoration. Quintessence lnt ihre Verarbeitung. Heidelberg: Huthig, 1996.
Restaurazione Protesica. Verona: Resch. 1993. dental metal ions on glutathione levels in THP-t human 1995;18:9-20. 16. Witkowski 5. Ceramiche per pressofusione: Panoramica
J. ccabe I. Applied Dental aterials. London: Blackwell, monocytes. I Oral Rehabil 200;27:5-516. 13. Shoher I. Vital tooth esthetics in captek restorations. aggiomata dei sistemi del 2XI. Quintessenza Odont·
1985. 9· Wataha JC. Biocompatibility of dental casting alloys: A Dent Clin North Am 1998;42:713-718. otecnica 201;2:1-147·
4· Phillips RW. Skinne(s Science of Dental aterials, ed 9· review. I Prosthet Dent 200;8J:22J-234·
Philadelphia: Saunders, 1991. to. artignoni M, Schonenberger J. Precisione e contomo
5· Garber DA, Adar P, Goldstein RE, Salama H. Alia ricerca nella ricostruzione protesica. Berlin: Quintessenz, 1987.
della corona perfetta in ceramka integrate. Quintessenza
Odontotecnica 2001;57'35J-J61.
m
m
CHAPTER 1 1
R E FE R E N CES 6. Yamamoto M. etal-Ceramics. Chicago: Quintessence, 11. Battaini P, Terranova M. Captek-Una \ega composita di 4. Kelly JR. Nishimura I, campbell SO. Ceramics in dentisty:
1985. nuova concezione per metallo·cerami.a. Quintessenza Historical roots and current perspectives. J Prosthet Dent
1. Kuwata M. Theory and Practice for Ceramo·etal Restor· 7• clean JW. The Science and t of Dental Ceramics, vols Odontotecnica 1994;9:883-889. 1996;75:18-}2.
ations. Chicago: Quintessence, 198o. 1 and 2. Chicago: Quintessence. 1980. 12. Shoher I, Whiteman A. Captek-A new capillary tech· 15. Eichner IK, Kappert HF. Zahn�rztliche Wekstofe und
2. assironi D, Battistelli . Pascetta R. a Precisione Nella 8. Wataha JC, Lewis JB. Lockwood PE, Rakich DR. Efect of nology for ceramometal restoration. Quintessence lnt ihre Verarbeitung. Heidelberg: Huthig, 1996.
Restaurazione Protesica. Verona: Resch. 1993. dental metal ions on glutathione levels in THP-t human 1995;18:9-20. 16. Witkowski 5. Ceramiche per pressofusione: Panoramica
J. ccabe I. Applied Dental aterials. London: Blackwell, monocytes. I Oral Rehabil 200;27:5-516. 13. Shoher I. Vital tooth esthetics in captek restorations. aggiomata dei sistemi del 2XI. Quintessenza Odont·
1985. 9· Wataha JC. Biocompatibility of dental casting alloys: A Dent Clin North Am 1998;42:713-718. otecnica 201;2:1-147·
4· Phillips RW. Skinne(s Science of Dental aterials, ed 9· review. I Prosthet Dent 200;8J:22J-234·
Philadelphia: Saunders, 1991. to. artignoni M, Schonenberger J. Precisione e contomo
5· Garber DA, Adar P, Goldstein RE, Salama H. Alia ricerca nella ricostruzione protesica. Berlin: Quintessenz, 1987.
della corona perfetta in ceramka integrate. Quintessenza
Odontotecnica 2001;57'35J-J61.
m
m
C H A P T E R 1 2
E S T H E T I C C O N S I D E RAT I O N S
F O R C ERAM I C RE S T O RAT I O NS
C
eramic is widely acknowledged to be the most diferently to light than does a natural tooth; there·
reliable material for esthetics and functional fore, the technician must learn to handle the materi
long-term restorative treatment. As a general al with considerable skill and expertise, especially
rule, the definitive restoration replicates the shape of since the final chromatic shade of the ceramic
the provisional restoration (sometimes with small becomes certain only after firing. Technicians also
changes) and the structure and substance of a nat must study the interactions between color and trans
ural tooth as closely as possible. However, ceramic parency to be able to successfully imitate nature.'-S
Fig 12-1 Refraction. rellection. and light transmission of natural teeth
does not posess the same characteristics as natural Today, patients demand greater esthetics. Dental
teeth, exhibiting significant limitations i n structure. technicians must accurately define the inal color and
color, and surface texture. These diferences require transparency of their materials in advance. Through
the dental ceramist to develop significant skill and careful observation of the human dentition, the tech
in-depth knowledge of ceramic material to achieve nician can consider the four esthetic facets of natur
the most natural-looking restorations. Simulation of al teeth: gradation, brilliance, saturation, and trans
natural teeth cannot be implemented by using only parency.6 While transparency is considered the fourth
three or four ceramic layers; the d i fficult and time facet, it influences every other esthetic component
consuming process of ceramic stratification requires since it determines the amount of light that can pass
the ceramist to expetly arrange many layers of through the teeth. Analysis against a black back· . with enamel and transparent layers. The efect is impossible to achieve using the more traditional
ceramic material. ground must be made to understand better the a progression from a high degree of opacity at the technique.
In this last esthetic phase of restoration, the clin transparency of each tooth or restoration (Fig 12-1). center to absence of opacity at the exterior. In this
ician and the ceramist must work together to meet Brilliance, which is a direct function of transparency, consistent and orderly stratiication, each new layer Using the second technique, there may be areas
the patient's expectations before the restoration is varies depending on the use of a white or black is less opaque than the underlying layer (Fig 12-2). where an opaque layer is applied after a less
cemented and the treatment is completed. background. 2. Orderly disordered stratiication: Ceramic is lay opaque layer, or where a more transparent layer lies
There are two diferent approaches to the ceram ered in a more nuanced fashion. The technician below a less transparent layer (Fig 12-3). The light
again starts with maximum opacity at the interior efects change substantially i n such areas, since a
ic stratification process:
and gradually introduces layers with no opacity greater amount of light is reflected or absorbed by
STRATI F I CATIO N . LIG HT.
and high translucence_?-" However, transparent the ceramic material, which enhances the perceived
A N D COLO R 1. Orderly stratiication: Ceramic is layered in a pre
cise order to simulate dental structures. The strat layers and layers of superficial color are alter depth of the restoration. Transparency lies under
nated with layers of dentin and enamel materials rather than above an enamel layer, causing light to
Dental technicians understand that when teeth are ification process begins with an opaque dentin,
to create natural light efects that would be distribute throughout the crown. ,.
restored using ceramic, the restorative material reacts continues with a less opaque dentin, and finishes .
C H A P T E R 1 2
E S T H E T I C C O N S I D E RAT I O N S
F O R C ERAM I C RE S T O RAT I O NS
C
eramic is widely acknowledged to be the most diferently to light than does a natural tooth; there·
reliable material for esthetics and functional fore, the technician must learn to handle the materi
long-term restorative treatment. As a general al with considerable skill and expertise, especially
rule, the definitive restoration replicates the shape of since the final chromatic shade of the ceramic
the provisional restoration (sometimes with small becomes certain only after firing. Technicians also
changes) and the structure and substance of a nat must study the interactions between color and trans
ural tooth as closely as possible. However, ceramic parency to be able to successfully imitate nature.'-S
Fig 12-1 Refraction. rellection. and light transmission of natural teeth
does not posess the same characteristics as natural Today, patients demand greater esthetics. Dental
teeth, exhibiting significant limitations i n structure. technicians must accurately define the inal color and
color, and surface texture. These diferences require transparency of their materials in advance. Through
the dental ceramist to develop significant skill and careful observation of the human dentition, the tech
in-depth knowledge of ceramic material to achieve nician can consider the four esthetic facets of natur
the most natural-looking restorations. Simulation of al teeth: gradation, brilliance, saturation, and trans
natural teeth cannot be implemented by using only parency.6 While transparency is considered the fourth
three or four ceramic layers; the d i fficult and time facet, it influences every other esthetic component
consuming process of ceramic stratification requires since it determines the amount of light that can pass
the ceramist to expetly arrange many layers of through the teeth. Analysis against a black back· . with enamel and transparent layers. The efect is impossible to achieve using the more traditional
ceramic material. ground must be made to understand better the a progression from a high degree of opacity at the technique.
In this last esthetic phase of restoration, the clin transparency of each tooth or restoration (Fig 12-1). center to absence of opacity at the exterior. In this
ician and the ceramist must work together to meet Brilliance, which is a direct function of transparency, consistent and orderly stratiication, each new layer Using the second technique, there may be areas
the patient's expectations before the restoration is varies depending on the use of a white or black is less opaque than the underlying layer (Fig 12-2). where an opaque layer is applied after a less
cemented and the treatment is completed. background. 2. Orderly disordered stratiication: Ceramic is lay opaque layer, or where a more transparent layer lies
There are two diferent approaches to the ceram ered in a more nuanced fashion. The technician below a less transparent layer (Fig 12-3). The light
again starts with maximum opacity at the interior efects change substantially i n such areas, since a
ic stratification process:
and gradually introduces layers with no opacity greater amount of light is reflected or absorbed by
STRATI F I CATIO N . LIG HT.
and high translucence_?-" However, transparent the ceramic material, which enhances the perceived
A N D COLO R 1. Orderly stratiication: Ceramic is layered in a pre
cise order to simulate dental structures. The strat layers and layers of superficial color are alter depth of the restoration. Transparency lies under
nated with layers of dentin and enamel materials rather than above an enamel layer, causing light to
Dental technicians understand that when teeth are ification process begins with an opaque dentin,
to create natural light efects that would be distribute throughout the crown. ,.
restored using ceramic, the restorative material reacts continues with a less opaque dentin, and finishes .
CHAPTER 1 2
Esthetic Considerations for Ceramic Restorations
I I :1
.. The technician also must be familiar with the con a low value has more black. The term chroma .. these variables. together with other atmospheric uration, and brilliance (Figs 12-7 and 12·8). Finally,
cepts of hue, value, and chroma. The term hue•J is describes the color's purity and degree of intensity conditions, influence perceived color. Natural light position relative to the light source and its angle of
synonymous with color and expresses the qualita or saturation. also varies depending on the sun's position during incidence also can change color saturation.
tive variation, namely, the quality that diferentiates Color is best observed in direct sunlight. When the day and on the inclination of the sun's rays (Figs
an orange color from a green color. Hue can vary sunlight comes into contact with particles suspend 12-4 to 12-6).
Opalescence
depending on the background or adjacent colors, or ed in the air, it is refracted differently depending on Color perception is influenced by surface quality,
the effect of natural or artificial light, which varies at the density and diameter of the particles and under which can change the distribution of the luminous The term opalescence describes the capacity of an
diferent times of the day or under diferent weath goes many changes i n speed, difusion, and direc flux and consequently the reflected light. In addi object, such as a tooth, to appear orange when back-
er conditions. The term value describes the relative tion. Light with a very long wavelength is stronger tion, the size of a surface can modify the degree of lit and milky blue when lit from the front or the side
lightness or darkness of hue-in other words, the and subject to less refraction than light with a short saturation and therefore alter the intensity of a and set against a dark background. Opalescence
amount of gray in a color. This term expresses the wavelength. The irregular nature of light difusion, given color. The shape of an object, whether flat or occurs in the enamel layer and can be compared to
color's relationship with white and black; a color reflection, refraction, and dispersion is inluenced by curved, has a signiicant influence on the light distri· the light efects of the setting and rising sun that
with a high value has more white and a color with the characteristics of the suspended particles, and .. bution, which also causes changes in hue, color sat· create orange coloring (Figs 12-9 to 12-11). As light ..
Fig 12-2 Orderly stratification scheme. This static technique lacks contrast and results in an artificial appearance when com
pared w1th natural teeth. Fig 12-3 Orderly disordered stratification scheme. This solution has opaque layers over the translu
cent layers and transparent effects under the translucent layers. which results in a more natural and tooth-like restoration.
77
ll
CHAPTER 1 2
I I :1
.. The technician also must be familiar with the con a low value has more black. The term chroma .. these variables. together with other atmospheric uration, and brilliance (Figs 12-7 and 12·8). Finally,
cepts of hue, value, and chroma. The term hue•J is describes the color's purity and degree of intensity conditions, influence perceived color. Natural light position relative to the light source and its angle of
synonymous with color and expresses the qualita or saturation. also varies depending on the sun's position during incidence also can change color saturation.
tive variation, namely, the quality that diferentiates Color is best observed in direct sunlight. When the day and on the inclination of the sun's rays (Figs
an orange color from a green color. Hue can vary sunlight comes into contact with particles suspend 12-4 to 12-6).
Opalescence
depending on the background or adjacent colors, or ed in the air, it is refracted differently depending on Color perception is influenced by surface quality,
the effect of natural or artificial light, which varies at the density and diameter of the particles and under which can change the distribution of the luminous The term opalescence describes the capacity of an
diferent times of the day or under diferent weath goes many changes i n speed, difusion, and direc flux and consequently the reflected light. In addi object, such as a tooth, to appear orange when back-
er conditions. The term value describes the relative tion. Light with a very long wavelength is stronger tion, the size of a surface can modify the degree of lit and milky blue when lit from the front or the side
lightness or darkness of hue-in other words, the and subject to less refraction than light with a short saturation and therefore alter the intensity of a and set against a dark background. Opalescence
amount of gray in a color. This term expresses the wavelength. The irregular nature of light difusion, given color. The shape of an object, whether flat or occurs in the enamel layer and can be compared to
color's relationship with white and black; a color reflection, refraction, and dispersion is inluenced by curved, has a signiicant influence on the light distri· the light efects of the setting and rising sun that
with a high value has more white and a color with the characteristics of the suspended particles, and .. bution, which also causes changes in hue, color sat· create orange coloring (Figs 12-9 to 12-11). As light ..
Fig 12-2 Orderly stratification scheme. This static technique lacks contrast and results in an artificial appearance when com
pared w1th natural teeth. Fig 12-3 Orderly disordered stratification scheme. This solution has opaque layers over the translu
cent layers and transparent effects under the translucent layers. which results in a more natural and tooth-like restoration.
77
ll
CHAPTER 1 2
L I G H T I N D I F F E R E N T E N V I R O N M E N TA L C O N D I T I O N S
. passes through a tooth, the orange efect is ob ide with a diameter range between 0.15 and 0.3 �m The technician must consider the diferences in Diferences in the refractive indices between enam-
served i n transmitted light when the shorter (blue) that form compact hexagonal structures'J; the inter refractive indices and surface reflection between nat el in air and water give rise to completely diferent
wavelengths in the spectrum are absorbed by the stices of these structures contain traces of water ural and ceramic teeth. Both aspects illustrate how efects. When a tooth or restoration is immersed i n
hydroxyapatite crystals, and the longer (orange) molecules, which, when combined with the silicon natural teeth and the ceramic restorations adapt dif water or positioned in t h e oral cavity and covered
wavelengths are reflected by the enamel. The milky dioxide particles, disperse the light that comes into ferently to the oral environment. Natural teeth can with saliva, the refractive index decreases and the
blue efect, which is observed in reflected light, is an contact with the opal. be considered translucent owing to the refractive transparency and light reflection also change. In the
effect of the propagation of a luminous blue spec In natural teeth, only 5°/o of the enamel's overall indices of the various structures (eg, enamel, dentin, oral cavity, the relative refraction indices of d i ferent
trum because hydroxyapatite crystals are much small structure consists of organic substances such as and pulp) through which light waves pass. Thus, the enamel materials and diferences in reflected light
er than the wavelength of visible light. proteins, carbohydrates, and water; there is a dom ceramic crown also must be translucent, and its mean that interproximal areas appear darker with
Opalescence in natural teeth is based on the inant presence of inorganic components such as components must behave like the prisms of natural ceramic restorations and brighter with natural teeth.
same color principles that apply to an opal: The pre calcium, phosphorus, magnesium, and fluorine. The tooth enamel so that as much incidental light will be The technician must be aware of these d iferences
cious stone and dental enamel have the same chro most abundant mineral is hydroxyapatite, and when refracted from the crown as possible. The more light before layering ceramic; otherwise, even a restora
matic hues in diferent light conditions. The irides these crystals join together they produce prisms of a restoration transmits, the more transparent it will tion using opalescent ceramic material and a custom
cence of a n opal occurs because the pseudomor various sizes that range from 4 �m at the dentine appear; likewise, the less light a restoration trans stratification technique that is as similar as possible
phosis that lies under the lamellar structures of cal enamel junction to 8 �m close to the tooth's surface. mits, the more opaque it will appear. to natural teeth will be compromised once it has been
cite produces an optical interference. The opal's color These prisms also range in shape from needle-like seated inside the oral cavity (Figs 12-12 to 12-15). .
efects change in different angles of light. An opal to ribbon-like to hexagonal; however, the shape re-
stone consists of spherical particles of silicon diox- mains elongated. ..
Figs 12-4 1D 12-6 Refraction and color phenomena of light transmission d u ring different hours of the day. These color changes
and effects occur from the luminous refractions of sunlight on air particles of different diameters and densities.
379
71
CHAPTER 1 2
L I G H T I N D I F F E R E N T E N V I R O N M E N TA L C O N D I T I O N S
. passes through a tooth, the orange efect is ob ide with a diameter range between 0.15 and 0.3 �m The technician must consider the diferences in Diferences in the refractive indices between enam-
served i n transmitted light when the shorter (blue) that form compact hexagonal structures'J; the inter refractive indices and surface reflection between nat el in air and water give rise to completely diferent
wavelengths in the spectrum are absorbed by the stices of these structures contain traces of water ural and ceramic teeth. Both aspects illustrate how efects. When a tooth or restoration is immersed i n
hydroxyapatite crystals, and the longer (orange) molecules, which, when combined with the silicon natural teeth and the ceramic restorations adapt dif water or positioned in t h e oral cavity and covered
wavelengths are reflected by the enamel. The milky dioxide particles, disperse the light that comes into ferently to the oral environment. Natural teeth can with saliva, the refractive index decreases and the
blue efect, which is observed in reflected light, is an contact with the opal. be considered translucent owing to the refractive transparency and light reflection also change. In the
effect of the propagation of a luminous blue spec In natural teeth, only 5°/o of the enamel's overall indices of the various structures (eg, enamel, dentin, oral cavity, the relative refraction indices of d i ferent
trum because hydroxyapatite crystals are much small structure consists of organic substances such as and pulp) through which light waves pass. Thus, the enamel materials and diferences in reflected light
er than the wavelength of visible light. proteins, carbohydrates, and water; there is a dom ceramic crown also must be translucent, and its mean that interproximal areas appear darker with
Opalescence in natural teeth is based on the inant presence of inorganic components such as components must behave like the prisms of natural ceramic restorations and brighter with natural teeth.
same color principles that apply to an opal: The pre calcium, phosphorus, magnesium, and fluorine. The tooth enamel so that as much incidental light will be The technician must be aware of these d iferences
cious stone and dental enamel have the same chro most abundant mineral is hydroxyapatite, and when refracted from the crown as possible. The more light before layering ceramic; otherwise, even a restora
matic hues in diferent light conditions. The irides these crystals join together they produce prisms of a restoration transmits, the more transparent it will tion using opalescent ceramic material and a custom
cence of a n opal occurs because the pseudomor various sizes that range from 4 �m at the dentine appear; likewise, the less light a restoration trans stratification technique that is as similar as possible
phosis that lies under the lamellar structures of cal enamel junction to 8 �m close to the tooth's surface. mits, the more opaque it will appear. to natural teeth will be compromised once it has been
cite produces an optical interference. The opal's color These prisms also range in shape from needle-like seated inside the oral cavity (Figs 12-12 to 12-15). .
efects change in different angles of light. An opal to ribbon-like to hexagonal; however, the shape re-
stone consists of spherical particles of silicon diox- mains elongated. ..
Figs 12-4 1D 12-6 Refraction and color phenomena of light transmission d u ring different hours of the day. These color changes
and effects occur from the luminous refractions of sunlight on air particles of different diameters and densities.
379
71
CHAPHR 2
Figs 12-7 and 12-8 The surface quality. position. and size of the teeth influence light distribution. hue. color saturation. and
brilliance.
Fig 12-g Example of opalescence in nature.
Fig 12-10 Blue and orange opalescent effects in ceramic restorations.
Fig 12-11 Transmission of orange light through a natural tooth.
Fig 12-12 Environmental and light conditions as the sun sets can be compared to the situation of light transmitted through teeth.
Fig 12-13 Opalescence of two all-ceramic restorations with transparent cores that allow light transmission through the entire crown.
Figs 12-14 and 12-15 Opalescence of two metal-ceramic restorations. before and afler cementation and integration in the oral
cavity. The metal cores block light transmission.
381
CHAPHR 2
Figs 12-7 and 12-8 The surface quality. position. and size of the teeth influence light distribution. hue. color saturation. and
brilliance.
Fig 12-g Example of opalescence in nature.
Fig 12-10 Blue and orange opalescent effects in ceramic restorations.
Fig 12-11 Transmission of orange light through a natural tooth.
Fig 12-12 Environmental and light conditions as the sun sets can be compared to the situation of light transmitted through teeth.
Fig 12-13 Opalescence of two all-ceramic restorations with transparent cores that allow light transmission through the entire crown.
Figs 12-14 and 12-15 Opalescence of two metal-ceramic restorations. before and afler cementation and integration in the oral
cavity. The metal cores block light transmission.
381
C H APTER 1 2
• Fluorescence areas of natural tooth are equally fluorescent (Figs

12-19 and 12-20). The variation of the fluorescent
Fluorescence is the absorption of electromagnetic effects must be planned during the color-matching
energy of one wavelength with the simultaneous phase by determ i ning how the layers wilt be over
emission of radiation of a longer wavelength, there lapped, so they can later be arranged to achieve the
by rendering it visible to the human eye.'l The fluo desired result (Figs 12-21 and 12-22). The dental tech
rescence of natural teeth is visible as a white-blue nician must be familiar with the fluorescence level of
hue when it is exposed to ultraviolet light with a the different materials included in the laboratory
wavelength of less than 400 nm. ceramic kit by examining them with a Woods lamp
Fluorescent l igh t has a shorter wavelength and and classifying the colors as fluorescent or nonfluo
greater energy than wavelengths of the visible spec· rescent. To accomplish the esthetic aims of the res
trum; in fact, if the light faits on a fluorescent body, toration, the technician wilt need to have available
the atoms and molecules in an excited state wilt both ceramic that transmits light and ceramic that
emit radiation with less energy. Fluorescence in nat· limits its refraction (Fig 12-23).
ural teeth is associated with the presence of the
organic component, which explains why it occurs in
the dentin layer and not in the opalescent enamel CERA M I C STRATI F I CATI O N
layer, which contains more inorganic components. TECH N I QU ES
Since natural teeth have a distinct fluorescence,
the ceramic dental material should similarly fluo
One-firing tech nique
resce (Figs 12-16 and 12-17). Greater fluorescence is
visible in the lighter shades; furthermore, too much Shoulder ceramic
fluorescence over the entire restoration produces an For metal-ceramic fixed partial dentures and crowns,
artificial efect. The authors use high-fluorescence the metal collar is reduced at the cervical margin to
shoulder porcelain to illuminate the cervical margin make room for the shoulder porcelain and create a
(Fig 12-18). During the ceramic layering, the technician so-called collarless restoration (Fig 12-24). Only min
must achieve a variable fluorescence, since not all imal reduction can be performed on the metal collar .
Fig 12-16 Natural tooth shows a sognificant fluorescence. especially if compared with the presence of nonfluorescing pigmen
tation. Fig 12-17 Ceramic restoration that simulates a satisfactory overall fluorescence. although it is slightly limited by non
fluorescong surface pigments. Fig 12-18 Intense fluorescence in the ceramic of the cervical margin is required to effectively
illuminate the gingiva. Fig 12-19 fluorescence of two metal-ceramic restorations suitably calibrated over the entire restoration.
There is not a standard level of fluorescence for each layer, the dental technician needs to know how the different levels of
fluorescence of the ceramic material can be used to evenly distribute light and ensure a more natural effect for the restora
tive treatment. Fig 12-20 Definitive restoration in the oral cavity. Optimum integration is possible despite significant metal
cores because of the expert management of the fluorescence of the cerami c layers. Fig 12-21 Degrees of fluorescence for
dentin and enamel materials. Fig 12-22 Degrees of fluorescence for modifier materials. Materials with less fluorescence have
more chroma. Fig 12-23 Internal and external colorings with different degrees of fluorescence (le) or nonfluorescence /right).
2
C H APTER 1 2
• Fluorescence areas of natural tooth are equally fluorescent (Figs

12-19 and 12-20). The variation of the fluorescent
Fluorescence is the absorption of electromagnetic effects must be planned during the color-matching
energy of one wavelength with the simultaneous phase by determ i ning how the layers wilt be over
emission of radiation of a longer wavelength, there lapped, so they can later be arranged to achieve the
by rendering it visible to the human eye.'l The fluo desired result (Figs 12-21 and 12-22). The dental tech
rescence of natural teeth is visible as a white-blue nician must be familiar with the fluorescence level of
hue when it is exposed to ultraviolet light with a the different materials included in the laboratory
wavelength of less than 400 nm. ceramic kit by examining them with a Woods lamp
Fluorescent l igh t has a shorter wavelength and and classifying the colors as fluorescent or nonfluo
greater energy than wavelengths of the visible spec· rescent. To accomplish the esthetic aims of the res
trum; in fact, if the light faits on a fluorescent body, toration, the technician wilt need to have available
the atoms and molecules in an excited state wilt both ceramic that transmits light and ceramic that
emit radiation with less energy. Fluorescence in nat· limits its refraction (Fig 12-23).
ural teeth is associated with the presence of the
organic component, which explains why it occurs in
the dentin layer and not in the opalescent enamel CERA M I C STRATI F I CATI O N
layer, which contains more inorganic components. TECH N I QU ES
Since natural teeth have a distinct fluorescence,
the ceramic dental material should similarly fluo
One-firing tech nique
resce (Figs 12-16 and 12-17). Greater fluorescence is
visible in the lighter shades; furthermore, too much Shoulder ceramic
fluorescence over the entire restoration produces an For metal-ceramic fixed partial dentures and crowns,
artificial efect. The authors use high-fluorescence the metal collar is reduced at the cervical margin to
shoulder porcelain to illuminate the cervical margin make room for the shoulder porcelain and create a
(Fig 12-18). During the ceramic layering, the technician so-called collarless restoration (Fig 12-24). Only min
must achieve a variable fluorescence, since not all imal reduction can be performed on the metal collar .
Fig 12-16 Natural tooth shows a sognificant fluorescence. especially if compared with the presence of nonfluorescing pigmen
tation. Fig 12-17 Ceramic restoration that simulates a satisfactory overall fluorescence. although it is slightly limited by non
fluorescong surface pigments. Fig 12-18 Intense fluorescence in the ceramic of the cervical margin is required to effectively
illuminate the gingiva. Fig 12-19 fluorescence of two metal-ceramic restorations suitably calibrated over the entire restoration.
There is not a standard level of fluorescence for each layer, the dental technician needs to know how the different levels of
fluorescence of the ceramic material can be used to evenly distribute light and ensure a more natural effect for the restora
tive treatment. Fig 12-20 Definitive restoration in the oral cavity. Optimum integration is possible despite significant metal
cores because of the expert management of the fluorescence of the cerami c layers. Fig 12-21 Degrees of fluorescence for
dentin and enamel materials. Fig 12-22 Degrees of fluorescence for modifier materials. Materials with less fluorescence have
more chroma. Fig 12-23 Internal and external colorings with different degrees of fluorescence (le) or nonfluorescence /right).
2
CHAPTER 1 2
� of a metal-ceramic fixed partial denture, since more traditional way, the crown is removed for a second
marginal support for the ceramic veneer is required firing in accordance with the manufacturer's instruc
to efectively dissipate the occlusal loads. In the case tions for the ceramic system used. Another method
of single crowns or veneers. the metal collar can be used during the corrective phase of the shoulder
reduced much more signiicantly on the buccal aspect. layer is to add a mixture of wax and ceramic mater
For metal-ceramic restorations. the authors prefer to ial, which is later externally reinforced with a tradi
apply the ceramic directly on a refractory die, start tional ceramic shoulder layer, using powder and liq
ing with the shoulder porcelain at the cervical mar uid. When the wax is subjected to heat during the
gin. When porcelain laminate veneers are prepared, preheating phase. it tends to melt and is absorbed
the authors fire the shoulder and transparent ceram by the external ceramic material, which prevents the
ic or enamel and dentin ceramic to stabilize it for the distortion and maintains the stability of the ceramic
subsequent firings and prevent detachment from the material after firing.•B.•9
refractoy die (Figs 12-25 and 12-26).
Use of a highly fluorescent shoulder porcelain Opaque dentin
enables light to illuminate the root and the gingi Ceramic layers are arranged to obtain the desired
va••-•' (Fig 12-27). I f the metal coping adheres too efect and, depending on the type of core, to achieve
closely to the plaster die, serious dificulties could transparency, fluorescence. and color. Opaque dentin
arise when removing the crown. Therefore, the entire should be used for all restorations, including those Fig 1 2-24 Example of the metal substructure of a metal-ceramic restoration where the marginal shoulder is intended to be built
up with ceramic material Fig 12-15 lhe .f irst bake of the ceramic material prevents detachment during subsequent firing. The
;
ceramiC IS f1red at a gso C. whiCh IS higher than normal temperatures used i n laboratory procedures. Fig 12-26 Brilliance of
plaster die must be layered with isolating material with a metal margin; the opaque dentin covers thin
before ceramic is added to the shoulder. The shoul margins and has a lower melting temperature, which the ceramic edges after firing the marginal shoulder porcelain. Fig 12-27 Satisfactory quality of the shoulder porcelain. which
shows a higher degree of fluorescence than other parts of the metal-ceramic restoration.
der porcelain solidifies as it dries and can be sepa i mproves firing and closure. Areas at the cervical
rated from the isolated die. However, if drying times margin that are not built up with shoulder porcelain
are excessive, the ceramic will absorb the isolating should be layered with a dentin and enamel collar
material, which weakens the structure and can lead over the opaque dentin to simulate depth. When the
� Labial stratification the process and layered solely on the exterior sur
to its failure when the crown is removed from the final layer is exposed to a moist environment, its
On the incisal wall, translucent enamel and trans face. The desired result is achieved by layering
die. The authors generally recommend removal of appearance is more translucent, which reduces the
lucent opalescent materials are introduced in the ceramic and colors in between the dentin and the
the shoulder porcelain when the ceramic particles plaster-like appearance after firing.
mamelon site where the dentin material has been enamel layers, while keeping the entire restoration
are white in color. A thin layer of opaque dentin covers the entire
trimmed. Translucent porcelain with highly fluores moist. The incisal wall deseves more attention dur
In the majority of cases, the ceramic layer over surface of the crown, while an opaque dentin with
cent properties and iridescent characteristics can ing stratiication since this area can be customized
the opaque layer shrinks after the shoulder porce greater brilliance and high fluorescence is posi
improve the brilliance in this area (Figs 12-31 and by applying a wide variety of porcelains, and the
lain is fired for the first time. This layer is built u p tioned between the middle and incisal thirds of the
12-32). The chromatic monotony in the cervical third incisal edge can be completed with vertical layers of
again b y applying a new layer of colored shoulder tooth. The tooth's anatomic shape is built up with
can be interrupted by adding a layer of high-value enamel and translucent material with diferent de
porcelain that masks the transition between the the dentin material on top of the first layer of
porcelain (Fig 12-33). Modiiers and colors with dif grees of opacity.
coping and the opaque material. The restoration is opaque dentin, and then trimmed to create space
ferent degrees of fluorescence are layered on the There are no set rules or schemes for arranging
adapted on the die by adding this corrective ceram for the color, color-modifier, enamel, and translucent
incisal wall to increase luminosity'9 and create con ceramic layers, especially since no two teeth are alike
ic layer after the first firing and, proceeding in the materials (Figs 12-28 to 12-30). ,.
trast (Fig 12-34). and so much depends on the type of restoration that
Customized ceramic efects are developed during is chosen. For example, translucent blue can be used
stratification and should not be left to the end of in the buccoproximal area to imitate the refraction .
15
CHAPTER 1 2
� of a metal-ceramic fixed partial denture, since more traditional way, the crown is removed for a second
marginal support for the ceramic veneer is required firing in accordance with the manufacturer's instruc
to efectively dissipate the occlusal loads. In the case tions for the ceramic system used. Another method
of single crowns or veneers. the metal collar can be used during the corrective phase of the shoulder
reduced much more signiicantly on the buccal aspect. layer is to add a mixture of wax and ceramic mater
For metal-ceramic restorations. the authors prefer to ial, which is later externally reinforced with a tradi
apply the ceramic directly on a refractory die, start tional ceramic shoulder layer, using powder and liq
ing with the shoulder porcelain at the cervical mar uid. When the wax is subjected to heat during the
gin. When porcelain laminate veneers are prepared, preheating phase. it tends to melt and is absorbed
the authors fire the shoulder and transparent ceram by the external ceramic material, which prevents the
ic or enamel and dentin ceramic to stabilize it for the distortion and maintains the stability of the ceramic
subsequent firings and prevent detachment from the material after firing.•B.•9
refractoy die (Figs 12-25 and 12-26).
Use of a highly fluorescent shoulder porcelain Opaque dentin
enables light to illuminate the root and the gingi Ceramic layers are arranged to obtain the desired
va••-•' (Fig 12-27). I f the metal coping adheres too efect and, depending on the type of core, to achieve
closely to the plaster die, serious dificulties could transparency, fluorescence. and color. Opaque dentin
arise when removing the crown. Therefore, the entire should be used for all restorations, including those Fig 1 2-24 Example of the metal substructure of a metal-ceramic restoration where the marginal shoulder is intended to be built
up with ceramic material Fig 12-15 lhe .f irst bake of the ceramic material prevents detachment during subsequent firing. The
;
ceramiC IS f1red at a gso C. whiCh IS higher than normal temperatures used i n laboratory procedures. Fig 12-26 Brilliance of
plaster die must be layered with isolating material with a metal margin; the opaque dentin covers thin
before ceramic is added to the shoulder. The shoul margins and has a lower melting temperature, which the ceramic edges after firing the marginal shoulder porcelain. Fig 12-27 Satisfactory quality of the shoulder porcelain. which
shows a higher degree of fluorescence than other parts of the metal-ceramic restoration.
der porcelain solidifies as it dries and can be sepa i mproves firing and closure. Areas at the cervical
rated from the isolated die. However, if drying times margin that are not built up with shoulder porcelain
are excessive, the ceramic will absorb the isolating should be layered with a dentin and enamel collar
material, which weakens the structure and can lead over the opaque dentin to simulate depth. When the
� Labial stratification the process and layered solely on the exterior sur
to its failure when the crown is removed from the final layer is exposed to a moist environment, its
On the incisal wall, translucent enamel and trans face. The desired result is achieved by layering
die. The authors generally recommend removal of appearance is more translucent, which reduces the
lucent opalescent materials are introduced in the ceramic and colors in between the dentin and the
the shoulder porcelain when the ceramic particles plaster-like appearance after firing.
mamelon site where the dentin material has been enamel layers, while keeping the entire restoration
are white in color. A thin layer of opaque dentin covers the entire
trimmed. Translucent porcelain with highly fluores moist. The incisal wall deseves more attention dur
In the majority of cases, the ceramic layer over surface of the crown, while an opaque dentin with
cent properties and iridescent characteristics can ing stratiication since this area can be customized
the opaque layer shrinks after the shoulder porce greater brilliance and high fluorescence is posi
improve the brilliance in this area (Figs 12-31 and by applying a wide variety of porcelains, and the
lain is fired for the first time. This layer is built u p tioned between the middle and incisal thirds of the
12-32). The chromatic monotony in the cervical third incisal edge can be completed with vertical layers of
again b y applying a new layer of colored shoulder tooth. The tooth's anatomic shape is built up with
can be interrupted by adding a layer of high-value enamel and translucent material with diferent de
porcelain that masks the transition between the the dentin material on top of the first layer of
porcelain (Fig 12-33). Modiiers and colors with dif grees of opacity.
coping and the opaque material. The restoration is opaque dentin, and then trimmed to create space
ferent degrees of fluorescence are layered on the There are no set rules or schemes for arranging
adapted on the die by adding this corrective ceram for the color, color-modifier, enamel, and translucent
incisal wall to increase luminosity'9 and create con ceramic layers, especially since no two teeth are alike
ic layer after the first firing and, proceeding in the materials (Figs 12-28 to 12-30). ,.
trast (Fig 12-34). and so much depends on the type of restoration that
Customized ceramic efects are developed during is chosen. For example, translucent blue can be used
stratification and should not be left to the end of in the buccoproximal area to imitate the refraction .
15
CHAP
_.---�
- -��=��
-
• efect typical of natural teeth. The technician can pro the incisal wall enhances the overall efect and con·
ceed with other stratification combinations. such as trast, which lends vitality to the restoration. Natural
a vitreous enamel layer, an enamel layer, an opales· enamel crazing can be simulated using vertical lines
cent cevical layer, or an opalescent translucent layer. of color positioned vertically on the enamel of the
Ceramic kits contain a broad range of porcelains, incisal wall; this is how a natural appearance is
whose derivatives can be mixed together to obtain achieved.
original efects that make the restoration more nat· The shape of the middle third is built up with
ural in appearance. translucent opalescent materials of different shades
Fig 12-28 Opaque dentin layered over the metal copings that have been treated with opaque material. Fig 12-29 Dentin-type ceramic is layered
The technician must avoid a final color that is too and gradations; a translucent porcelain, which can over the opaque dentin. Fig 12-30 Buildup of the dentin layer is monitored with a silicone index of the wax pattern. I n this way the operator
uniform (eg, gray teeth due to the exclusive use of be modified with another translucent porcelain that will be able to layer the dentin material to support the different enamel and translucent layers. Fig 12-31 Enamel-type material built up on the
incisal edges. During the construction of the incisal edge. it is important that the ceramic layers a � d colors integr.te effectively. ig 12-32
porcelains in gradations of gray) by vaying the over· has iridescent and nuorescent characteristics, is lay· Completion of the incisal edge with alternating layers of translucent and enamel matenals. Fig 12-33 H1gh-value ceram1c IS layered 1n the cer
vical third to increase brilliance. Fig 12-4 layers of modifiers and colors direclly on the incisal edge. The environment must be kept moist
all color using diferent shades (Fig 12-35). Futher ered over the ceramic collar in the cervical third
during the layering to ensure a better overall result. Fig 12- 35 Diversified vertical layers. alternating ena mels and translucent materials with
_
different shades and gradation. Fig 12-36 Translucent materials _
1n the middle third of the crown help to Simulate depth. Fig 12-37 The cerv1cal
more, the underlying color between the dentin and (Figs 12 ·36 and 12·37). ..
third is completed with a translucent layer directly over the restoration collar. ThiS layer IS more chromatic than the other translucent mate
rials.
87
CHAP
_.---�
- -��=��
-
• efect typical of natural teeth. The technician can pro the incisal wall enhances the overall efect and con·
ceed with other stratification combinations. such as trast, which lends vitality to the restoration. Natural
a vitreous enamel layer, an enamel layer, an opales· enamel crazing can be simulated using vertical lines
cent cevical layer, or an opalescent translucent layer. of color positioned vertically on the enamel of the
Ceramic kits contain a broad range of porcelains, incisal wall; this is how a natural appearance is
whose derivatives can be mixed together to obtain achieved.
original efects that make the restoration more nat· The shape of the middle third is built up with
ural in appearance. translucent opalescent materials of different shades
Fig 12-28 Opaque dentin layered over the metal copings that have been treated with opaque material. Fig 12-29 Dentin-type ceramic is layered
The technician must avoid a final color that is too and gradations; a translucent porcelain, which can over the opaque dentin. Fig 12-30 Buildup of the dentin layer is monitored with a silicone index of the wax pattern. I n this way the operator
uniform (eg, gray teeth due to the exclusive use of be modified with another translucent porcelain that will be able to layer the dentin material to support the different enamel and translucent layers. Fig 12-31 Enamel-type material built up on the
incisal edges. During the construction of the incisal edge. it is important that the ceramic layers a � d colors integr.te effectively. ig 12-32
porcelains in gradations of gray) by vaying the over· has iridescent and nuorescent characteristics, is lay· Completion of the incisal edge with alternating layers of translucent and enamel matenals. Fig 12-33 H1gh-value ceram1c IS layered 1n the cer
vical third to increase brilliance. Fig 12-4 layers of modifiers and colors direclly on the incisal edge. The environment must be kept moist
all color using diferent shades (Fig 12-35). Futher ered over the ceramic collar in the cervical third
during the layering to ensure a better overall result. Fig 12- 35 Diversified vertical layers. alternating ena mels and translucent materials with
_
different shades and gradation. Fig 12-36 Translucent materials _
1n the middle third of the crown help to Simulate depth. Fig 12-37 The cerv1cal
more, the underlying color between the dentin and (Figs 12 ·36 and 12·37). ..
third is completed with a translucent layer directly over the restoration collar. ThiS layer IS more chromatic than the other translucent mate
rials.
87
CHAPTER 1 2
• Palatal stratification bur are first marked in graphite to better arrange the
After the labial surface is completed, the next step ridges that give texture to the buccal surface of the
is the stratification of the palatal surface. A mixture tooth (Figs 12-44 and 12-45). Finally, the interproxi·
of opaque dentin and modifier is layered over the mal spaces must have a wider shape toward the
palatal surface, while a more liquid solution is used palatal area in order to close the black spaces.
at the transition between the crown and tooth to In the technique described so far, all the neces
make the entire surface uniform (Fig 12·38). The in· sary ceramic layers have been introduced in a single
cisal crests and cusps are built up using dentin and phase.
enamels and layered with translucent materials (Fig The second, or corrective, stage can be carried
12-39). To mimic natural colors on the palatal sur· out by adding only small quantities of ceramic to
face caused by the prolonged exposure to acidic optimize the shape. The final finishing, completed
saliva, the technician uses a more chromatic opaque after the second firing, refines the surface of the
dentin (eg, a shade from Vita Lumin Vacuum), which deinitive restoration to facilitate an esthetic integra
can reflect light when applied at a special angle. tion with neighboring teeth. The technician should
The stratification continues with dentin and cervi· have contact with the patient in this phase to apply
cal enamel layers (Figs 12-40 to 12-43). When space lacquers or gold or silver powders to the natural
is limited, a transparent cevical and dentin mixture teeth for observing the natural surface texture. The
can be layered over opaque dentin to simulate work proceeds with the closure of the shoulder
depth. The incisal edge is trimmed using a sharp ceramic on the tooth preparations or the master cast
tool, and an enamel-dentin mixture and a 10% stain using a wax-ceramic mixture. The surface characteri
or ceramic modiier are applied to simulate abrasions zation can then be executed at the same time using
and highlight the presence of seconday dentin. The colors; these procedures are completed as the tech·
ceramic material can be fired according to the man· nician applies the ceramic, then bakes the restora
uacturer's instructions, but every dental technician tion in the furnace (Fig 12-46). Color characterizations
adapts techniques to achieve optimal results. are applied to the surface both in fine grit, which
makes the surface more uniform, and coarse grit,
Finishing and corrective firing which adds a degree of thickness. The rubber points
The ceramic restorations are finished on the sec are used only to finish the cervical site under mag
tioned cast ater the first firing, using rotating burs. nification after the firing has been completed, while
The technician must be careful to avoid compromis the polishing phase of the remaining part of the sur
ing the gingival anatomy of the cast. Areas on the face is executed manually using the large laboratoy
ceramic surface that need to be finished with the cleaning machine dedicated to this purpose. ..
Fig 12-38 Modified opaque dentin is layered over the pa_latal surface. A more .liquid material is introduced at the incisal third
to make the tooth more uniform. Fig 12-39 Dentin malenals layered over the ' 1rsl layer of opaque denton. Fi� 12�4D Applocal1on
of enamel and translucent materials. Figs 12-41 and 12-42 Tnangular area on 1nterprox1mal surface for apphcal1on of reflect
ing opaque dentin. fig 12-43 Dentin material layered over the opaque dentin. The last layer of enamel on the ceramic collar
completes the stratification procedure.
CHAPTER 1 2
• Palatal stratification bur are first marked in graphite to better arrange the
After the labial surface is completed, the next step ridges that give texture to the buccal surface of the
is the stratification of the palatal surface. A mixture tooth (Figs 12-44 and 12-45). Finally, the interproxi·
of opaque dentin and modifier is layered over the mal spaces must have a wider shape toward the
palatal surface, while a more liquid solution is used palatal area in order to close the black spaces.
at the transition between the crown and tooth to In the technique described so far, all the neces
make the entire surface uniform (Fig 12·38). The in· sary ceramic layers have been introduced in a single
cisal crests and cusps are built up using dentin and phase.
enamels and layered with translucent materials (Fig The second, or corrective, stage can be carried
12-39). To mimic natural colors on the palatal sur· out by adding only small quantities of ceramic to
face caused by the prolonged exposure to acidic optimize the shape. The final finishing, completed
saliva, the technician uses a more chromatic opaque after the second firing, refines the surface of the
dentin (eg, a shade from Vita Lumin Vacuum), which deinitive restoration to facilitate an esthetic integra
can reflect light when applied at a special angle. tion with neighboring teeth. The technician should
The stratification continues with dentin and cervi· have contact with the patient in this phase to apply
cal enamel layers (Figs 12-40 to 12-43). When space lacquers or gold or silver powders to the natural
is limited, a transparent cevical and dentin mixture teeth for observing the natural surface texture. The
can be layered over opaque dentin to simulate work proceeds with the closure of the shoulder
depth. The incisal edge is trimmed using a sharp ceramic on the tooth preparations or the master cast
tool, and an enamel-dentin mixture and a 10% stain using a wax-ceramic mixture. The surface characteri
or ceramic modiier are applied to simulate abrasions zation can then be executed at the same time using
and highlight the presence of seconday dentin. The colors; these procedures are completed as the tech·
ceramic material can be fired according to the man· nician applies the ceramic, then bakes the restora
uacturer's instructions, but every dental technician tion in the furnace (Fig 12-46). Color characterizations
adapts techniques to achieve optimal results. are applied to the surface both in fine grit, which
makes the surface more uniform, and coarse grit,
Finishing and corrective firing which adds a degree of thickness. The rubber points
The ceramic restorations are finished on the sec are used only to finish the cervical site under mag
tioned cast ater the first firing, using rotating burs. nification after the firing has been completed, while
The technician must be careful to avoid compromis the polishing phase of the remaining part of the sur
ing the gingival anatomy of the cast. Areas on the face is executed manually using the large laboratoy
ceramic surface that need to be finished with the cleaning machine dedicated to this purpose. ..
Fig 12-38 Modified opaque dentin is layered over the pa_latal surface. A more .liquid material is introduced at the incisal third
to make the tooth more uniform. Fig 12-39 Dentin malenals layered over the ' 1rsl layer of opaque denton. Fi� 12�4D Applocal1on
of enamel and translucent materials. Figs 12-41 and 12-42 Tnangular area on 1nterprox1mal surface for apphcal1on of reflect
ing opaque dentin. fig 12-43 Dentin material layered over the opaque dentin. The last layer of enamel on the ceramic collar
completes the stratification procedure.
CHAPTER 1 2
. This restoration is therefore completed with a Blocked color tech n i q u e

single-firing stratification, in which all of the chro
matic characteristics, the modifiers, and the colors After t h e restoration is trimmed following t h e first
are correctly layered for the first fi ri ng, while the sec firing, colored ceramic materials that are more or
ond firing represents only a corrective firing of the less fluorescent can be layered in the reduced areas.
morphology. After the firing has been completed, They are fixed using intermediate firing at 850°C
rubber points are used to finish the cervical site under vacuum with a temperature increase of 8o°C
under magnification. The polishing of the remaining per minute, which is followed by rapid cooling (Figs
restoration surface is executed manually using the 12-47 to 12-49). The enamel and translucent layers
laboratory cleaning machine. will be removed only at this point, creating an
However, the technician can adopt different meth· "enamel skin," or an enamel surface that will en
ads of stratification, including the blocked colors20 hance the color-contrast efect (Figs 12-50 to 12-53) . ..
and double sandwich techniques.
1 2- 4 5
Figs 12-44 and 1 2-45 A graphite pencil highlights the arrangement o f the ridges and the macrogeography plan for the labial and palatal sur
faces. Fig 12-46 Completed metal-ceramic restorations after trimming and polishing. Figs 12-47 and 12-48 Ceramic materials after the first fir
ing. The crowns have been partly trimmed with the help of a sectioned silicone index. The overall volume of the crowns is smaller than the
wax pattern. and therefore, new colors can be layered over the entire surface. Fig 12-4g Definitive ceramic restoration on the cast and ready
to be seated in the mouth. During the corrective firing stage. colors and a ceramic were layered. Fig 1 2-SD Clinical situation prior to treat
ment. Figs 12-51 o 12-53 D e finitive restoration 2 weeks after cementation in the oral cavity. The two feldspathic ceramic veneers have inte
grated esthetically despite the excessively apical position of the gingival margin on the two lateral incisors.
91
CHAPTER 1 2
. This restoration is therefore completed with a Blocked color tech n i q u e

single-firing stratification, in which all of the chro
matic characteristics, the modifiers, and the colors After t h e restoration is trimmed following t h e first
are correctly layered for the first fi ri ng, while the sec firing, colored ceramic materials that are more or
ond firing represents only a corrective firing of the less fluorescent can be layered in the reduced areas.
morphology. After the firing has been completed, They are fixed using intermediate firing at 850°C
rubber points are used to finish the cervical site under vacuum with a temperature increase of 8o°C
under magnification. The polishing of the remaining per minute, which is followed by rapid cooling (Figs
restoration surface is executed manually using the 12-47 to 12-49). The enamel and translucent layers
laboratory cleaning machine. will be removed only at this point, creating an
However, the technician can adopt different meth· "enamel skin," or an enamel surface that will en
ads of stratification, including the blocked colors20 hance the color-contrast efect (Figs 12-50 to 12-53) . ..
and double sandwich techniques.
1 2- 4 5
Figs 12-44 and 1 2-45 A graphite pencil highlights the arrangement o f the ridges and the macrogeography plan for the labial and palatal sur
faces. Fig 12-46 Completed metal-ceramic restorations after trimming and polishing. Figs 12-47 and 12-48 Ceramic materials after the first fir
ing. The crowns have been partly trimmed with the help of a sectioned silicone index. The overall volume of the crowns is smaller than the
wax pattern. and therefore, new colors can be layered over the entire surface. Fig 12-4g Definitive ceramic restoration on the cast and ready
to be seated in the mouth. During the corrective firing stage. colors and a ceramic were layered. Fig 1 2-SD Clinical situation prior to treat
ment. Figs 12-51 o 12-53 D e finitive restoration 2 weeks after cementation in the oral cavity. The two feldspathic ceramic veneers have inte
grated esthetically despite the excessively apical position of the gingival margin on the two lateral incisors.
91
CHAPTER 1 2
---,
-----�=�=��
.. Double sandwich tech nique cent materials. An additional layer of modifiers and
colors are then covered by successive layers of
T h e double sandwich technique c a n proceed after enamel and translucent materials to complete the
the first firing and trimming, either following the restoration (Figs 12-55 to 12-58). This type of custom
addition of layers to define the tooth's morphology stratification creates greater contrast and gives the
or to block the colors, and can then continue with restoration the most natural appearance. The tech
the addition of shape-correcting layers. Modifiers and nician focuses on the incisal third to the middle
colors are layered on the incisal wall (Fig 12-54), third of the crown to give greater brilliance to the
which are in turn covered by enamels and translu- stratification (Figs 12-59 to 12-63). .
Fig 12-4 First incisal layer with the modifiers and colors.
Fig 12-55 Second incisal laye r.
Fig 12-56 Application of further modifiers and colors.
Fig 12-57 Stratification completed using a silicone index.
Fig 12-58 Completion of first firing.
m
CHAPTER 1 2
---,
-----�=�=��
.. Double sandwich tech nique cent materials. An additional layer of modifiers and
colors are then covered by successive layers of
T h e double sandwich technique c a n proceed after enamel and translucent materials to complete the
the first firing and trimming, either following the restoration (Figs 12-55 to 12-58). This type of custom
addition of layers to define the tooth's morphology stratification creates greater contrast and gives the
or to block the colors, and can then continue with restoration the most natural appearance. The tech
the addition of shape-correcting layers. Modifiers and nician focuses on the incisal third to the middle
colors are layered on the incisal wall (Fig 12-54), third of the crown to give greater brilliance to the
which are in turn covered by enamels and translu- stratification (Figs 12-59 to 12-63). .
Fig 12-4 First incisal layer with the modifiers and colors.
Fig 12-55 Second incisal laye r.
Fig 12-56 Application of further modifiers and colors.
Fig 12-57 Stratification completed using a silicone index.
Fig 12-58 Completion of first firing.
m
CHAPTER 1 2
Esthetic Consideratio ns for Ceramic Restorations
.. BISQUE TEST AND FI NAL CHECK Su rface fi nishing
Once the restoration has been completed on the Adequate t i m e must be devoted to the final finish
sectioned cast, it is transferred to the unsectioned ing of the restoration surface, which refines the
stone cast so that the accuracy of the contact points anatomy of the teeth. This is implemented using a
and the occlusion can be checked. The position of laboratory handpiece operated at low speed and a
the teeth and the occlusal relationships can be eval series of specially designed burs. Vertical lines can
uated more effectively on a fixed-die cast without be executed with a conical bur (7856.104.023,
the detailed soft tissue information. Komet) (Fig 12-64), and horizontal lines are defined
The crowns or veneers are adapted with the help immediately afterward using a cylindrical bur (Leach
of an articulation chart to eliminate areas of friction & Dillon) (Fig 12-65). The surface is abraded using a
and achieve accurate seating. The technician must short inverted conical bur (805.104.021, Komet) (Fig
work with maximum precision to improve coopera· 12-66), while operation is continued intermittently in
tion between the dental ofice and the laboratory the horizontal direction. A slot-type bur (H246.314.
and to limit the number of corrections made during 009, Komet) is used selectively in both directions in
the ty-ins. certain areas on the labial surface (Fig 12-67). The
Evaluation of the definitive restoration in the entire surface is then inished with a sandpaper
bisque stage should consider its relationship to the cone (Ohki Chemical) (Fig 12-68) and finally with a
soft tissues and its overall color. Glazing liquid is sectioned-wheel rubber point (no. 3 Upofix, Komet)
layered over the surface to highlight the natural (Fig 12-69) to obtain the concavities that give the
effects of the ceramic materials. The veneers and all· restoration surface a natural appearance.
ceramic crowns are removed from the refractory dies The restorations are cleaned with ethyl acetate or
once they are polished, and the color, saturation, rectified petrol and a steam jet, and the glazing liq
value, and translucent appearance of the restoration uid and surface colors are subsequently applied and
can then be judged. At this stage, it is important to fired at 895°C, with temperature increases of 90°C
take a number of photographs in accordance with per minute, to achieve the final luster. Polishing of
the laboratory protocol (see chapter 1) to complete the crowns continues manually with pumice stone
the evaluation of the restorations and determine if using the laboratory cleaning machine and the final
any changes are necessay. surface texture must be established according to the
For metal-ceramic crowns, the evaluation of the operator's sensitivity (Fig 12-70). The ceramic crowns
ceramic material in the bisque stage on the plaster are finally ready to be delivered to the dental ofice
working casts allows consideration of both esthetics for the final try-in and cementation.
and functional movements in the oral cavity. This is The clinician must monitor the stability of the
Fig 12-59 Blocking colors on the surf� ces of the restoratio�s A number of ar as have been reduced mechanically to improve the effects after
_ : �
the corrective f1r1ng. Fig 12-60 Tnmm�ng after th� s: con � flnng. The outlines 1n black graphite help the dentat technician to better u n derstand crucial for identiying necessary adjustments. The restorations over time with periodic exams since a
the shape of the restorat1o�s. Fig 12-61 1nltlal ciln �eal Situation of a young patient in need of complete redefinition of the maxillary in cisors. clinical case should never be considered concluded
Numerous Class 3 restorative treatments of the nght _ evaluation must be completed and any necessay cor
antenor segment and the two metal-ceramic restorations have inconsistent color and
shape. F1gs 1 2-62 and 12-63 Definitive restorations with a Significant esthetic improvement in terms of shape and color. The dentition now rections must be made before the clinician can ce (Figs 12-71 to 12-76). �
appears much younger and more allract1ve
ment the restorations and perform the final check.
lf4 5
CHAPTER 1 2
Esthetic Consideratio ns for Ceramic Restorations
.. BISQUE TEST AND FI NAL CHECK Su rface fi nishing
Once the restoration has been completed on the Adequate t i m e must be devoted to the final finish
sectioned cast, it is transferred to the unsectioned ing of the restoration surface, which refines the
stone cast so that the accuracy of the contact points anatomy of the teeth. This is implemented using a
and the occlusion can be checked. The position of laboratory handpiece operated at low speed and a
the teeth and the occlusal relationships can be eval series of specially designed burs. Vertical lines can
uated more effectively on a fixed-die cast without be executed with a conical bur (7856.104.023,
the detailed soft tissue information. Komet) (Fig 12-64), and horizontal lines are defined
The crowns or veneers are adapted with the help immediately afterward using a cylindrical bur (Leach
of an articulation chart to eliminate areas of friction & Dillon) (Fig 12-65). The surface is abraded using a
and achieve accurate seating. The technician must short inverted conical bur (805.104.021, Komet) (Fig
work with maximum precision to improve coopera· 12-66), while operation is continued intermittently in
tion between the dental ofice and the laboratory the horizontal direction. A slot-type bur (H246.314.
and to limit the number of corrections made during 009, Komet) is used selectively in both directions in
the ty-ins. certain areas on the labial surface (Fig 12-67). The
Evaluation of the definitive restoration in the entire surface is then inished with a sandpaper
bisque stage should consider its relationship to the cone (Ohki Chemical) (Fig 12-68) and finally with a
soft tissues and its overall color. Glazing liquid is sectioned-wheel rubber point (no. 3 Upofix, Komet)
layered over the surface to highlight the natural (Fig 12-69) to obtain the concavities that give the
effects of the ceramic materials. The veneers and all· restoration surface a natural appearance.
ceramic crowns are removed from the refractory dies The restorations are cleaned with ethyl acetate or
once they are polished, and the color, saturation, rectified petrol and a steam jet, and the glazing liq
value, and translucent appearance of the restoration uid and surface colors are subsequently applied and
can then be judged. At this stage, it is important to fired at 895°C, with temperature increases of 90°C
take a number of photographs in accordance with per minute, to achieve the final luster. Polishing of
the laboratory protocol (see chapter 1) to complete the crowns continues manually with pumice stone
the evaluation of the restorations and determine if using the laboratory cleaning machine and the final
any changes are necessay. surface texture must be established according to the
For metal-ceramic crowns, the evaluation of the operator's sensitivity (Fig 12-70). The ceramic crowns
ceramic material in the bisque stage on the plaster are finally ready to be delivered to the dental ofice
working casts allows consideration of both esthetics for the final try-in and cementation.
and functional movements in the oral cavity. This is The clinician must monitor the stability of the
Fig 12-59 Blocking colors on the surf� ces of the restoratio�s A number of ar as have been reduced mechanically to improve the effects after
_ : �
the corrective f1r1ng. Fig 12-60 Tnmm�ng after th� s: con � flnng. The outlines 1n black graphite help the dentat technician to better u n derstand crucial for identiying necessary adjustments. The restorations over time with periodic exams since a
the shape of the restorat1o�s. Fig 12-61 1nltlal ciln �eal Situation of a young patient in need of complete redefinition of the maxillary in cisors. clinical case should never be considered concluded
Numerous Class 3 restorative treatments of the nght _ evaluation must be completed and any necessay cor
antenor segment and the two metal-ceramic restorations have inconsistent color and
shape. F1gs 1 2-62 and 12-63 Definitive restorations with a Significant esthetic improvement in terms of shape and color. The dentition now rections must be made before the clinician can ce (Figs 12-71 to 12-76). �
appears much younger and more allract1ve
ment the restorations and perform the final check.
lf4 5
CHAPTER 1 2
�\
I i
Fig 12-71 Clinical situation of a patient who required restoration of the four maxillary anterior incisors and who requested the redefinition of
Fig 12-4 Vertical lines implemented with a tapered diamond bur on the surface of the cerami c material. Fig 1 2-65 Horizontal lines implement the dental expression with improved esthetics. Fig 12-72 The clinical case showing preparation for three ceramic feldspathic veneers on the
� d w1th a Slntered bur to create the lum1nou � surface contrasts after the vertical lines have been traced. Fig 12-66 A short inverted conical bur right lateral incisor and the two maxillary central incisors. and one metal-ceramic crown on an implant in the left lateral incisor site. Figs
IS u � ed to create diScontinuous honzontal lines. Discontinuity on the tooth's labial surface contributes to the final effect and a more natural 12-73 and 12-74 Definitive restoration 2 weeks postcementation. Adhesive-type cementation was used on the translucent all-ceramic restora
looking restoration. Fig 12-67 A flame-shaped bur creates thinner and more hollow vertical and horizontal grooves. Fig 12-68 A sandpaper cone tions. and a provisional cementation with special resin cement for implants was used on the metal-ceramic crown on the implant. Figs 12-75 and
IS fitted on a stra1ght handpiece and applied over the surface of the restoration to soften the lines created by the burs. fig 12-6g A sectioned 12-76 Patient's smile before and after treatment. showing marked esthetic improvement.
wheel r � bber po1nt " used to create both smooth and rough surfaces. Fig 12-7D Surface texture of the ceramic restoration. which will be fin
IShed With the laboratory cleaning machine.
fl
CHAPTER 1 2
�\
I i
Fig 12-71 Clinical situation of a patient who required restoration of the four maxillary anterior incisors and who requested the redefinition of
Fig 12-4 Vertical lines implemented with a tapered diamond bur on the surface of the cerami c material. Fig 1 2-65 Horizontal lines implement the dental expression with improved esthetics. Fig 12-72 The clinical case showing preparation for three ceramic feldspathic veneers on the
� d w1th a Slntered bur to create the lum1nou � surface contrasts after the vertical lines have been traced. Fig 12-66 A short inverted conical bur right lateral incisor and the two maxillary central incisors. and one metal-ceramic crown on an implant in the left lateral incisor site. Figs
IS u � ed to create diScontinuous honzontal lines. Discontinuity on the tooth's labial surface contributes to the final effect and a more natural 12-73 and 12-74 Definitive restoration 2 weeks postcementation. Adhesive-type cementation was used on the translucent all-ceramic restora
looking restoration. Fig 12-67 A flame-shaped bur creates thinner and more hollow vertical and horizontal grooves. Fig 12-68 A sandpaper cone tions. and a provisional cementation with special resin cement for implants was used on the metal-ceramic crown on the implant. Figs 12-75 and
IS fitted on a stra1ght handpiece and applied over the surface of the restoration to soften the lines created by the burs. fig 12-6g A sectioned 12-76 Patient's smile before and after treatment. showing marked esthetic improvement.
wheel r � bber po1nt " used to create both smooth and rough surfaces. Fig 12-7D Surface texture of the ceramic restoration. which will be fin
IShed With the laboratory cleaning machine.
fl
C H APTER 1 2
.. C O N C L U S I O N S The clinician needs to be familiar with the tech

nical process to help the dental technician fabricate
Prosthetic restoration i s a complex process that re an esthetic and functional restoration (Figs 12-77 to
q uires the use of wax, resin, and ceramic materials. 12-81). The sequence of status photographs (initial
The proposed restoration in the initial treatment clinical situation, provisional restoration in situ, cer
phase must be accepted by the patient and realized amic bisque test, and cemented ceramic material) is
as accurately as possible by the technician to avoid essential to both the laboratory work and the clinical
an unsuccessful esthetic rehabilitation. Successive re evaluation of the restoration (Figs 12-82 to 12-88).
storative stages focus on implementing a provision The ability to interpret the patient's requests
al restoration using acrylic resin, which allows the remains the most important and undoubtedly the
initial wax-based diagnostic plan to be evaluated in most difficult aspect of the entire treatment; the
vivo. The provisional restoration is followed by the success of a restoration depends on the prosthetic
development of the restoration in ceramic materiaL team's ability to realize the patient's requests while
The material that is used must provide long-term maintaining biologic, esthetic, and functional para
function. The clinician must take a precision impres meters (Figs 12-89 to 12 -96).
sion that can be cast and duplicated several times A prosthetic team with a broad understanding of
in the laboratory to create numerous working and clinical problems and significant experience using
monitoring systems so as to maintain the precision various restorative solutions and that is always
parameters of the restoration and facilitate the clin ready to undertake restoration challenges and open
ical procedures. to innovative techniques and technologies can im-
prove the quality of the prosthetic restoration. •
Fig 12-77 Clinical situation of a bruxing patient after removal of the old prosthesis and before preprosthetic treatment of the
remaining teeth. A metal-ceramic restoration is planned for the edentulous mandibular anterior segment. Fig 12-78 Metal
ceramic restoration on the cast. Figs 12-7g D 12-81 Frontal and left and right lateral views showing the natural appearance of
the restoration and the satisfactory esthetic integration.
C H APTER 1 2
.. C O N C L U S I O N S The clinician needs to be familiar with the tech

nical process to help the dental technician fabricate
Prosthetic restoration i s a complex process that re an esthetic and functional restoration (Figs 12-77 to
q uires the use of wax, resin, and ceramic materials. 12-81). The sequence of status photographs (initial
The proposed restoration in the initial treatment clinical situation, provisional restoration in situ, cer
phase must be accepted by the patient and realized amic bisque test, and cemented ceramic material) is
as accurately as possible by the technician to avoid essential to both the laboratory work and the clinical
an unsuccessful esthetic rehabilitation. Successive re evaluation of the restoration (Figs 12-82 to 12-88).
storative stages focus on implementing a provision The ability to interpret the patient's requests
al restoration using acrylic resin, which allows the remains the most important and undoubtedly the
initial wax-based diagnostic plan to be evaluated in most difficult aspect of the entire treatment; the
vivo. The provisional restoration is followed by the success of a restoration depends on the prosthetic
development of the restoration in ceramic materiaL team's ability to realize the patient's requests while
The material that is used must provide long-term maintaining biologic, esthetic, and functional para
function. The clinician must take a precision impres meters (Figs 12-89 to 12 -96).
sion that can be cast and duplicated several times A prosthetic team with a broad understanding of
in the laboratory to create numerous working and clinical problems and significant experience using
monitoring systems so as to maintain the precision various restorative solutions and that is always
parameters of the restoration and facilitate the clin ready to undertake restoration challenges and open
ical procedures. to innovative techniques and technologies can im-
prove the quality of the prosthetic restoration. •
Fig 12-77 Clinical situation of a bruxing patient after removal of the old prosthesis and before preprosthetic treatment of the
remaining teeth. A metal-ceramic restoration is planned for the edentulous mandibular anterior segment. Fig 12-78 Metal
ceramic restoration on the cast. Figs 12-7g D 12-81 Frontal and left and right lateral views showing the natural appearance of
the restoration and the satisfactory esthetic integration.
,,-
Fig 1 2-82 Initial view of a patient who wanted an overall esthetic change of the anterior dentition without orthodontic therapy. Fig 12-83
Restoration of the maxillary anterior segment from canine to canine. Fig 1 2-84 Initial smile. Figs 12-85 to 12-87 New esthetics and dentofacial
composition i n accordance with the patient's wishes. Fig 12-88 Facial view shows esthetics of new smile and satisfaction of the young female
patient. Fig 12-8g This complex case requires restoration and redefinition of the maxillary anterior segment. including the restoration of the
length of the two central incisors. which appear to be shorter than the lateral incisors. The patient also requested tooth whitening. Fig 12-go
Definitive four ceramic veneers postcementation. Fig 12-91 Clinical situation of a young female patient requiring restoration of the right lat
eral incisor. The satisfactory approach adopted by the clinician and the effective communication of the esthetic possibilities also led to the
creation of feldspathic ceramic veneers on the central incisors. which had lost their morphology and ideal color over the years. Figs 1 2-92 and
12-93 Definitive restoration shows the new predominance of the restored central incisors compared with the complete feldspathic ceramic
crown on the right lateral incisor. Figs 12-94 and 12-95 Patient's smile before and after treatment. The restorations significantly improved the
dental esthetics as well as overall appearance. Esthetic restoration of the central incisors can positively influence self-esteem and self
acceptance. Fig 12-6 Emergence profile under the stereomicroscope. Note the excellent integration of the restored teeth at the gingival margin.
111
,,-
Fig 1 2-82 Initial view of a patient who wanted an overall esthetic change of the anterior dentition without orthodontic therapy. Fig 12-83
Restoration of the maxillary anterior segment from canine to canine. Fig 1 2-84 Initial smile. Figs 12-85 to 12-87 New esthetics and dentofacial
composition i n accordance with the patient's wishes. Fig 12-88 Facial view shows esthetics of new smile and satisfaction of the young female
patient. Fig 12-8g This complex case requires restoration and redefinition of the maxillary anterior segment. including the restoration of the
length of the two central incisors. which appear to be shorter than the lateral incisors. The patient also requested tooth whitening. Fig 12-go
Definitive four ceramic veneers postcementation. Fig 12-91 Clinical situation of a young female patient requiring restoration of the right lat
eral incisor. The satisfactory approach adopted by the clinician and the effective communication of the esthetic possibilities also led to the
creation of feldspathic ceramic veneers on the central incisors. which had lost their morphology and ideal color over the years. Figs 1 2-92 and
12-93 Definitive restoration shows the new predominance of the restored central incisors compared with the complete feldspathic ceramic
crown on the right lateral incisor. Figs 12-94 and 12-95 Patient's smile before and after treatment. The restorations significantly improved the
dental esthetics as well as overall appearance. Esthetic restoration of the central incisors can positively influence self-esteem and self
acceptance. Fig 12-6 Emergence profile under the stereomicroscope. Note the excellent integration of the restored teeth at the gingival margin.
111
CHAPTER 1 2
,- ----
�s
� th
� ti=
e� c�C
� o
� n=
s�i�
de
� r�tio
a�� n�
s fu
� r�e
� �
� m
� ic
� e=
R=st
� r�
o� io
at��n�s
j
Schwabacher WB. Goodkind Rl. Three-dimensional color 10. Romeo G. Systematics and individuality are not mutu· Magne P, Magne M, Belser U. The esthetic width in ixed
R E F E R E N CES 5· 16.
coordinates of natural teeth compared with three shade ally exclusive. Part I. Dent Dialogue 200t;2:t4rt54· prosthodontics. I Prosthodont 1999;8: t»-u8.
1. Obregon A, Goodkind Rl. Schwabacheer WB. Efects of guides. I Prosthet Dent 1990;64:425-431. 1 t. Romeo G. Systematics and individuality are not mutu· 17. Romeo G. Systematics and individuality are not mutu
opaque porcelain surface texture on the color of ceramo· 6. Hegenbarth E. Color choice procedures for ceramic restor· ally exclusive. Pat II . Dent Dialogue 2001;3:24-28. ally exclusive. Part II. Dent Dialogue 2000;6:t4-154.
metal restorations. I Prosthet Dent 198t:46:33o-340. ations ]in German]. Dent Labor 1982 ;30:1251-1255. 12. Prosper L. Light and color. MA Edition 1998; 5 : 103-138. 18. Geller W. Light and shade actions. MA Edition 1991;3:
2. Cook WD, McAree DC. Optical properties of esthetic 7. Hegenbarth E. Creative color system ]in German]. Quin· 13. Goodacre Cl. Van Roekel NB. Dykema RW, Ullman RB. 84-114-
restorative materials and natural dentition. J Biomed tessenz Zahntech 1987;13:978-991. The collartess metal-ceramic crown. J Prosthet Dent 1977; 19- Aoshima H. Brightness and texture reproduction of nat·
ater Res 1985;19:46r488. 8. Zena RE. Hegenbarth E. Transparency: The fourth chro· 38:615-62 2 . ural teeth. Quintessence lnt 1993;3:947962.
3. O'Brien WI. Double layer efect and other optical phe matic dimension [in Italian). Quintessenza Odontotecnica 1 4 . Sozio RB. The marginal aspect of the ceramo-metal 20. Goldstein RE. lancaster JS. Survey of patient attitudes
nomena related to esthetics. Dent Clin Noth Am 1985; 1994;6:537-545. restoration: The collar1ess ceramo-metal restoration. Dent toward current esthetic procedures. J Prosthet Dent 1984;
29:667-672- 9· Romeo G. Aesthetic stratiication of metal-ceramic crown Clin North Am 1977;21:787-801. 5 2 :775-78o.
4· Roge M, Preston ID. Color. light. and the perception of restorations for natural manipulation of light. Pract 15. Prince J. Donovan TE. The esthetic metal-ceramic mar
form. Quintessence lnt 1987;18:391-396. Proced Aesthet Dent 2001;5:411-415. gin: A comparison of techniques. J Prosthet Dent 1983:
50: 185-192.
CHAPTER 1 2
,- ----
�s
� th
� ti=
e� c�C
� o
� n=
s�i�
de
� r�tio
a�� n�
s fu
� r�e
� �
� m
� ic
� e=
R=st
� r�
o� io
at��n�s
j
Schwabacher WB. Goodkind Rl. Three-dimensional color 10. Romeo G. Systematics and individuality are not mutu· Magne P, Magne M, Belser U. The esthetic width in ixed
R E F E R E N CES 5· 16.
coordinates of natural teeth compared with three shade ally exclusive. Part I. Dent Dialogue 200t;2:t4rt54· prosthodontics. I Prosthodont 1999;8: t»-u8.
1. Obregon A, Goodkind Rl. Schwabacheer WB. Efects of guides. I Prosthet Dent 1990;64:425-431. 1 t. Romeo G. Systematics and individuality are not mutu· 17. Romeo G. Systematics and individuality are not mutu
opaque porcelain surface texture on the color of ceramo· 6. Hegenbarth E. Color choice procedures for ceramic restor· ally exclusive. Pat II . Dent Dialogue 2001;3:24-28. ally exclusive. Part II. Dent Dialogue 2000;6:t4-154.
metal restorations. I Prosthet Dent 198t:46:33o-340. ations ]in German]. Dent Labor 1982 ;30:1251-1255. 12. Prosper L. Light and color. MA Edition 1998; 5 : 103-138. 18. Geller W. Light and shade actions. MA Edition 1991;3:
2. Cook WD, McAree DC. Optical properties of esthetic 7. Hegenbarth E. Creative color system ]in German]. Quin· 13. Goodacre Cl. Van Roekel NB. Dykema RW, Ullman RB. 84-114-
restorative materials and natural dentition. J Biomed tessenz Zahntech 1987;13:978-991. The collartess metal-ceramic crown. J Prosthet Dent 1977; 19- Aoshima H. Brightness and texture reproduction of nat·
ater Res 1985;19:46r488. 8. Zena RE. Hegenbarth E. Transparency: The fourth chro· 38:615-62 2 . ural teeth. Quintessence lnt 1993;3:947962.
3. O'Brien WI. Double layer efect and other optical phe matic dimension [in Italian). Quintessenza Odontotecnica 1 4 . Sozio RB. The marginal aspect of the ceramo-metal 20. Goldstein RE. lancaster JS. Survey of patient attitudes
nomena related to esthetics. Dent Clin Noth Am 1985; 1994;6:537-545. restoration: The collar1ess ceramo-metal restoration. Dent toward current esthetic procedures. J Prosthet Dent 1984;
29:667-672- 9· Romeo G. Aesthetic stratiication of metal-ceramic crown Clin North Am 1977;21:787-801. 5 2 :775-78o.
4· Roge M, Preston ID. Color. light. and the perception of restorations for natural manipulation of light. Pract 15. Prince J. Donovan TE. The esthetic metal-ceramic mar
form. Quintessence lnt 1987;18:391-396. Proced Aesthet Dent 2001;5:411-415. gin: A comparison of techniques. J Prosthet Dent 1983:
50: 185-192.
--
-
C H A P T E R 1 3
C E M E N T A T I O N • • The diusion theoy is based on the adhesion cre bonding material is applied in a thin layer. it must
ated by mobile molecules located on the adhesive have a high resistance to this type of force to avoid
wh Federico Ferraris adherend interface. fracture and loss of function. In prosthetic dentisty.
the cement's capacity to withstand the tensile stress
Resin composites achieve a micromechanical adhesion that can dislocate the restoration is a matter of great
with the mineralized tissues of the tooth. whereas concen. Bonding strength normally ranges from 2
glass-ionomer cements Oike other carboxylates) use MPa for materials that do not have speciic adhesion
chemical adhesion. to 40 MPa for materials that do possess speciic ad
hesive ability. Compression strength of 31 MPa'·3 is
considered by a number of authors to be acceptable,
PRO PERTIES O F CEMENT
while the American Dental Associatio/Ameican Nation
Cement afects the durability and function of a res al Standards Institute (AD/ANSI) (speciication no.
toration to such a degree that improper use or hand 96. dated 1994) established a value of 70 MPa for all
C
ementation is the inal stage of restorative Cementation of the dental prosthesis is not nec ling of a cement can jeopardize its precision and water-based cements used in dentisty.
treatment and requires the same degree of essarily synonymous with an adhesive union between prognosis. Regardless of the type of cement. the
precision as each of the earlier stages. Cement the tooth and the restoration. Cements can provide a clinician must comply with all requirements to reduce Low VISCOSity
cannot correct errors in seating the restoration or simple bond. as exemplified by traditional zinc phos the incidence of inadequate cementation. The prop If the cement is excessively thick, precision of the
mistakes made during planning or preparation phate cements that do not have specific bonding erties of a cement can be divided into four categories: prosthetic treatment is likely to be compromised.
stages. Although this stage is critical to the deinitive properties but have been widely used for many years. mechanicophysical, biologic, working. and esthetic. Moreover, the handling and mixing of the cement can
restoration. clinical success is achieved only by adopt The dental profession continues to seek new adhesive signiicantly inRuence its viscosity and therefore its
ing an accurate overall approach. Coming as it does characteristics to improve the traditional materials. application thickness. A thick layer of cement can
Mechanicophysical properties
after so many complex prosthetic phases. cementa Adhesion refers to the bonding capacity of two alter the ratio with adjacent and opposing teeth and
tion cannot transform imprecise work into a long surfaces. the adhesive and the adherend, that come Low solubility 1n oral fluids jeopardize precise marginal closure, mechanical re
lasting esthetic restoration. into contact with each other and is the product of Once the restoration has been bonded, it must remain tention, solidity, and resistance of the cement. The
The use of cement in prosthetic dental restorations molecular interaction. Adhesive resistance is directly isolated from the oral environment for a time period cement must allow for application as a vey thin ilm.
began in the mid-19th century with a magnesium proportional to the molecular bonding strength of the determined by the type of cement used. With a high ADA speciication no. 8 and AD/ANSI specification
chloride bonding material. Some of the materials intro substances joined together.' Various theories regard ly soluble cement. even limited exposure to saliva can no. 96 established a maximum cement thickness of
duced in the early 2oth century, such as zinc phos ing the adhesion of dental structures have been cause the progressive dissolution of the cement bond. 25 �m. During fabrication of the restoration, the den
phate. zinc oxide€ugenol, and silicate-based cements, proposed': which can eventually lead to contact between oral bac tal technician should anticipate the amount of space
are still used in contemporary clinical practice. teria and the dental structure. Seconday caries and a needed for cement application and place a die spac
The cement should not be chosen until the re • The mechanical theory exploits the capacity of the change in the restoration-tooth ratios would result. er over the cast for this purpose (except in the area
storative treatment is being planned. Variables such adhesive to create interlocking bonds on the near the margin).
as the placement of the restoration, the position of rough and uneven surface of the adherend. High compression and tensile strength
the finish line, the restorative material. and the den • The absorption theory merely exploits the primary Occlusal force during mastication subjects the res Good adhesion to mineralized tissues
tal substrate on which the restoration is to be bond (as in primary and covalent bonds) and secondary toration. cement, and remaining dental structure to The concept of adhesion in dentistry was introduced
ed will help determine the type of cement that (as in dipolar interaction, Van der Waals forces, compressive stresses. The ability of a cement to with in the 1950s,4 and ater decades of innovation, adhe
should be used. However, waiting until the cementa and hydrogen bonds) types of chemical bonds that stand compressive and tensile stresses is one factor sive techniques can now be applied to many clinical
tion appointment to choose the type of cement is develop between the adhesive and adherend. . that afects long-term duration of the bond. Since the situations and achieve results that have only recently .
also a critical mistake.

--
-
C H A P T E R 1 3
C E M E N T A T I O N • • The diusion theoy is based on the adhesion cre bonding material is applied in a thin layer. it must
ated by mobile molecules located on the adhesive have a high resistance to this type of force to avoid
wh Federico Ferraris adherend interface. fracture and loss of function. In prosthetic dentisty.
the cement's capacity to withstand the tensile stress
Resin composites achieve a micromechanical adhesion that can dislocate the restoration is a matter of great
with the mineralized tissues of the tooth. whereas concen. Bonding strength normally ranges from 2
glass-ionomer cements Oike other carboxylates) use MPa for materials that do not have speciic adhesion
chemical adhesion. to 40 MPa for materials that do possess speciic ad
hesive ability. Compression strength of 31 MPa'·3 is
considered by a number of authors to be acceptable,
PRO PERTIES O F CEMENT
while the American Dental Associatio/Ameican Nation
Cement afects the durability and function of a res al Standards Institute (AD/ANSI) (speciication no.
toration to such a degree that improper use or hand 96. dated 1994) established a value of 70 MPa for all
C
ementation is the inal stage of restorative Cementation of the dental prosthesis is not nec ling of a cement can jeopardize its precision and water-based cements used in dentisty.
treatment and requires the same degree of essarily synonymous with an adhesive union between prognosis. Regardless of the type of cement. the
precision as each of the earlier stages. Cement the tooth and the restoration. Cements can provide a clinician must comply with all requirements to reduce Low VISCOSity
cannot correct errors in seating the restoration or simple bond. as exemplified by traditional zinc phos the incidence of inadequate cementation. The prop If the cement is excessively thick, precision of the
mistakes made during planning or preparation phate cements that do not have specific bonding erties of a cement can be divided into four categories: prosthetic treatment is likely to be compromised.
stages. Although this stage is critical to the deinitive properties but have been widely used for many years. mechanicophysical, biologic, working. and esthetic. Moreover, the handling and mixing of the cement can
restoration. clinical success is achieved only by adopt The dental profession continues to seek new adhesive signiicantly inRuence its viscosity and therefore its
ing an accurate overall approach. Coming as it does characteristics to improve the traditional materials. application thickness. A thick layer of cement can
Mechanicophysical properties
after so many complex prosthetic phases. cementa Adhesion refers to the bonding capacity of two alter the ratio with adjacent and opposing teeth and
tion cannot transform imprecise work into a long surfaces. the adhesive and the adherend, that come Low solubility 1n oral fluids jeopardize precise marginal closure, mechanical re
lasting esthetic restoration. into contact with each other and is the product of Once the restoration has been bonded, it must remain tention, solidity, and resistance of the cement. The
The use of cement in prosthetic dental restorations molecular interaction. Adhesive resistance is directly isolated from the oral environment for a time period cement must allow for application as a vey thin ilm.
began in the mid-19th century with a magnesium proportional to the molecular bonding strength of the determined by the type of cement used. With a high ADA speciication no. 8 and AD/ANSI specification
chloride bonding material. Some of the materials intro substances joined together.' Various theories regard ly soluble cement. even limited exposure to saliva can no. 96 established a maximum cement thickness of
duced in the early 2oth century, such as zinc phos ing the adhesion of dental structures have been cause the progressive dissolution of the cement bond. 25 �m. During fabrication of the restoration, the den
phate. zinc oxide€ugenol, and silicate-based cements, proposed': which can eventually lead to contact between oral bac tal technician should anticipate the amount of space
are still used in contemporary clinical practice. teria and the dental structure. Seconday caries and a needed for cement application and place a die spac
The cement should not be chosen until the re • The mechanical theory exploits the capacity of the change in the restoration-tooth ratios would result. er over the cast for this purpose (except in the area
storative treatment is being planned. Variables such adhesive to create interlocking bonds on the near the margin).
as the placement of the restoration, the position of rough and uneven surface of the adherend. High compression and tensile strength
the finish line, the restorative material. and the den • The absorption theory merely exploits the primary Occlusal force during mastication subjects the res Good adhesion to mineralized tissues
tal substrate on which the restoration is to be bond (as in primary and covalent bonds) and secondary toration. cement, and remaining dental structure to The concept of adhesion in dentistry was introduced
ed will help determine the type of cement that (as in dipolar interaction, Van der Waals forces, compressive stresses. The ability of a cement to with in the 1950s,4 and ater decades of innovation, adhe
should be used. However, waiting until the cementa and hydrogen bonds) types of chemical bonds that stand compressive and tensile stresses is one factor sive techniques can now be applied to many clinical
tion appointment to choose the type of cement is develop between the adhesive and adherend. . that afects long-term duration of the bond. Since the situations and achieve results that have only recently .
also a critical mistake.

CHAPTER 1 3
Cementation
. been made possible. Good cement adhesion to den B i ologic p roperties . Worki n g properties Radiographic opacity
tal structures can decrease the risk of secondary According to a number of authors,'0 a n ideal cement
caries and marginal leakage. Atoxic1ty a n d 1solat1on of the dental pulp Adequate setting time should exhibit high radiographic opacity to enable
Distinguishing between purely chemical adhesion, Preparation of a vital tooth significantly increases the The setting of the cement requires an initial period, the clinician to discern between the cement line and
a quality intrinsic to glass-ionomer cements, for exam permeability of the dentin, resulting in sensitization of when the cement is applied and the restoration seat secondary caries. However, in the present authors'
ple, and micromechanica/ adhesion, a characteristic of the prepared tooth. The clinician must use inert mate ed, and a second period, when most of the cement opinion, detection of a cement line indicates exces
resin materials associated with an enamel-dentin bond rials that do not contain toxic substances and yet molecules bond the surfaces together. sive cement thickness; radiographic opacity can reveal
ing system, is important. Micromechanical adhesion have good thermal, chemical, and electric insulating Once the components begin to react in autopoly excess material in the periodontal space in the radio
exploits microscopic retention areas created on the properties to avoid the risk of postoperative sensi merizing cement, an adequate setting time enables graphic examination (Fig 13-2}.
dental surface and subjected to a surface treatment. tivity. In removing enamel and dentin during tooth the clinician to complete the mixing and application
preparation, the clinician decreases the amount of of the cement as well as the seating of the restora
TYPES OF CEM ENT
Good adhesion to restorative materials hard tissue interposed between the oral environment tion and still have the opportunity to verify the posi
Adhesion of the cement to the material used to con· and the dental pulp, while increasing the number and tion of the restoration. Nonetheless, to comply with Dental cements are generally classified according to
struct the restoration is essential, both to prevent diameter of exposed dentinal tubules, thereby ren clinical requirements, the setting reaction must take their chemical composition, but distinctions can be
leakage and to achieve a suitable tooth-cement dering the vascular-nerve structure of the tooth more place in a relatively short period of time. For auto made on the basis of other parameters, such as the
restoration bond. A cement that adheres well to sensitive to external agents.s polymerizing cements, ADNANSI speciication no. 96 way polymerization is activated, physical characteris
m i neralized tissues does not always work with the recommends a net setting time of 2.5 to 8 minutes. tics, or intended use. Dental cements are used not
cement-restoration i nterface, even though dual ce Resistance to tooth decay Cementation also can be carried out using dual only to bond prosthetic restorations or othodontic
ment adhesion to the tooth and the internal surface The capacity of a bonding material to prevent sec polymerizing or photopolymerizing materials. Dual devices but also to protect pulp, improve the geome
of the restoration remains the ideal scenario. ondary caries correlates strictly with its solubility in polymerizing cements have an initial chemical activa try of a prosthetic site, and restore natural teeth. This
In modern dentisty it is increasingly common to the oral cavity; hence, the higher the molecular sta tion similar to that of autopolymerizing cements but chapter focuses exclusively on cements used to fix
restore teeth that have already been restored using bility, the lower the risk of bacterial iniltration. Cetain require light sources to complete the chemical reac prosthetic restorations. A further distinction must be
glass-ionomer cement, resin composite, amalgam, or cements (eg, glass-ionomers} have intrinsic fluoride tions. Photopolymerizing cements rely on a light· made between cements for provisional and perma
gold alloy. Evaluating pre-existing restorative materi releasing properties that reduce the carioreceptivity of activation to cure, thereby enabling the clinician to nent bonding, the latter of which must maintain the
als is important for selecting an appropriate bonding the tooth_6.7 manage the cementation setting times to suit the restoration in the correct position as long as possible
cement. clinical situation. and in the most stable way possible. Classification
Absence of microleakage based on the chemical composition2 divides cements
Low water absorption A material suited to cementation must ensure a pre into four principal families:
Esthetic properties
Cement must have low water absorption to avoid cise and stable marginal seal. Microleakage at the
changes i n structure and volume, which can negative cement-tooth interface is unfavorable to the longevity Chromatic stability Phosphates
ly impact prosthetic function. of the restoration and can lead to demineralization of The esthetics of a cement are vey important for res • Zinc phosphate
torations using translucent materials without opaque • Zinc silicate phosphate
the tooth structure. ..
substructures. The capacity of a cement to maintain
esthetic characteristics over time8·9 is critical. Cement Phenolates
with poor chromatic properties used in a restorative • Zinc oxide-eugenol (ZOE}: ZOE + polymer and ZOE
treatment of feldspathic ceramic material, for exam + ethoxybenzoic acid (EBA} and alumina
ple, seriously reduces the esthetics of the definitive • Calcium hydroxide salicylate ..
restoration (Fig 13-1}.
07
CHAPTER 1 3
Cementation
. been made possible. Good cement adhesion to den B i ologic p roperties . Worki n g properties Radiographic opacity
tal structures can decrease the risk of secondary According to a number of authors,'0 a n ideal cement
caries and marginal leakage. Atoxic1ty a n d 1solat1on of the dental pulp Adequate setting time should exhibit high radiographic opacity to enable
Distinguishing between purely chemical adhesion, Preparation of a vital tooth significantly increases the The setting of the cement requires an initial period, the clinician to discern between the cement line and
a quality intrinsic to glass-ionomer cements, for exam permeability of the dentin, resulting in sensitization of when the cement is applied and the restoration seat secondary caries. However, in the present authors'
ple, and micromechanica/ adhesion, a characteristic of the prepared tooth. The clinician must use inert mate ed, and a second period, when most of the cement opinion, detection of a cement line indicates exces
resin materials associated with an enamel-dentin bond rials that do not contain toxic substances and yet molecules bond the surfaces together. sive cement thickness; radiographic opacity can reveal
ing system, is important. Micromechanical adhesion have good thermal, chemical, and electric insulating Once the components begin to react in autopoly excess material in the periodontal space in the radio
exploits microscopic retention areas created on the properties to avoid the risk of postoperative sensi merizing cement, an adequate setting time enables graphic examination (Fig 13-2}.
dental surface and subjected to a surface treatment. tivity. In removing enamel and dentin during tooth the clinician to complete the mixing and application
preparation, the clinician decreases the amount of of the cement as well as the seating of the restora
TYPES OF CEM ENT
Good adhesion to restorative materials hard tissue interposed between the oral environment tion and still have the opportunity to verify the posi
Adhesion of the cement to the material used to con· and the dental pulp, while increasing the number and tion of the restoration. Nonetheless, to comply with Dental cements are generally classified according to
struct the restoration is essential, both to prevent diameter of exposed dentinal tubules, thereby ren clinical requirements, the setting reaction must take their chemical composition, but distinctions can be
leakage and to achieve a suitable tooth-cement dering the vascular-nerve structure of the tooth more place in a relatively short period of time. For auto made on the basis of other parameters, such as the
restoration bond. A cement that adheres well to sensitive to external agents.s polymerizing cements, ADNANSI speciication no. 96 way polymerization is activated, physical characteris
m i neralized tissues does not always work with the recommends a net setting time of 2.5 to 8 minutes. tics, or intended use. Dental cements are used not
cement-restoration i nterface, even though dual ce Resistance to tooth decay Cementation also can be carried out using dual only to bond prosthetic restorations or othodontic
ment adhesion to the tooth and the internal surface The capacity of a bonding material to prevent sec polymerizing or photopolymerizing materials. Dual devices but also to protect pulp, improve the geome
of the restoration remains the ideal scenario. ondary caries correlates strictly with its solubility in polymerizing cements have an initial chemical activa try of a prosthetic site, and restore natural teeth. This
In modern dentisty it is increasingly common to the oral cavity; hence, the higher the molecular sta tion similar to that of autopolymerizing cements but chapter focuses exclusively on cements used to fix
restore teeth that have already been restored using bility, the lower the risk of bacterial iniltration. Cetain require light sources to complete the chemical reac prosthetic restorations. A further distinction must be
glass-ionomer cement, resin composite, amalgam, or cements (eg, glass-ionomers} have intrinsic fluoride tions. Photopolymerizing cements rely on a light· made between cements for provisional and perma
gold alloy. Evaluating pre-existing restorative materi releasing properties that reduce the carioreceptivity of activation to cure, thereby enabling the clinician to nent bonding, the latter of which must maintain the
als is important for selecting an appropriate bonding the tooth_6.7 manage the cementation setting times to suit the restoration in the correct position as long as possible
cement. clinical situation. and in the most stable way possible. Classification
Absence of microleakage based on the chemical composition2 divides cements
Low water absorption A material suited to cementation must ensure a pre into four principal families:
Esthetic properties
Cement must have low water absorption to avoid cise and stable marginal seal. Microleakage at the
changes i n structure and volume, which can negative cement-tooth interface is unfavorable to the longevity Chromatic stability Phosphates
ly impact prosthetic function. of the restoration and can lead to demineralization of The esthetics of a cement are vey important for res • Zinc phosphate
torations using translucent materials without opaque • Zinc silicate phosphate
the tooth structure. ..
substructures. The capacity of a cement to maintain
esthetic characteristics over time8·9 is critical. Cement Phenolates
with poor chromatic properties used in a restorative • Zinc oxide-eugenol (ZOE}: ZOE + polymer and ZOE
treatment of feldspathic ceramic material, for exam + ethoxybenzoic acid (EBA} and alumina
ple, seriously reduces the esthetics of the definitive • Calcium hydroxide salicylate ..
restoration (Fig 13-1}.
07
CHAPTER 1 3
n
��-----�C�e�m��e�n=ta�ti�o�
. Polycarboxylates • Glass-ionomer cements: Ketac Cen (3M ESPE). Fuji

• Zinc polycarboxylate I (GC), Glaslonomer Cement (Shofu), AquaCem
• Glass ionomer: conventional and resin rein forced (DeTrey Dentsply) (Fig 13-4)
• Resin-modified glass-ionomer cements: Fuji Plus
Acylates (previously Fuji Duet; GO. Fuji Cen (GC). RelyX FIG 13-1 FIG 13-2
• Polymethylacrylate (resin) Luting Cement (previously Vitremer; 3M ESPE) (Fig
• Dimethylacrylate (resin): filled and unfilled 13·sl
• Adhesive resin cements: RelyX ARC (3M ESPE).
However, for the purposes of this chapter, the authors RelyX Unicem (3M ESPE). Variolink I I (lvoclar Viva·
propose a simplified classification appropriate for clini· dent), Panavia F (Kuraray), Panavia 21 (Kuraray).
cal application: C&B Superbond (Sun Medical) (Fig 13-6)
• Zinc phosphate cements

• ZOE cements C L I N ICAL P R O B L E M S
• Zinc polycarboxylate cements (zinc polyacrylate) A N D SOLUT I O N S
• Glass-ionomer cements
FIG 13-3 FIG 13-4
• Resin-modified glass-ionomer cements (hybrid
Exerting pressure t o seat t h e
ionomers)
restoration
• Adhesive resin cements
The restoration must be properly seated on the pre
pared tooth during final cementation, not only in rela·
Comm ercial products
tion to the space ratio with adjacent and opposing
Following are commercially available cements listed teeth but also to comply with the occlusal parameters
according to the types primarily used in clinical den and to avoid compromising the work completed to
tistry. this point.
Cement impedes positioning or the restoration
• Zinc phosphate cements: Harvard Cement (Richter because it exerts resistance during seating; therefore,
and Hofmann), SC Cement (Stratford-Cookson). Reeks the clinician must exert suficient pressure to over· FIG 13-5 FIG 13-6
(Mizzy), zinc phosphate cement (DeTrey Dentsply) come this resistance. A study" evaluated the hydro·
(Fig 13·3) static pressure required when cementing posts with
• ZOE cements: TempBond (Kerr Hawe) three different types or cement: zinc phosphate, glass
• ZOE-free cements: Pro-cen (3M ESPE), Provicol ionomer, and adhesive resin. The pressure necessary
(VOCO), TempBond NE and TempBond Clear (Kerr to ensure the correct positioning was equal to 22.67 Fig 13-1 Chroma of polymerized cements, (let to righ/ glass 1onomer. hybrid glass ion � mer. resin cement. transparent restorative composite
Hawe). Freegenol Temporay Pack (GO psi for the zinc phosphate, 19.97 psi for the resin, Even though the first three cements are white. they are only su1table for restorations With an opaque core (eg. metal. atum1nal and would alter
the final esthetics if used with a translucent restoration The transparent hnmall compoSite appears neutral and IS therefore 1deal when
• Zinc carboxylate cements: Durelon (3M ESPE), and 17.66 psi for the glass-ionomer cement; therefore cementing translucent restorations.
Poly-F Plus (previously Bondex; DeTrey Dentsply), the latter cement was round to be the easiest and Fig 13-2 Radiograph of a zinc phosphate cement specimen and an extracted tooth. The marked radiographic opac�ty can be appreciated with
reference to the hard tissues of the tooth.
carboxylate (Heraeus Kulzer) safest for seating a restoration. The greater the pres·
Fig 13-3 Zinc phosphate (Harvard Cement and SC Cement) is the oldest and still the most common cement used today
sure exerted during positioning, the thinner the
Fig 13-4 Glass ionomer (Ketac Cem).
cement line that results.12 . Fig 13-5 Resin-reinforce d glass 1onomer (FujiCem).
Fig 13-6 Adhesive resin cement (Panam Fl
CHAPTER 1 3
n
��-----�C�e�m��e�n=ta�ti�o�
. Polycarboxylates • Glass-ionomer cements: Ketac Cen (3M ESPE). Fuji

• Zinc polycarboxylate I (GC), Glaslonomer Cement (Shofu), AquaCem
• Glass ionomer: conventional and resin rein forced (DeTrey Dentsply) (Fig 13-4)
• Resin-modified glass-ionomer cements: Fuji Plus
Acylates (previously Fuji Duet; GO. Fuji Cen (GC). RelyX FIG 13-1 FIG 13-2
• Polymethylacrylate (resin) Luting Cement (previously Vitremer; 3M ESPE) (Fig
• Dimethylacrylate (resin): filled and unfilled 13·sl
• Adhesive resin cements: RelyX ARC (3M ESPE).
However, for the purposes of this chapter, the authors RelyX Unicem (3M ESPE). Variolink I I (lvoclar Viva·
propose a simplified classification appropriate for clini· dent), Panavia F (Kuraray), Panavia 21 (Kuraray).
cal application: C&B Superbond (Sun Medical) (Fig 13-6)
• Zinc phosphate cements

• ZOE cements C L I N ICAL P R O B L E M S
• Zinc polycarboxylate cements (zinc polyacrylate) A N D SOLUT I O N S
• Glass-ionomer cements
FIG 13-3 FIG 13-4
• Resin-modified glass-ionomer cements (hybrid
Exerting pressure t o seat t h e
ionomers)
restoration
• Adhesive resin cements
The restoration must be properly seated on the pre
pared tooth during final cementation, not only in rela·
Comm ercial products
tion to the space ratio with adjacent and opposing
Following are commercially available cements listed teeth but also to comply with the occlusal parameters
according to the types primarily used in clinical den and to avoid compromising the work completed to
tistry. this point.
Cement impedes positioning or the restoration
• Zinc phosphate cements: Harvard Cement (Richter because it exerts resistance during seating; therefore,
and Hofmann), SC Cement (Stratford-Cookson). Reeks the clinician must exert suficient pressure to over· FIG 13-5 FIG 13-6
(Mizzy), zinc phosphate cement (DeTrey Dentsply) come this resistance. A study" evaluated the hydro·
(Fig 13·3) static pressure required when cementing posts with
• ZOE cements: TempBond (Kerr Hawe) three different types or cement: zinc phosphate, glass
• ZOE-free cements: Pro-cen (3M ESPE), Provicol ionomer, and adhesive resin. The pressure necessary
(VOCO), TempBond NE and TempBond Clear (Kerr to ensure the correct positioning was equal to 22.67 Fig 13-1 Chroma of polymerized cements, (let to righ/ glass 1onomer. hybrid glass ion � mer. resin cement. transparent restorative composite
Hawe). Freegenol Temporay Pack (GO psi for the zinc phosphate, 19.97 psi for the resin, Even though the first three cements are white. they are only su1table for restorations With an opaque core (eg. metal. atum1nal and would alter
the final esthetics if used with a translucent restoration The transparent hnmall compoSite appears neutral and IS therefore 1deal when
• Zinc carboxylate cements: Durelon (3M ESPE), and 17.66 psi for the glass-ionomer cement; therefore cementing translucent restorations.
Poly-F Plus (previously Bondex; DeTrey Dentsply), the latter cement was round to be the easiest and Fig 13-2 Radiograph of a zinc phosphate cement specimen and an extracted tooth. The marked radiographic opac�ty can be appreciated with
reference to the hard tissues of the tooth.
carboxylate (Heraeus Kulzer) safest for seating a restoration. The greater the pres·
Fig 13-3 Zinc phosphate (Harvard Cement and SC Cement) is the oldest and still the most common cement used today
sure exerted during positioning, the thinner the
Fig 13-4 Glass ionomer (Ketac Cem).
cement line that results.12 . Fig 13-5 Resin-reinforce d glass 1onomer (FujiCem).
Fig 13-6 Adhesive resin cement (Panam Fl
CHA�,
_ ..
_
_ ___ _.
,
:
�---e�
Once the restoration has been placed, relying on ing the periodontal t1ssues. and the permanent .. polycarboxylates. and glass ionomers." Finally, a ret· restoration. and the restoration is inserted d ire<tly.
the patient's occlusal force or a soft wooden stick cementation must be completed as early as pos respective analysis of 1,847 restored teeth consid· Care should be taken to remove the excess material
interposed between the teeth is insuficient to guar sible. ered the use of diferent cementation materials indi after sening is complete.
antee definitive seating. Some authors recommend • The smear layer must be removed after tooth cating precise protocols for the bonding procedure,
ultrasonic vibration." but excessive usage (more preparation has been completed. and the dentin and no signiicant postoperative sensitivity was iden Eugenol- free cements
than 1 minute for zinc phosphate, more than 5 min must be conditioned with a n antibacterial solu tified. This study concluded that compliance with cor· These cements are suitable for patients who are sen
utes for adhesive resins and glass ionomers) can tion before the tooth is provisionally restored. rect cementation procedures decreases the risks of sitive to eugenol or for cases in which the deinitive
decrease adhesive strengt h '3 When cementing a • The dentin should be protected with a liner that sensitization problems. o cementation will use resin materials exploiting micro
prosthetic restoration, the authors of this text prefer can be readily removed before the definitive ce· mechanical adhesion. Eugenol-free zinc oxid�based
to exert strong pressure diredly and repeatedly on mentation to decrease dentinal permeability. and resin-based cements are available in opaque and
CLI N I CAL PROCEDURES
the restoration rather than relying on the patient's • The dentin should be cleaned careully and remain transparent chromas.
occlusal force. moist u p to the time of cementation to ensure The clinician generally uses an adhesive solution
P rovis ional cementation
optimum micromechanical adhesion. to provisionally bond translucent acylic resin restora
• The occlusion should be checked carefully before A provisional cement must meet two requirements: tions (eg, ceramic veneers). The interior of the provi
Postoperative sensitivity
cementation. (t) it must withstand the forces that are exerted to sional restoration is etched with othophosphoric acid.
Postoperative sensitivity of a vital tooth prepared dislocate the provisional restoration while still allow and liquid resin is spread over both the prepared
for a complete crown can be a serious clinical prob If a micromechanical adhesive cementation using ing the operator to remove the restoration without tooth surface and inside the provisional restoration.
lem, as indicated by a pulpal necrosis rate between a resin-based system is chosen, the clinician should excessive diiculty during each operational phase, The resin cement is polymerized using a lamp. When
3% and 25%.' This complication as reported in the create a dentin-resin hybrid layer after dental prepa· and (2) it must serve as a barrier between the pre· extensive dentinal exposure occurs during prepara
dental literature is related to both the type of ce ration to ensure dentinal isolation. Micromechanical pared tooth and the oral environment. tion, the clinician must hybridize the dentin" and then
ment used and the treatment of the exposed dentin.•s adhesion represents a preservation method against bond the provisional restoration with provisional trans
However, the present authors are convinced that the pulpal irritations.'' An in vivo analysis'8 with a ZOE cements parent resin cement (eg, TempBond Clear) (Fig t3·7l -
principal cause of pulpal injury following cementa· follow-up period of 17.3 months ater cementation The clinician can suiciently isolate the operating
tion is traumatic dental preparation, frequently the showed no significant sensitivity events ater either field for cementation with this material by suctioning Permanent cementation
consequence of excess wear of the abrasive burs zinc phosphate cements or hybrid glass-ionomer the saliva, using manual retractors for the cheeks and
(see chapter 3). cement were used to place complete crowns, veneers, tongue, and using a light air jet to dry the areas on The preparatory phases that are common to all types
Postoperative sensitivity must not be neglected or crowns serving as a partial denture. which the provisional cementation will be implement of cement used for prosthetic cementation are sum
because, in addition to patient discomfort, it can lead A study carried out over 5 years on 1,435 restora ed. Because the mixing process is not exothermic. the marized below.
to tooth necrosis.'6 The clinician can avoid many tions cemented with glass ionomer showed an use of a cold plate (or glass support) is unnecessary,
problems related to postoperative sensitivity by using acceptable compatibility with the pulpal tissues.'9 and a paper support with detachable sheets can be Removal of the provisional restoration
each cement according to its recommendations and whereas other reports have indicated the possibility used instead. The mixing process is carried out in Prior to permanent cementation, the provisional res
by following a strid protocol during preparation and of sensitivity after cementation with zinc phosphate accordance with the manufacturer's instructions. The toration must be removed with the use of special
conditioning of the tooth surface. Brannstr6m's sug and glass-ionomer cement.'6 Some authors identiy two pastes are mixed for about 30 seconds, continu strong-grip forceps (Asa Dental) (Fig 13-8) for single
gests a number of clinical rules to limit the risks of the acidity expressed by glass-ionomer cements as a ing with a spatula until the cement attains a creamy restorations and manual or mechanically operated ex
sensitivity: possible cause of pulpal irritation, 20 whereas in consistency. (Orange oil-based products can be used traders (Corona tex. KaVo; Trend, Anthogyr) (Fig 13-9)
other studies no significant differences have been to clean the spatula and remove cement residue.) A for fixed partial dentures or combined restorations. ..
• The provisional restoration must be precise and identified i n terms of the histologic response of the very small amount of the material is placed inside the
correctly achieve marginal closure without agitat· pulp ater cementation with zinc phosphates, zinc ..
411
CHA�,
_ ..
_
_ ___ _.
,
:
�---e�
Once the restoration has been placed, relying on ing the periodontal t1ssues. and the permanent .. polycarboxylates. and glass ionomers." Finally, a ret· restoration. and the restoration is inserted d ire<tly.
the patient's occlusal force or a soft wooden stick cementation must be completed as early as pos respective analysis of 1,847 restored teeth consid· Care should be taken to remove the excess material
interposed between the teeth is insuficient to guar sible. ered the use of diferent cementation materials indi after sening is complete.
antee definitive seating. Some authors recommend • The smear layer must be removed after tooth cating precise protocols for the bonding procedure,
ultrasonic vibration." but excessive usage (more preparation has been completed. and the dentin and no signiicant postoperative sensitivity was iden Eugenol- free cements
than 1 minute for zinc phosphate, more than 5 min must be conditioned with a n antibacterial solu tified. This study concluded that compliance with cor· These cements are suitable for patients who are sen
utes for adhesive resins and glass ionomers) can tion before the tooth is provisionally restored. rect cementation procedures decreases the risks of sitive to eugenol or for cases in which the deinitive
decrease adhesive strengt h '3 When cementing a • The dentin should be protected with a liner that sensitization problems. o cementation will use resin materials exploiting micro
prosthetic restoration, the authors of this text prefer can be readily removed before the definitive ce· mechanical adhesion. Eugenol-free zinc oxid�based
to exert strong pressure diredly and repeatedly on mentation to decrease dentinal permeability. and resin-based cements are available in opaque and
CLI N I CAL PROCEDURES
the restoration rather than relying on the patient's • The dentin should be cleaned careully and remain transparent chromas.
occlusal force. moist u p to the time of cementation to ensure The clinician generally uses an adhesive solution
P rovis ional cementation
optimum micromechanical adhesion. to provisionally bond translucent acylic resin restora
• The occlusion should be checked carefully before A provisional cement must meet two requirements: tions (eg, ceramic veneers). The interior of the provi
Postoperative sensitivity
cementation. (t) it must withstand the forces that are exerted to sional restoration is etched with othophosphoric acid.
Postoperative sensitivity of a vital tooth prepared dislocate the provisional restoration while still allow and liquid resin is spread over both the prepared
for a complete crown can be a serious clinical prob If a micromechanical adhesive cementation using ing the operator to remove the restoration without tooth surface and inside the provisional restoration.
lem, as indicated by a pulpal necrosis rate between a resin-based system is chosen, the clinician should excessive diiculty during each operational phase, The resin cement is polymerized using a lamp. When
3% and 25%.' This complication as reported in the create a dentin-resin hybrid layer after dental prepa· and (2) it must serve as a barrier between the pre· extensive dentinal exposure occurs during prepara
dental literature is related to both the type of ce ration to ensure dentinal isolation. Micromechanical pared tooth and the oral environment. tion, the clinician must hybridize the dentin" and then
ment used and the treatment of the exposed dentin.•s adhesion represents a preservation method against bond the provisional restoration with provisional trans
However, the present authors are convinced that the pulpal irritations.'' An in vivo analysis'8 with a ZOE cements parent resin cement (eg, TempBond Clear) (Fig t3·7l -
principal cause of pulpal injury following cementa· follow-up period of 17.3 months ater cementation The clinician can suiciently isolate the operating
tion is traumatic dental preparation, frequently the showed no significant sensitivity events ater either field for cementation with this material by suctioning Permanent cementation
consequence of excess wear of the abrasive burs zinc phosphate cements or hybrid glass-ionomer the saliva, using manual retractors for the cheeks and
(see chapter 3). cement were used to place complete crowns, veneers, tongue, and using a light air jet to dry the areas on The preparatory phases that are common to all types
Postoperative sensitivity must not be neglected or crowns serving as a partial denture. which the provisional cementation will be implement of cement used for prosthetic cementation are sum
because, in addition to patient discomfort, it can lead A study carried out over 5 years on 1,435 restora ed. Because the mixing process is not exothermic. the marized below.
to tooth necrosis.'6 The clinician can avoid many tions cemented with glass ionomer showed an use of a cold plate (or glass support) is unnecessary,
problems related to postoperative sensitivity by using acceptable compatibility with the pulpal tissues.'9 and a paper support with detachable sheets can be Removal of the provisional restoration
each cement according to its recommendations and whereas other reports have indicated the possibility used instead. The mixing process is carried out in Prior to permanent cementation, the provisional res
by following a strid protocol during preparation and of sensitivity after cementation with zinc phosphate accordance with the manufacturer's instructions. The toration must be removed with the use of special
conditioning of the tooth surface. Brannstr6m's sug and glass-ionomer cement.'6 Some authors identiy two pastes are mixed for about 30 seconds, continu strong-grip forceps (Asa Dental) (Fig 13-8) for single
gests a number of clinical rules to limit the risks of the acidity expressed by glass-ionomer cements as a ing with a spatula until the cement attains a creamy restorations and manual or mechanically operated ex
sensitivity: possible cause of pulpal irritation, 20 whereas in consistency. (Orange oil-based products can be used traders (Corona tex. KaVo; Trend, Anthogyr) (Fig 13-9)
other studies no significant differences have been to clean the spatula and remove cement residue.) A for fixed partial dentures or combined restorations. ..
• The provisional restoration must be precise and identified i n terms of the histologic response of the very small amount of the material is placed inside the
correctly achieve marginal closure without agitat· pulp ater cementation with zinc phosphates, zinc ..
411
• Clean m g the prepared tooth lsolatton of the operat1ng f1eld
The prepared tooth is cleaned using sharp hand During cementation, the operating ield must be iso
instruments, along with prophylaxiS brushes and lated against moisture. and rubber dam is generally
abrasive substances (ie, pumice or prophylaxis paste) the optimum solution. Use of rubber dam is recom
or airborne-particle abrasion. The latter involves an mended during cementation with resin materials
air jet with an intraoral sandblasting instrument (Figs 13·1o to 13-12).
(CoJet, 3M ESPE) that uses 50-�m-diameter aluminum However, for restorations with intrasulcular mar·
dioxide particles or sodium bicarbonate particles gins, the clinician must also use cotton rolls to push
(Prophylex, KaVo). When using aluminum dioxide away the cheek and tongue and to block the excre
particles, the nose and eyes of both the patient and toy ducts of the submandibular and sublingual sali
the operator should be protected with mask and vary glands. Cotton rolls can be placed i n the buc
goggles, and the operating ield should be isolated cal areas, and special insulating disks (Dry-tips,
with rubber dam. The authors do not use this method Molnlycke) positioned close to the excretory ducts of
to clean the tooth because it is too invasive. the parotid gland, near the irst and second molars
in the internal part of the cheek, can be used for the
Restorative dimensional test maxillary arch.
Once the restoration has been fabricated and test
ed, the clinician checks it one last time before Cement mix1ng
cementation to verify the correct position on the The preferred method for mixing or activating the
preparation, the suitability of the contact points, cement varies depending on the type used. The
and the interaction with the antagonist teeth during authors prefer to use a mechanical mixing system
functional movements and maximum intercuspation whenever possible because a completely manual
(using 40-�m-thick aticulation cards [Bausch[ and technique leaves more opportunity for operator
Bo-mm-thick lateral excursion and protrusion cards). related errors.
Reflecting periodontal !issues Cement application a n d seating of the

When placing complete crowns that have an intra restoration
sulcular margin, a nonimpregnated retraction cord One of the major problems in cementation is deter·
(ooUltrapak, Ultradent) or a 2/o simple suture thread mining the quantity of cement to use. The thickness
is used to slightly retract the soft tissues at the of the application should be equal to the die spac
cervical margin. This provides better access to the er that the dental technician applies on the working
margin at the conclusion of the preparatory phase, preparation (about 25 �m). The clinician must rely
as well as when removing excess cement from the on sensation and experience since 25 �m is almost
gingival sulcus to prevent secondary inflammation. impossible to measure. Fig 13-7 Transparent provisional cement (TempBond Clear) for provisional veneers. The transparent cement is eff � ctive under
_
thin restorations. allowing light to pass through for natural esthehcs. S1nce the cement 1s eugenol free. there IS no sk of
Moreover, an intrasulcular thread absorbs crevicular Another area of concern is determining where the partially inhibiting adhesion. Fig 13-B Forceps IAsa Dental) used to remove single provisional restorations. The forceps can
luid, which can patially condition the correct set cement should be applied: on the tooth preparation overcome the retention force of the bonding cement. Fig 13-9 Mechanical extractor fitted on a low-speed handpiece. The
handpiece regulates the intensity and frequency to remove a multi-unit provisional restoration. Figs 13-10 o 13-12
ting reaction of the cement. and inside a portion of the shoulder; inside the . Cementation of two ceramic veneers on lateral incisors with a conical shape. Fig 13-10 Isolation of the operating field with
rubber dam from premolar to premolar. An interdental noose of waxed floss is positioned over the prepared teeth. Figs 13- 1 1
and 13-12 Clinical result with t h e veneers in place.
412
• Clean m g the prepared tooth lsolatton of the operat1ng f1eld
The prepared tooth is cleaned using sharp hand During cementation, the operating ield must be iso
instruments, along with prophylaxiS brushes and lated against moisture. and rubber dam is generally
abrasive substances (ie, pumice or prophylaxis paste) the optimum solution. Use of rubber dam is recom
or airborne-particle abrasion. The latter involves an mended during cementation with resin materials
air jet with an intraoral sandblasting instrument (Figs 13·1o to 13-12).
(CoJet, 3M ESPE) that uses 50-�m-diameter aluminum However, for restorations with intrasulcular mar·
dioxide particles or sodium bicarbonate particles gins, the clinician must also use cotton rolls to push
(Prophylex, KaVo). When using aluminum dioxide away the cheek and tongue and to block the excre
particles, the nose and eyes of both the patient and toy ducts of the submandibular and sublingual sali
the operator should be protected with mask and vary glands. Cotton rolls can be placed i n the buc
goggles, and the operating ield should be isolated cal areas, and special insulating disks (Dry-tips,
with rubber dam. The authors do not use this method Molnlycke) positioned close to the excretory ducts of
to clean the tooth because it is too invasive. the parotid gland, near the irst and second molars
in the internal part of the cheek, can be used for the
Restorative dimensional test maxillary arch.
Once the restoration has been fabricated and test
ed, the clinician checks it one last time before Cement mix1ng
cementation to verify the correct position on the The preferred method for mixing or activating the
preparation, the suitability of the contact points, cement varies depending on the type used. The
and the interaction with the antagonist teeth during authors prefer to use a mechanical mixing system
functional movements and maximum intercuspation whenever possible because a completely manual
(using 40-�m-thick aticulation cards [Bausch[ and technique leaves more opportunity for operator
Bo-mm-thick lateral excursion and protrusion cards). related errors.
Reflecting periodontal !issues Cement application a n d seating of the

When placing complete crowns that have an intra restoration
sulcular margin, a nonimpregnated retraction cord One of the major problems in cementation is deter·
(ooUltrapak, Ultradent) or a 2/o simple suture thread mining the quantity of cement to use. The thickness
is used to slightly retract the soft tissues at the of the application should be equal to the die spac
cervical margin. This provides better access to the er that the dental technician applies on the working
margin at the conclusion of the preparatory phase, preparation (about 25 �m). The clinician must rely
as well as when removing excess cement from the on sensation and experience since 25 �m is almost
gingival sulcus to prevent secondary inflammation. impossible to measure. Fig 13-7 Transparent provisional cement (TempBond Clear) for provisional veneers. The transparent cement is eff � ctive under
_
thin restorations. allowing light to pass through for natural esthehcs. S1nce the cement 1s eugenol free. there IS no sk of
Moreover, an intrasulcular thread absorbs crevicular Another area of concern is determining where the partially inhibiting adhesion. Fig 13-B Forceps IAsa Dental) used to remove single provisional restorations. The forceps can
luid, which can patially condition the correct set cement should be applied: on the tooth preparation overcome the retention force of the bonding cement. Fig 13-9 Mechanical extractor fitted on a low-speed handpiece. The
handpiece regulates the intensity and frequency to remove a multi-unit provisional restoration. Figs 13-10 o 13-12
ting reaction of the cement. and inside a portion of the shoulder; inside the . Cementation of two ceramic veneers on lateral incisors with a conical shape. Fig 13-10 Isolation of the operating field with
rubber dam from premolar to premolar. An interdental noose of waxed floss is positioned over the prepared teeth. Figs 13- 1 1
and 13-12 Clinical result with t h e veneers in place.
412
Cementation
. crown (Figs 13-13 to 13· 16); only on the prepared best possible marginal adaptation. Care must be
tooth; or on the prepared tooth and inside the taken to avoid moving the prosthesis once the cor
crown. The authors spread cement only on the sur rect position has been found.
face of the tooth preparation for simple cases of The formation of beads of excess cement around
cementation (one to three crowns) (Fig 13-17) - not the cement line indicates close adaptation of the
inside the crown, and never on the margin of the restoration margin with the underlying tooth and
prosthesis. However, when several restorations are hence optimum cementation (Figs 13-19 and 13-20).
cemented, they reduce the quantity of cement on The clinician must then wait until the cement has set.
the surface of prepared teeth and apply a portion of
cement inside the prosthesis at the base, taking
Removi ng excess cement
care not to trap air.
The authors oppose the concept of applying ce· Any excess cement expelled during the cementation
ment at the cevical margin since the technician does technique must be removed with care using a sharp
not apply the die spacer on the edge when the pros explorer, universal curettes (for the retraction cord),
thesis is produced. In this scenario, at least 25 �m and scrapers or unwaxed interdental floss (for the
of the margin would be exposed after cementation, interproximal areas) (Figs 13-21 to 13-26). The meth·
and possibly more depending on the amount of ads and timelines for removing excess cement de
cement introduced and the force exerted during pend on the type of cement that is used.
adaptation. Placing cement on top of the tooth prep
aration and at the restoration margin defies the logic
Checki n g the occlusion
of prosthesis fabrication, especially since the latter
would obstruct the air that escapes during adapta· The occlusion is rechecked after all of the excess
tion and raise the occlusal level of the restoration cement has been removed and suficient time has
(Fig 13·18). elapsed for the cement to complete the setting reac
When inserting the restoration, the clinician must tions. During this examination, the patient executes
use a foward-and-backward movement while exert· closure as well as protrusive and lateral excursive
ing signiicant continuous pressure. The clinician pro movements while the clinician checks for premature
ceeds in this way to give the cement an escape route contacts or interferences. .
and because the crown must be seated with the
. . . '
1 3· 2 0
igs 1 3� 13 to 13-16 Placement of excess cement inside the crown often stems from a fear of not applying a sufficient amount. ment. without exceeding the limit. t o allow air t o escape a n d t o spread the cement over the internal portion o f the restoration
whiCh 1s a rare occurrence. Figs 13-13 and 13-14 Excess cement before and after seating of the restoration on an extracted and along the preparation walls. Fig 13-18 After adapting and checking the correct seating. the operating field is isolated with
tooth. Fig 13-15 Reduced cement application. only in the internal portion. Fig 13-16 Optimum cementation after adaptation is tinfoil. and a piece of soft balsa wood is positioned between the crown and the antagonist teeth. Figs 13-1 g and 13-20 After
confirmed by minimal excess and beads of cement at the margin ion an extracted tooth). Fig 13-17 Retraction cord of the cementation with zinc phosphate. excess cement forms small beads rather than a consistent line around the entire margin
smallest diameter possible is Inserted to maintain margin accessibility. Ideal cement application on the tooth preparation circumference Bead formation indicates that cementation has occurred and that there is close contact between the metal and
should be equivalent to the die spacer. When adapting the crown. the clinician should exert a forward-and- backward move· the underlying prepared tooth.
415
Cementation
. crown (Figs 13-13 to 13· 16); only on the prepared best possible marginal adaptation. Care must be
tooth; or on the prepared tooth and inside the taken to avoid moving the prosthesis once the cor
crown. The authors spread cement only on the sur rect position has been found.
face of the tooth preparation for simple cases of The formation of beads of excess cement around
cementation (one to three crowns) (Fig 13-17) - not the cement line indicates close adaptation of the
inside the crown, and never on the margin of the restoration margin with the underlying tooth and
prosthesis. However, when several restorations are hence optimum cementation (Figs 13-19 and 13-20).
cemented, they reduce the quantity of cement on The clinician must then wait until the cement has set.
the surface of prepared teeth and apply a portion of
cement inside the prosthesis at the base, taking
Removi ng excess cement
care not to trap air.
The authors oppose the concept of applying ce· Any excess cement expelled during the cementation
ment at the cevical margin since the technician does technique must be removed with care using a sharp
not apply the die spacer on the edge when the pros explorer, universal curettes (for the retraction cord),
thesis is produced. In this scenario, at least 25 �m and scrapers or unwaxed interdental floss (for the
of the margin would be exposed after cementation, interproximal areas) (Figs 13-21 to 13-26). The meth·
and possibly more depending on the amount of ads and timelines for removing excess cement de
cement introduced and the force exerted during pend on the type of cement that is used.
adaptation. Placing cement on top of the tooth prep
aration and at the restoration margin defies the logic
Checki n g the occlusion
of prosthesis fabrication, especially since the latter
would obstruct the air that escapes during adapta· The occlusion is rechecked after all of the excess
tion and raise the occlusal level of the restoration cement has been removed and suficient time has
(Fig 13·18). elapsed for the cement to complete the setting reac
When inserting the restoration, the clinician must tions. During this examination, the patient executes
use a foward-and-backward movement while exert· closure as well as protrusive and lateral excursive
ing signiicant continuous pressure. The clinician pro movements while the clinician checks for premature
ceeds in this way to give the cement an escape route contacts or interferences. .
and because the crown must be seated with the
. . . '
1 3· 2 0
igs 1 3� 13 to 13-16 Placement of excess cement inside the crown often stems from a fear of not applying a sufficient amount. ment. without exceeding the limit. t o allow air t o escape a n d t o spread the cement over the internal portion o f the restoration
whiCh 1s a rare occurrence. Figs 13-13 and 13-14 Excess cement before and after seating of the restoration on an extracted and along the preparation walls. Fig 13-18 After adapting and checking the correct seating. the operating field is isolated with
tooth. Fig 13-15 Reduced cement application. only in the internal portion. Fig 13-16 Optimum cementation after adaptation is tinfoil. and a piece of soft balsa wood is positioned between the crown and the antagonist teeth. Figs 13-1 g and 13-20 After
confirmed by minimal excess and beads of cement at the margin ion an extracted tooth). Fig 13-17 Retraction cord of the cementation with zinc phosphate. excess cement forms small beads rather than a consistent line around the entire margin
smallest diameter possible is Inserted to maintain margin accessibility. Ideal cement application on the tooth preparation circumference Bead formation indicates that cementation has occurred and that there is close contact between the metal and
should be equivalent to the die spacer. When adapting the crown. the clinician should exert a forward-and- backward move· the underlying prepared tooth.
415
Cementation
·- -
1 3-23
set. This should be perform ed under water spray.

Figs 13-21 and 13-22 Close adaptation o f ceramic crown and nalural looth. The small glass-ionomer beads are removed using a scaler. Fig 13-25 Remova l of retractio n cord after cement has material remainin g in the gin
g the retractio n cord tends to take off residual cement the clinician will have to remove any
fig 1 3-23 Optimum contact between lhe framework and the restoration margin after cementation of a ceramic restoration with a zirconia core F1g 13-26 Removin
gival sulcus using a sharp explore r or scaler.
(lava).
Fig 1 3-24 Cementation with a glass-ionomer cement. which is spread minimally over the prepared tooth.
417
416
Cementation
·- -
1 3-23
set. This should be perform ed under water spray.

Figs 13-21 and 13-22 Close adaptation o f ceramic crown and nalural looth. The small glass-ionomer beads are removed using a scaler. Fig 13-25 Remova l of retractio n cord after cement has material remainin g in the gin
g the retractio n cord tends to take off residual cement the clinician will have to remove any
fig 1 3-23 Optimum contact between lhe framework and the restoration margin after cementation of a ceramic restoration with a zirconia core F1g 13-26 Removin
gival sulcus using a sharp explore r or scaler.
(lava).
Fig 1 3-24 Cementation with a glass-ionomer cement. which is spread minimally over the prepared tooth.
417
416
CHAPTER T J
-- -
e m entation
.. D I STI N CTIVE FEURES raised with a spatula once mixing has been com . moved and until the setting reaction is completed Adhesive res in cements
OF CEMENTS pleted, but a consistent ilament must not be formed. and the gel matrix has formed. (The cement will
For this material, an ideal consistency has been have a rubbey appearance. 28·29) The clinician can Protocol for silica-based
Zinc phosphate cements reached when the material mass falls back on itself. protect the restoration margin using isolating lac· and translucent restorations
quers, such as protective sealants (Ketac Glaze, 3M The broad range of adhesive resin cements that are
The setting reaction of zinc phosphates is exother ESPE or Fuji Coat LC. GO. or special aluminum sheets. available precludes a protocol that is common to all
Glass-ionomer cem ents
mic, and heat is already released by the time the The lacquers are not removed by the clinician but types of adhesive cementation. In the authors' opin
mixing phase begins. Therefore, mixing must be ac Polyacylic acid is applied to the prepared tooth for will be eliminated in the following days during the ion, adhesive techniques are advantageous for trans
complished by gradually incorporating small quan 30 seconds to produce mild etching and prepare the course of normal oral hygiene. lucent restorations that lend themselves to etching
tities of powder into the liquid to enable the heat ionic surface mobility. 24-2S After rinsing with a spray, procedures and can exploit advantages ofered by
to disperse progressively. Additionally, the clinician the tooth must be dried but not dehydrated. Dying composites (eg, good esthetis, low solubility in luids.
Res i n - reinforced glass-ionomer
should spatulate the cement accurately over a broad must be carried out simply by positioning the tip of hardening with the ceramic material. photopolymeri
cements
s u rface. The use of a plate cooled continuously by the extractor air jet close to the preparations to zation). In general. however. this adhesive cementa
a special electric mechanism (Cooltron, Dentro) (Fig remove excess liquid. A direct air jet should not be These cements are derivatives of glass ionomers. and tion cannot be used with metal-free, non-silica-based
13-27) or pre-cooled to a temperature of 6°C to used. When dried, the tooth surface should have a their processing, mixing, and consistency are simi materials, eg. zirconia- and alumina-based materials.
-10•c can also help ofset the heat generated during shiny appearance but should not be noticeably wet lar to those materials. The procedures described for The adhesive cementation technique for translucent
mixing. Compared with using a plate at room tem or dry. 26, 27 glass-ionomer materials also apply to these cements. restorations, which difers greatly from the protocols
perature, the cooled plate enables a much higher Glass-ionomer cements are available in a powder The mixing time is usually close to 30 seconds, examined previously, is summarized below.
volume of powder to be incorporated, and this ex liquid form to be mixed manually or in capsules to and setting generally requires 2.5 minutes. However,
tends the processing time when cementing large be mixed mechanically. Cements that are mixed the setting time can be increased by using special Adhesive cementation
restorations while maintaining the mechanical prop manually should be handled on a rigid glass plate cements (Fuji Plus EWT. GC) that enable bonding of of translucent restorations
erties of the cement 23 (not cooled). The powder is divided into two equal extensive restorations without running the risk of Restorations executed entirely with ceramic materi
The luid cement can be applied once the mixture portions. The first portion must be incorporated into the cement stating to set before the restoration has als include complete crowns, anterior veneers, and
has attained the appropriate consistency. This can the liquid and mixed immediately. The remaining been positioned completely. posterior inlays. The latter type of restoration is not
be veriied by raising the spatula 2 or 3 em above portion follows with spatulation, which must be per Some dual-paste cements are packaged with a me covered in this text, and while the rationale for
the plate and checking for the formation of a con formed again using a rigid instrument for 30 to 6o chanical dosage instrument, but these can also be these cementation procedures can be adapted to
tinuous cement ilament between the mixing surface seconds until the material mass falls back on itself. mixed manually (as in the case of FujiCem. which ceramic inlays, only phases specific to crowns and
and the steel spatula (Fig 13-28). Correct spatulation Products supplied in capsules must be activated by has a shorter mixing time than powder-liquid ce anterior veneers will be described.
must be completed within 6o to 90 seconds; this breaking the membrane that separates the two com ments). Manual mixing prevents the incorporation of
time can be extended i f a cooled plate is used. The air during the mixing phase. Removing the provisional estoraion
ponents inside the capsules. The components a re
amount of time for setting will vay depending on Although sensitivity to moisture is less evident in and provisional cement
then vibrated in a mechanical mixer and inserted
the product, although the reaction time is generally these cements. the clinician should protect the ex s discussed previously. residue of provisional ce
into a special applicator.
between 2.5 and 8 minutes. posed cement with protective sealants or special alu ment must be carefully removed to ensure that
Because of the material's high sensitivity to mois
minum sheets, just as for traditional glass ionomers. efective deinitive adhesion can be achieved. The
ture during setting, the clinician should leave any
In theory, contact between sot tissues and the un prepared tooth is cleaned with hand instruments,
Zinc polycarboxylate cements excess cement close to the restoration margin to
polymerized cement also should be minimized be using brushes with pumice or fluoride-free prophy
protect the material against contamination by oral
These cements must have a creamy consistency, denser cause of the presence of 2-hydroxyethylmethacylate laxis paste (Figs 13-29 to 13-31), or with airborne
fluids. Evey effort must be made to maintain a dry
than zinc phosphate cements. The material can be (HEMA), which is an acknowledged contact allergen)• particle abrasion. The prepared tooth can be washed ..
environment after the excess cement has been re- ..
41!
411
CHAPTER T J
-- -
e m entation
.. D I STI N CTIVE FEURES raised with a spatula once mixing has been com . moved and until the setting reaction is completed Adhesive res in cements
OF CEMENTS pleted, but a consistent ilament must not be formed. and the gel matrix has formed. (The cement will
For this material, an ideal consistency has been have a rubbey appearance. 28·29) The clinician can Protocol for silica-based
Zinc phosphate cements reached when the material mass falls back on itself. protect the restoration margin using isolating lac· and translucent restorations
quers, such as protective sealants (Ketac Glaze, 3M The broad range of adhesive resin cements that are
The setting reaction of zinc phosphates is exother ESPE or Fuji Coat LC. GO. or special aluminum sheets. available precludes a protocol that is common to all
Glass-ionomer cem ents
mic, and heat is already released by the time the The lacquers are not removed by the clinician but types of adhesive cementation. In the authors' opin
mixing phase begins. Therefore, mixing must be ac Polyacylic acid is applied to the prepared tooth for will be eliminated in the following days during the ion, adhesive techniques are advantageous for trans
complished by gradually incorporating small quan 30 seconds to produce mild etching and prepare the course of normal oral hygiene. lucent restorations that lend themselves to etching
tities of powder into the liquid to enable the heat ionic surface mobility. 24-2S After rinsing with a spray, procedures and can exploit advantages ofered by
to disperse progressively. Additionally, the clinician the tooth must be dried but not dehydrated. Dying composites (eg, good esthetis, low solubility in luids.
Res i n - reinforced glass-ionomer
should spatulate the cement accurately over a broad must be carried out simply by positioning the tip of hardening with the ceramic material. photopolymeri
cements
s u rface. The use of a plate cooled continuously by the extractor air jet close to the preparations to zation). In general. however. this adhesive cementa
a special electric mechanism (Cooltron, Dentro) (Fig remove excess liquid. A direct air jet should not be These cements are derivatives of glass ionomers. and tion cannot be used with metal-free, non-silica-based
13-27) or pre-cooled to a temperature of 6°C to used. When dried, the tooth surface should have a their processing, mixing, and consistency are simi materials, eg. zirconia- and alumina-based materials.
-10•c can also help ofset the heat generated during shiny appearance but should not be noticeably wet lar to those materials. The procedures described for The adhesive cementation technique for translucent
mixing. Compared with using a plate at room tem or dry. 26, 27 glass-ionomer materials also apply to these cements. restorations, which difers greatly from the protocols
perature, the cooled plate enables a much higher Glass-ionomer cements are available in a powder The mixing time is usually close to 30 seconds, examined previously, is summarized below.
volume of powder to be incorporated, and this ex liquid form to be mixed manually or in capsules to and setting generally requires 2.5 minutes. However,
tends the processing time when cementing large be mixed mechanically. Cements that are mixed the setting time can be increased by using special Adhesive cementation
restorations while maintaining the mechanical prop manually should be handled on a rigid glass plate cements (Fuji Plus EWT. GC) that enable bonding of of translucent restorations
erties of the cement 23 (not cooled). The powder is divided into two equal extensive restorations without running the risk of Restorations executed entirely with ceramic materi
The luid cement can be applied once the mixture portions. The first portion must be incorporated into the cement stating to set before the restoration has als include complete crowns, anterior veneers, and
has attained the appropriate consistency. This can the liquid and mixed immediately. The remaining been positioned completely. posterior inlays. The latter type of restoration is not
be veriied by raising the spatula 2 or 3 em above portion follows with spatulation, which must be per Some dual-paste cements are packaged with a me covered in this text, and while the rationale for
the plate and checking for the formation of a con formed again using a rigid instrument for 30 to 6o chanical dosage instrument, but these can also be these cementation procedures can be adapted to
tinuous cement ilament between the mixing surface seconds until the material mass falls back on itself. mixed manually (as in the case of FujiCem. which ceramic inlays, only phases specific to crowns and
and the steel spatula (Fig 13-28). Correct spatulation Products supplied in capsules must be activated by has a shorter mixing time than powder-liquid ce anterior veneers will be described.
must be completed within 6o to 90 seconds; this breaking the membrane that separates the two com ments). Manual mixing prevents the incorporation of
time can be extended i f a cooled plate is used. The air during the mixing phase. Removing the provisional estoraion
ponents inside the capsules. The components a re
amount of time for setting will vay depending on Although sensitivity to moisture is less evident in and provisional cement
then vibrated in a mechanical mixer and inserted
the product, although the reaction time is generally these cements. the clinician should protect the ex s discussed previously. residue of provisional ce
into a special applicator.
between 2.5 and 8 minutes. posed cement with protective sealants or special alu ment must be carefully removed to ensure that
Because of the material's high sensitivity to mois
minum sheets, just as for traditional glass ionomers. efective deinitive adhesion can be achieved. The
ture during setting, the clinician should leave any
In theory, contact between sot tissues and the un prepared tooth is cleaned with hand instruments,
Zinc polycarboxylate cements excess cement close to the restoration margin to
polymerized cement also should be minimized be using brushes with pumice or fluoride-free prophy
protect the material against contamination by oral
These cements must have a creamy consistency, denser cause of the presence of 2-hydroxyethylmethacylate laxis paste (Figs 13-29 to 13-31), or with airborne
fluids. Evey effort must be made to maintain a dry
than zinc phosphate cements. The material can be (HEMA), which is an acknowledged contact allergen)• particle abrasion. The prepared tooth can be washed ..
environment after the excess cement has been re- ..
41!
411
CHAPTER 1 3
--
Cementation
FIG 13-29
Fig 13-27 Cooled plate used to mix zinc phosphate cement. Fig 13-28 Correct viscosity of a ztnc phosphate cement indi cated by
a thread-like strand between the spatula and the plate. Fig 13-2g Prosthetic preparation after removal of provisional restora·
tion and during the initial phase of an adhesive technique for a feldspathic ceramic crown. Figs 13-30 and 13-31 Cleaning of
the tooth preparation with a fluoride-free prophylaxis paste to remove surface contamination that may b e present.
. with cotton soaked in ethyl alcohol or, if provision restoration, the internal surface is contaminated by
al cement containing eugenol has been used, the contact, and the restoration must be sterilized to
tooth preparation can be mildly etched with ortho optimize adhesion to the bonding cements.
phosphoric acid to counter eugenol's negative efect
on adhesive strength. (Use of eugenol-containing Preparing the restoration for adhesion
cements is not recommended if adhesive resin ce The clinician should prepare a support to assist in
mentation is planned.) However, etching will be exe holding the restoration during preparation, especial
cuted during the preparatory phases for adhesion. ly when a porcelain laminate veneer is involved. A
The clinician also may use a medium-grit diamond small quantity of soft wax can be affixed to the buc
bur to roughen the surface when removing a small cal surface of the restoration. The tip of an amalgam FIG 13-31
amount of luid resin used to provisionally bond the condenser inserted into the wax or an adhesive tip
veneers. of a flexible instrument (VivaStick, lvoclar Vivadent
or Pic-N-Stic, Pulpdent) can be used to facilitate ma
Esthetic chroma test nipulation of the restoration.
The esthetic test is useful, but postcementation The ceramic material can be conditioned using
chromatic changes can result from the use of pig etching, airborne-particle abrasion, or silanization,
mented composites or dual-polymerized cements that or by a combination of these methods.J' Before acid
contain amines. These materials should be avoided etching the internal surface of a restoration, the
since color change is u npredictable and cannot be clinician should apply a layer of laboratory wax (or
accurately anticipated. The authors prefer neutral plasticine-type modeling material) along the entire
cements that do not alter the chroma of the ceram exterior perimeter of the preparation to prevent con
ic material, and therefore use glycerine gel as the tact between the esthetic surface of the restoration
retentive element during the chromatic test. When and the conditioning products. An etching solution
an esthetic test is performed on an all-ceramic of 10% hydrofluoric acid is applied for 90 seconds • ..
FIG 13-31
0
CHAPTER 1 3
--
Cementation
FIG 13-29
Fig 13-27 Cooled plate used to mix zinc phosphate cement. Fig 13-28 Correct viscosity of a ztnc phosphate cement indi cated by
a thread-like strand between the spatula and the plate. Fig 13-2g Prosthetic preparation after removal of provisional restora·
tion and during the initial phase of an adhesive technique for a feldspathic ceramic crown. Figs 13-30 and 13-31 Cleaning of
the tooth preparation with a fluoride-free prophylaxis paste to remove surface contamination that may b e present.
. with cotton soaked in ethyl alcohol or, if provision restoration, the internal surface is contaminated by
al cement containing eugenol has been used, the contact, and the restoration must be sterilized to
tooth preparation can be mildly etched with ortho optimize adhesion to the bonding cements.
phosphoric acid to counter eugenol's negative efect
on adhesive strength. (Use of eugenol-containing Preparing the restoration for adhesion
cements is not recommended if adhesive resin ce The clinician should prepare a support to assist in
mentation is planned.) However, etching will be exe holding the restoration during preparation, especial
cuted during the preparatory phases for adhesion. ly when a porcelain laminate veneer is involved. A
The clinician also may use a medium-grit diamond small quantity of soft wax can be affixed to the buc
bur to roughen the surface when removing a small cal surface of the restoration. The tip of an amalgam FIG 13-31
amount of luid resin used to provisionally bond the condenser inserted into the wax or an adhesive tip
veneers. of a flexible instrument (VivaStick, lvoclar Vivadent
or Pic-N-Stic, Pulpdent) can be used to facilitate ma
Esthetic chroma test nipulation of the restoration.
The esthetic test is useful, but postcementation The ceramic material can be conditioned using
chromatic changes can result from the use of pig etching, airborne-particle abrasion, or silanization,
mented composites or dual-polymerized cements that or by a combination of these methods.J' Before acid
contain amines. These materials should be avoided etching the internal surface of a restoration, the
since color change is u npredictable and cannot be clinician should apply a layer of laboratory wax (or
accurately anticipated. The authors prefer neutral plasticine-type modeling material) along the entire
cements that do not alter the chroma of the ceram exterior perimeter of the preparation to prevent con
ic material, and therefore use glycerine gel as the tact between the esthetic surface of the restoration
retentive element during the chromatic test. When and the conditioning products. An etching solution
an esthetic test is performed on an all-ceramic of 10% hydrofluoric acid is applied for 90 seconds • ..
FIG 13-31
0
. then nnsed with abundant quantitieS of water and menta JOn appointment or after tooth preparation . Cement application and seaing of the restoration activation. All e\Cess cement must be remo ed at this
dned wilh a strong a1r 1e1 (Fig 13-32). The restoration and before the impression is taken (dual-bonding s prev1ously noted. the authors prefer a cementa· stage. smce 11 IS diicult to remove ater complete!
is immersed in a 95% alcohol solution and exposed techn•que)." J6- J7 The second option JS preferable; tion process activated exclusively by light for translu· sening.
to ultrasonic vibration for 5 minutes" to remove the the hybrid layer begins with acid etchmg, then primer cent restorations. The cement normally used for thiS
ceramic salts on the internal surface, which could application, and finally adhesive resin applicat•on purpose is represented by m1crohybrid composites. olymerization
reduce the bondmg strength of the cement. and polymenzation. such as Herculite XRV, Filtek Z250 (3M ESPEl, and The adhesl'e resin cement is polymerized using var·
At this point. silane is appliedll in accordance w1th Tetric Ceram (lvoclar Vivadent). Bonding products, •ous lamps: halogen, plasma, arc-•enon. and light·
the manufacture�s mstruct1ons (ig 13·33), using a Adhesion to the prepared toth and the restoration such as RelyX Veneer Cement and Variolink II. com· em•nmg diode. The wavelength needed to initiate
dual-component (Ciearil, Kuraray) or single-component The adhesion procedure begins after the operatmg bine a base paste with a chemical catalyst and a the polymerization process ranges bet'een 40 and
material (Silane, Ultradent or Monobond-5. Jvoclar ield has been isolated and cemenl residue has been speciic light source for polymerization. The cement 50 nm. The required enegy is at least 50 mW/cm'.
Vivadent). removed. An etching solution of 35% to 37% phos· used in this type of procedure is a paste. wh1ch can although high-energy lamps designed speciically for
The clinician must remove moisture from the cer· phoric acid •s applied for at least 30 seconds. and be manipulated with a spatula. If the clinician IS not polymerization exceed 1.00 mWtcm'. Photopol ·
amic and dry the silane,4-ll either by placing the the area is rinsed with abundant quantities of water sat1sfied with the composite's viscosity, the product merization must occur on each surface of the res·
restoration in a o•c oven for 6o seconds or direct· (without spray) (Figs 13·40 to 13·42). If the dentin container can be heated slightly by holding il tight· toration for an extended period. If the restoration
ing a jet of hot air from a hair dyer at the condi· requires hybridization. the primer is applied on ly between the hands for a few minutes, by using a involves veneers. the clinician should begm on the
tioned area (Fig 13-34). moist dentin; if this has already been executed. the thermostatic pan, or by placing the container in a palatal side, to polymerize the adhesive cement
procedure continues with the adhesive phase (Figs special heater (Calset, AdDent). Because dual poly· toward the natural dental structure. Results of the
Isolating the operating ield 13-43 and 13-44). merization is not well suited for translucent restora· various lighting technologies vary l (Fig 13·50).
For micromechani!l adhesion, the clinician must close· tions. the base paste can be used alone. followed by The surface composite that comes into contact
The bonding phase is implemented for the rec·
ly monitor the mo1sture around the adhesion site. photopolymerization. with the oxygen does not polymerize completely,
ommended amount of time. Direct lighting from the
Rubber dam provides the best isolation of the oper· The restoration is carefully positioned on the pre· and for this reason a transparent glycerine gel is
operating lamp should be blocked to prevent pre·
pared site, and pressure is gradually increased to used.J9 This gel prevents contact with the o ygen
ating ield (Figs 13-35 to 13-39). If the use of rubber mature polymerization and redirected only after the
allow excess cement to escape. The restoration is and ensures further polymerization. Ater polymer·
dam is not possible, a small retraction cord can be photopolymerization of the cement has begun. A
then fully seated. either manually or using an ultra· ization is completed. rubber dam, retraction cords,
positioned in the sulcus, and photopolymerizing bar· brush or sponge is used to spread the adhesive
sonic instrument that has a Telon-covered tip. and other isolation aids aln be removed.
riers aln be used. resin uniformly over the entire prepared tooth and
on the internal surface of the restoration. However,
inishing and poUshing
Enamel-dentin hybrid layers most clinicians prefer to use the resin-bonding ce· Removing excess cement
Excess cement must be removed while the restora· Excess adhesive material at the cervical margin is
Dental enamel is the optimum substrate for adhesive men! (Herculite FL for veneers and Herculite XRV
tion is held in position with a hand instrument or removed with a no. 12 cuved blade itted to a scalpel
cementation; however, it is common to find extend· Medium for crowns, Kerr Hawe) on the interior sur·
directly with the ingers of one hand. Cement re· (Figs 13-51 and 13·52). The restoration and the cemen·
ed dentin sites on the prepared tooth. The enamel· face of the restoration (Figs 13-45 and 13·46). The
moval can be accomplished using explores. sponges. tation site are inished using rubber tips of decreas·
dentin adhesive system is used for this type of resin-bonding cement is very fluid at this stage from
waxed floss, or a sponge-covered loss (Superloss. ing hardness. abrasive disks, and abrasive interproxi·
cementation to protect against thermal shocks and contact with modest heat (about 40•0. If the adhe·
Oral B) (Figs 13-47 to 13·49). These procedures must mal strips. Polishing is completed using brushes.
bacterial contamination, which impact the pulp cham· sive resin is prepolymerized before the resin-bonding
be performed carefully to avoid irritating the sur· felts. and tips containing polishing substances••·••
ber. A hybrid layer is formed between the collagen cement, undesired bonding thicknesses may occur.
rounding tissues and to prevent contamination before (Figs 13-53 to 13·59). ..
fiber matrix on the exposed dentinal surface and the A multicomponent adhesive system can manage
adhesive resin to create a protective barrier. Dentin each adhesion phase specifically (Scotchbond MP,
hybridization can be accomplished during the ce· 3M ESPE or Optibond FL. Kerr Hawe). .
23
22
. then nnsed with abundant quantitieS of water and menta JOn appointment or after tooth preparation . Cement application and seaing of the restoration activation. All e\Cess cement must be remo ed at this
dned wilh a strong a1r 1e1 (Fig 13-32). The restoration and before the impression is taken (dual-bonding s prev1ously noted. the authors prefer a cementa· stage. smce 11 IS diicult to remove ater complete!
is immersed in a 95% alcohol solution and exposed techn•que)." J6- J7 The second option JS preferable; tion process activated exclusively by light for translu· sening.
to ultrasonic vibration for 5 minutes" to remove the the hybrid layer begins with acid etchmg, then primer cent restorations. The cement normally used for thiS
ceramic salts on the internal surface, which could application, and finally adhesive resin applicat•on purpose is represented by m1crohybrid composites. olymerization
reduce the bondmg strength of the cement. and polymenzation. such as Herculite XRV, Filtek Z250 (3M ESPEl, and The adhesl'e resin cement is polymerized using var·
At this point. silane is appliedll in accordance w1th Tetric Ceram (lvoclar Vivadent). Bonding products, •ous lamps: halogen, plasma, arc-•enon. and light·
the manufacture�s mstruct1ons (ig 13·33), using a Adhesion to the prepared toth and the restoration such as RelyX Veneer Cement and Variolink II. com· em•nmg diode. The wavelength needed to initiate
dual-component (Ciearil, Kuraray) or single-component The adhesion procedure begins after the operatmg bine a base paste with a chemical catalyst and a the polymerization process ranges bet'een 40 and
material (Silane, Ultradent or Monobond-5. Jvoclar ield has been isolated and cemenl residue has been speciic light source for polymerization. The cement 50 nm. The required enegy is at least 50 mW/cm'.
Vivadent). removed. An etching solution of 35% to 37% phos· used in this type of procedure is a paste. wh1ch can although high-energy lamps designed speciically for
The clinician must remove moisture from the cer· phoric acid •s applied for at least 30 seconds. and be manipulated with a spatula. If the clinician IS not polymerization exceed 1.00 mWtcm'. Photopol ·
amic and dry the silane,4-ll either by placing the the area is rinsed with abundant quantities of water sat1sfied with the composite's viscosity, the product merization must occur on each surface of the res·
restoration in a o•c oven for 6o seconds or direct· (without spray) (Figs 13·40 to 13·42). If the dentin container can be heated slightly by holding il tight· toration for an extended period. If the restoration
ing a jet of hot air from a hair dyer at the condi· requires hybridization. the primer is applied on ly between the hands for a few minutes, by using a involves veneers. the clinician should begm on the
tioned area (Fig 13-34). moist dentin; if this has already been executed. the thermostatic pan, or by placing the container in a palatal side, to polymerize the adhesive cement
procedure continues with the adhesive phase (Figs special heater (Calset, AdDent). Because dual poly· toward the natural dental structure. Results of the
Isolating the operating ield 13-43 and 13-44). merization is not well suited for translucent restora· various lighting technologies vary l (Fig 13·50).
For micromechani!l adhesion, the clinician must close· tions. the base paste can be used alone. followed by The surface composite that comes into contact
The bonding phase is implemented for the rec·
ly monitor the mo1sture around the adhesion site. photopolymerization. with the oxygen does not polymerize completely,
ommended amount of time. Direct lighting from the
Rubber dam provides the best isolation of the oper· The restoration is carefully positioned on the pre· and for this reason a transparent glycerine gel is
operating lamp should be blocked to prevent pre·
pared site, and pressure is gradually increased to used.J9 This gel prevents contact with the o ygen
ating ield (Figs 13-35 to 13-39). If the use of rubber mature polymerization and redirected only after the
allow excess cement to escape. The restoration is and ensures further polymerization. Ater polymer·
dam is not possible, a small retraction cord can be photopolymerization of the cement has begun. A
then fully seated. either manually or using an ultra· ization is completed. rubber dam, retraction cords,
positioned in the sulcus, and photopolymerizing bar· brush or sponge is used to spread the adhesive
sonic instrument that has a Telon-covered tip. and other isolation aids aln be removed.
riers aln be used. resin uniformly over the entire prepared tooth and
on the internal surface of the restoration. However,
inishing and poUshing
Enamel-dentin hybrid layers most clinicians prefer to use the resin-bonding ce· Removing excess cement
Excess cement must be removed while the restora· Excess adhesive material at the cervical margin is
Dental enamel is the optimum substrate for adhesive men! (Herculite FL for veneers and Herculite XRV
tion is held in position with a hand instrument or removed with a no. 12 cuved blade itted to a scalpel
cementation; however, it is common to find extend· Medium for crowns, Kerr Hawe) on the interior sur·
directly with the ingers of one hand. Cement re· (Figs 13-51 and 13·52). The restoration and the cemen·
ed dentin sites on the prepared tooth. The enamel· face of the restoration (Figs 13-45 and 13·46). The
moval can be accomplished using explores. sponges. tation site are inished using rubber tips of decreas·
dentin adhesive system is used for this type of resin-bonding cement is very fluid at this stage from
waxed floss, or a sponge-covered loss (Superloss. ing hardness. abrasive disks, and abrasive interproxi·
cementation to protect against thermal shocks and contact with modest heat (about 40•0. If the adhe·
Oral B) (Figs 13-47 to 13·49). These procedures must mal strips. Polishing is completed using brushes.
bacterial contamination, which impact the pulp cham· sive resin is prepolymerized before the resin-bonding
be performed carefully to avoid irritating the sur· felts. and tips containing polishing substances••·••
ber. A hybrid layer is formed between the collagen cement, undesired bonding thicknesses may occur.
rounding tissues and to prevent contamination before (Figs 13-53 to 13·59). ..
fiber matrix on the exposed dentinal surface and the A multicomponent adhesive system can manage
adhesive resin to create a protective barrier. Dentin each adhesion phase specifically (Scotchbond MP,
hybridization can be accomplished during the ce· 3M ESPE or Optibond FL. Kerr Hawe). .
23
22
Cementation
3-39
Figs 13-32 o 13-4 Treatment of the feldspalhic ceramic crown after lry-in.
_ The authors prefer to etch and silanize in the dental office after Figs 13-35 to 13-3g Rubber dam i n place t o prevent contamination during bond1ng phase o f complete crowns.
try-1n. rather than to rece1ve the restoration from the laboratory already
treated.
Fig 13-32 After the externa l surface is isolated. the internal surface is Fig 13-35 Isolation from premolar to premolar with rubber dam secured with a ho � k (no. 2 1 2. Ivory) on the right central incisor. allowing
_ a water etched with a 1 0% hydrofluori c acid solution for g o seconds and access to the finish line (a modified chamfer). Fig 13-36 Etch1ng of the nght central InCisor w1th 37% orthophosphonc ac1d. The adJacent teeth
then washed abundantly w1th Jet for g o se conds. After etchin � . the ceramic salts. which could contaminate
mise the cementahon . should b e removed by plac1ng . the surface and compro are protected using a matrix. and a nearby prepared tooth is covered w1th a Teflon sheet during bonding to av01d interhr ! ng with the subse
the restoratiOn 1n a g 5% alcohol solution exposed to ultrasonic vibration quent bonding. Fig 13-37 Seating of the central incisor restoratiOn by uerllng slight. conllnuous . pr! ssu �e. Excess cement IS removed accord
Fig 13-33 Appllcallon of Silane w1th a brush. Fig 13-4 Silane must be dried completely for 5 minutes.
with a hot-air hair dryer. _
ing to technique (see Fig 1 3 -221. Fig 13-38 After cementation of the central InCISor. the lateral lnmor IS ISolated .w1th the no. 2 1 2 hook The
authors prefer to cement restorations one by one when several restoratiOns are to b e bonded USing the adheme technique: the bondmg
g
phases are repeated for each tooth. Fig 13-3 Two feldspathic ceramiC crowns.
Cementation
3-39
Figs 13-32 o 13-4 Treatment of the feldspalhic ceramic crown after lry-in.
_ The authors prefer to etch and silanize in the dental office after Figs 13-35 to 13-3g Rubber dam i n place t o prevent contamination during bond1ng phase o f complete crowns.
try-1n. rather than to rece1ve the restoration from the laboratory already
treated.
Fig 13-32 After the externa l surface is isolated. the internal surface is Fig 13-35 Isolation from premolar to premolar with rubber dam secured with a ho � k (no. 2 1 2. Ivory) on the right central incisor. allowing
_ a water etched with a 1 0% hydrofluori c acid solution for g o seconds and access to the finish line (a modified chamfer). Fig 13-36 Etch1ng of the nght central InCisor w1th 37% orthophosphonc ac1d. The adJacent teeth
then washed abundantly w1th Jet for g o se conds. After etchin � . the ceramic salts. which could contaminate
mise the cementahon . should b e removed by plac1ng . the surface and compro are protected using a matrix. and a nearby prepared tooth is covered w1th a Teflon sheet during bonding to av01d interhr ! ng with the subse
the restoratiOn 1n a g 5% alcohol solution exposed to ultrasonic vibration quent bonding. Fig 13-37 Seating of the central incisor restoratiOn by uerllng slight. conllnuous . pr! ssu �e. Excess cement IS removed accord
Fig 13-33 Appllcallon of Silane w1th a brush. Fig 13-4 Silane must be dried completely for 5 minutes.
with a hot-air hair dryer. _
ing to technique (see Fig 1 3 -221. Fig 13-38 After cementation of the central InCISor. the lateral lnmor IS ISolated .w1th the no. 2 1 2 hook The
authors prefer to cement restorations one by one when several restoratiOns are to b e bonded USing the adheme technique: the bondmg
g
phases are repeated for each tooth. Fig 13-3 Two feldspathic ceramiC crowns.
·�.---,
Cementation
L . , '" '
;
XR '/HERc�e
Figs 13-l When placement of rubber dam IS Impossible. the smallest possible retraction cord can be inserted to access
the finish line. check Fig 13-46 Application of the resin cement directly inside the restoration. after application of the bonding res1n without photopoly��r�zation.
the adaptation. and prevent Interference w1th the g1ngival tissue. Removal of the retraction cord may also help · _
to eliminate residue of poly Fig 13 -47 Excess compos1·1 e reSin mu st be removed before photopolymerization·· the crown IS kept 1n place by pressure from the cliniCian. who
merized cement that has not adhered to dental tissues. .
eliminates the excess interproximal cement w1th floss.
F1gs 1 3-41 and 13-42 Etch1ng With 37% orthophosphoric acid for 20 seconds. since the substrate consists of dentin and
composite. The etched Fig 13-48 Excess cement in the buccal and palatal areas is removed with a microbrush soaked in fluid resin
surface must be thoroughly washed w1th water to remove the acid.
Figs 1 3-43 and 13-4 Primer is applied as a dentin conditioner in controlled moisture cond1t1ons. Some primers must Fig 13-49 Any remaining excess cement is removed before photopolymerization with a sharp explorer. moved along the tooth IXIS
be dried after 30 seconds .
with a soli a1r jet rather than photopolymeme d A th1n layer of bonding res1n IS then spread over the tooth preparation Fig 1 3-50 Photo p ol y merization from another case. For veneers. the palatal surface of the. tooth musl be positioned between the labial restora-
with a small brush. _ an d th e source o f 1 1g ht . F or complete crowns · the light must be d�rected at the vanous surfaces of the restoration for 2 m1nutes
Fig 1 3-45 Restorative resin compos1te IHercul1te XRV Incisal Med1um1 su1table for cementing translucent restorations. t1on
21
·�.---,
Cementation
L . , '" '
;
XR '/HERc�e
Figs 13-l When placement of rubber dam IS Impossible. the smallest possible retraction cord can be inserted to access
the finish line. check Fig 13-46 Application of the resin cement directly inside the restoration. after application of the bonding res1n without photopoly��r�zation.
the adaptation. and prevent Interference w1th the g1ngival tissue. Removal of the retraction cord may also help · _
to eliminate residue of poly Fig 13 -47 Excess compos1·1 e reSin mu st be removed before photopolymerization·· the crown IS kept 1n place by pressure from the cliniCian. who
merized cement that has not adhered to dental tissues. .
eliminates the excess interproximal cement w1th floss.
F1gs 1 3-41 and 13-42 Etch1ng With 37% orthophosphoric acid for 20 seconds. since the substrate consists of dentin and
composite. The etched Fig 13-48 Excess cement in the buccal and palatal areas is removed with a microbrush soaked in fluid resin
surface must be thoroughly washed w1th water to remove the acid.
Figs 1 3-43 and 13-4 Primer is applied as a dentin conditioner in controlled moisture cond1t1ons. Some primers must Fig 13-49 Any remaining excess cement is removed before photopolymerization with a sharp explorer. moved along the tooth IXIS
be dried after 30 seconds .
with a soli a1r jet rather than photopolymeme d A th1n layer of bonding res1n IS then spread over the tooth preparation Fig 1 3-50 Photo p ol y merization from another case. For veneers. the palatal surface of the. tooth musl be positioned between the labial restora-
with a small brush. _ an d th e source o f 1 1g ht . F or complete crowns · the light must be d�rected at the vanous surfaces of the restoration for 2 m1nutes
Fig 1 3-45 Restorative resin compos1te IHercul1te XRV Incisal Med1um1 su1table for cementing translucent restorations. t1on
21
Cementation
Fig 13-51 Once polymerization is complete. excess bonding cement and polymerized composite are removed using a no. 12 scalpel with a Figs 13-56 and 13-57 Definitive restorations in relation to the antagonist and adjacent teeth. The satisfactory integration of the veneers with the
curved blade gingival tissues confers a pleasing appearance. despite the fact that the cervical margins of the lateral incisors are more coronal than the
restorations.
Fig 13-52 Restoration is well integrated Immediately after cementation.
Figs 13-58and 13-5g Lateral view of the restorations seen through the stereomicroscope. and the frontal appearance of the papilla. Close adap
Fig 13-53 Clinical case of two teeth fractured 8 years previously as the result of a trauma. The composite restorations were inadequate. tation of the gingival tissue to the ceramic surface is allributed to the migration of the epithelial attachment.
Figs 13-4 and 13-55 Cementation is performed With rubber dam isolation. The precision of the adjacent restoration. which has already been
cemented. can be seen 1 n the 1nterprox1mal area shown under the stereom1croscope 1n F1g 1 3 -55.
Cementation
Fig 13-51 Once polymerization is complete. excess bonding cement and polymerized composite are removed using a no. 12 scalpel with a Figs 13-56 and 13-57 Definitive restorations in relation to the antagonist and adjacent teeth. The satisfactory integration of the veneers with the
curved blade gingival tissues confers a pleasing appearance. despite the fact that the cervical margins of the lateral incisors are more coronal than the
restorations.
Fig 13-52 Restoration is well integrated Immediately after cementation.
Figs 13-58and 13-5g Lateral view of the restorations seen through the stereomicroscope. and the frontal appearance of the papilla. Close adap
Fig 13-53 Clinical case of two teeth fractured 8 years previously as the result of a trauma. The composite restorations were inadequate. tation of the gingival tissue to the ceramic surface is allributed to the migration of the epithelial attachment.
Figs 13-4 and 13-55 Cementation is performed With rubber dam isolation. The precision of the adjacent restoration. which has already been
cemented. can be seen 1 n the 1nterprox1mal area shown under the stereom1croscope 1n F1g 1 3 -55.
· ---,
Cement
�----�
--
ation
�
- �
. Bondmg metal-free non-s1lica-based layer exposed at the margin and thus obtain com· . ment.- absence of a speciic chemical or mechanical mance aspects••·>' and othewise impro'e the solu·
restorations plete closure of the surface chains. Examples of adhesion to the dental substrate," and limited com· bility resistance in an aqueous environment in the
There are impotant differences between bonding materials used for this purpose are Panavia and pressive strength during seating." initial phases of setting.Jo.s• E en adhesion to tooth
translucent restorations and bonding non-silica-based RelyX ARC. Zinc polycaboxylate cement. in our opinion. allows and metals is improved over traditional glass iono·
restorations. Traditional metal-ceramic crowns or ce· Manufacturers are developing new autopolymer· for limited application in the permanent cementation mers,ll but the dental surace must be conditioned
ramie crowns with an aluminum or zirconium oxide izing adhesive cements (also with a light-curing com· of metal-ceramic prosthetic restorations but also has to optimize results.
core (Lava. 3M ESPE) have an opaque core that can ponent) with simpliied bonding procedures that fea· major drawbacks, namely high solubility2l·41 and Finally. resin composite or adhesive cements
be etched. One study42 evaluating the bonding ture the characteristics of current resin materials. poor mechanicophysical features. 46 have the potential to signiicantly change the con·
strength of cementation materials on zirconia has One of these new materials. RelyX Unicem (3M Glass-ionomer materials are well suited for use cept of cementation because they achieve a strong
shown that glass ionomers, resin-modiied glass ESPE), is mixed and hence chemically activated. This with porcelain·fused·to·metal prostheses. They bond to dental tissuesss .s• and to dierent dental
ionomers. and zinc phosphates have very low bond· product does not require a separate step to condi· achieve stable chemical adhesion with the dental materials,l'i9 a low solubility in a n aqueous envi·
ing values (near o MPa). whereas adhesive resin tion the surface because it prepares the dental sub· tissues4' and a number of metal alloys•8·•9 but ronment,o·6' and excellent performance under exter·
cements have bonding values ranging from 2.78 to Strate for adhesion independently at the time of also release tuoride,>0· 1 ' have reasonable mechanico· nal stresses.' 6
12.66 MPa, which is still considered low i n compar· cementation. Initial i n vitro data for this new cement physical features,>2 and do not require large com· Unfotunately. cementation techniques require ur·
ison with the values relative to ceramic surfaces. are encouraging. '8 pressive forces during seating." ther research to achieve predictable results, and
Although most of the cementation discussion for The most delicate aspect to be managed when indings are still limited.
translucent restorations is valid for restorations with using cement concerns its sensitivity to moisture in
CO N C L U S I O N S
opaque cores. polymerization can vary dramatically. the initial phase of the setting process, which . if
CASE PRESENTATI O N S
Polymerizing cements are classiied as either dual· Because no single permanent cement combines all neglected, can lead to dissolution of pat of the
polymerizing or auto polymerizing materials. When the of the ideal features needed for bonding, the choice cement. The authors strive to imitate natural function and
components (generally a composite base paste and between diferent types of cement must be made in Resin-modified glass·ionomer cements represent esthetics in clinical practice. Mimicking natural esthet·
a catalyst) are mixed, they initiate a chemical poly· relation to the restoration material (Table 13·1). another valid bonding cement that ofers many fea· ics and using the best restorative materials and
merization reaction before the cement is placed into Zinc phosphate materials are well tested and tures of traditional glass-ionomer cements,>0·>•·>3 techniques currently available ensures the oral health
the restoration. In general, the procedure involves used extensively.23·43 Compared with more recent with the exception that the former cements exhibit a of patients. Following are three case presentations
isolation of the surface oxygen with a glycerine gel cementation materials, this cement has a number of deterioration of mechanical stresses in some perfor· that demonstrate these ideals (Figs 13-60 to 13·91). •
to ensure final polymerization of the thin cement disadvantages. such as solubility in a moist environ· ..
31
· ---,
Cement
�----�
--
ation
�
- �
. Bondmg metal-free non-s1lica-based layer exposed at the margin and thus obtain com· . ment.- absence of a speciic chemical or mechanical mance aspects••·>' and othewise impro'e the solu·
restorations plete closure of the surface chains. Examples of adhesion to the dental substrate," and limited com· bility resistance in an aqueous environment in the
There are impotant differences between bonding materials used for this purpose are Panavia and pressive strength during seating." initial phases of setting.Jo.s• E en adhesion to tooth
translucent restorations and bonding non-silica-based RelyX ARC. Zinc polycaboxylate cement. in our opinion. allows and metals is improved over traditional glass iono·
restorations. Traditional metal-ceramic crowns or ce· Manufacturers are developing new autopolymer· for limited application in the permanent cementation mers,ll but the dental surace must be conditioned
ramie crowns with an aluminum or zirconium oxide izing adhesive cements (also with a light-curing com· of metal-ceramic prosthetic restorations but also has to optimize results.
core (Lava. 3M ESPE) have an opaque core that can ponent) with simpliied bonding procedures that fea· major drawbacks, namely high solubility2l·41 and Finally. resin composite or adhesive cements
be etched. One study42 evaluating the bonding ture the characteristics of current resin materials. poor mechanicophysical features. 46 have the potential to signiicantly change the con·
strength of cementation materials on zirconia has One of these new materials. RelyX Unicem (3M Glass-ionomer materials are well suited for use cept of cementation because they achieve a strong
shown that glass ionomers, resin-modiied glass ESPE), is mixed and hence chemically activated. This with porcelain·fused·to·metal prostheses. They bond to dental tissuesss .s• and to dierent dental
ionomers. and zinc phosphates have very low bond· product does not require a separate step to condi· achieve stable chemical adhesion with the dental materials,l'i9 a low solubility in a n aqueous envi·
ing values (near o MPa). whereas adhesive resin tion the surface because it prepares the dental sub· tissues4' and a number of metal alloys•8·•9 but ronment,o·6' and excellent performance under exter·
cements have bonding values ranging from 2.78 to Strate for adhesion independently at the time of also release tuoride,>0· 1 ' have reasonable mechanico· nal stresses.' 6
12.66 MPa, which is still considered low i n compar· cementation. Initial i n vitro data for this new cement physical features,>2 and do not require large com· Unfotunately. cementation techniques require ur·
ison with the values relative to ceramic surfaces. are encouraging. '8 pressive forces during seating." ther research to achieve predictable results, and
Although most of the cementation discussion for The most delicate aspect to be managed when indings are still limited.
translucent restorations is valid for restorations with using cement concerns its sensitivity to moisture in
CO N C L U S I O N S
opaque cores. polymerization can vary dramatically. the initial phase of the setting process, which . if
CASE PRESENTATI O N S
Polymerizing cements are classiied as either dual· Because no single permanent cement combines all neglected, can lead to dissolution of pat of the
polymerizing or auto polymerizing materials. When the of the ideal features needed for bonding, the choice cement. The authors strive to imitate natural function and
components (generally a composite base paste and between diferent types of cement must be made in Resin-modified glass·ionomer cements represent esthetics in clinical practice. Mimicking natural esthet·
a catalyst) are mixed, they initiate a chemical poly· relation to the restoration material (Table 13·1). another valid bonding cement that ofers many fea· ics and using the best restorative materials and
merization reaction before the cement is placed into Zinc phosphate materials are well tested and tures of traditional glass-ionomer cements,>0·>•·>3 techniques currently available ensures the oral health
the restoration. In general, the procedure involves used extensively.23·43 Compared with more recent with the exception that the former cements exhibit a of patients. Following are three case presentations
isolation of the surface oxygen with a glycerine gel cementation materials, this cement has a number of deterioration of mechanical stresses in some perfor· that demonstrate these ideals (Figs 13-60 to 13·91). •
to ensure final polymerization of the thin cement disadvantages. such as solubility in a moist environ· ..
31
.-
--�
� -
Cement
-:=. at
.Jion
--
TAB L E 1 3 - 1 Clinical i n dications for various cements and prosthetic restorations
Zinc Resin- Auto· Photo- Dual-

Zinc polycar- modified Nonadhesive polymerizing polymerizing polymerizing
Type of restoration phosphates boxylates ZOE GIC GIC resins adhesive resins adhesive resins adhesive resins
Metal-ceramic crowns ++ +/- -

+++
*
+++ +/- - - ++
with weak margins + +I- -

+ +++ +/- - -
+++
*
with ceramic micromargins +/- +/- -

+++
*
+++
*
+I- - - ++
- * - - - +++
with dentinal sensitivity + + +++ +++
- /- *
Feldspathic ceramic crowns or veneers - - - /
+ - +I- + +++ ++
I *
Cast ceramic or leucite crowns or veneers - - -
+/- +I- -
+ - +++ +
- - - * - I- - *
Ceramic crowns with alumina/zirconia core +++ +++ + +++
Non-noble alloy and ceramic resin-bonded *

- - - - +/- - /
+ - ++ +++
adhesive prosthesis
-
* - - - - -
Acrylic resin provisional crowns - + /-
++
-
* - - - - - -
permanent cementation without adhesive resin - + /- ++ (without
eugenol)
- * - - - ++
- +++ +++
Metal-ceramic crowns with AGC (Wieland) ++
or Captek (Precious Chemicals) systems

L
(ZOE) Zinc oxid�ugenol; (GI) glass-ionomer cement.
(-) Strongly discouraged; (/)
+ - not recommended; (+) possible; ( )
++ recommended; (
+++ ) strongly recommended.
()
* Used by the authors.
-
2
Cementation
1 3-67
Fig 1 3-60 Clinical case of a 40-year-old patient with macrodontia of the maxillary right central incisor and a direct composite restoration of figs 13-63 and 13-64 Analysis with a periodontal explorer that demonstrates the 1 3-mm length o f the clinical crown o n the right central incisor
congruent shape and color on the maxillary lefl central incisor following a previous trauma. The obvious esthetic compromise depended on following surgery. The new emergence profile enables a redistribution of space. Preparation of the lefl central incisor involves changing the
the anomalous width-height ratio of the teeth. The diagnostic waxup and periodontal crown lengthening treatment were designed to improve shape of the tooth to achieve improved proportion among the teeth.
the width-length ratio. Fig 13-65 Cementation of the provisional resin restoration following preparation of the four teeth for ceramic veneers.
Fig 13-61 Surgical lengthening of the clinical crown and changes via a delicate stripping procedure using diamond-studded inserts on an EVA Figs 1 3-66 o 13-6g Views of the original restoration and the four new feldspathic ceramic veneers after cementation.
type handpiece (61 LR head fitted on a 20 LH low-speed or on a 2 g LH reducer handpiece. Oentatus) and medium-grit metal strips. figs 1 3-70 and 13-71 Patient's smile before and after treatment. The porcelain laminate veneers show significant esthetic improvement in
Fig 13-62 Clinical results 6 months after periodontal crown lengthening. shape. color. and size ratio.
Cementation
1 3-67
Fig 1 3-60 Clinical case of a 40-year-old patient with macrodontia of the maxillary right central incisor and a direct composite restoration of figs 13-63 and 13-64 Analysis with a periodontal explorer that demonstrates the 1 3-mm length o f the clinical crown o n the right central incisor
congruent shape and color on the maxillary lefl central incisor following a previous trauma. The obvious esthetic compromise depended on following surgery. The new emergence profile enables a redistribution of space. Preparation of the lefl central incisor involves changing the
the anomalous width-height ratio of the teeth. The diagnostic waxup and periodontal crown lengthening treatment were designed to improve shape of the tooth to achieve improved proportion among the teeth.
the width-length ratio. Fig 13-65 Cementation of the provisional resin restoration following preparation of the four teeth for ceramic veneers.
Fig 13-61 Surgical lengthening of the clinical crown and changes via a delicate stripping procedure using diamond-studded inserts on an EVA Figs 1 3-66 o 13-6g Views of the original restoration and the four new feldspathic ceramic veneers after cementation.
type handpiece (61 LR head fitted on a 20 LH low-speed or on a 2 g LH reducer handpiece. Oentatus) and medium-grit metal strips. figs 1 3-70 and 13-71 Patient's smile before and after treatment. The porcelain laminate veneers show significant esthetic improvement in
Fig 13-62 Clinical results 6 months after periodontal crown lengthening. shape. color. and size ratio.
CHAPTE'
Cementation
Figs 13-78 to 13-79 fetdspathic ceramic restorations were cemented after tooth whitening and restorative treatment with a fiberglass pin.
Fig 13-72 Clinical case in which the maxillary left anterior dentition requires restoration, the central incisor with a veneer and the lateral
in cisor. canine. and both premolars with all-ceramic crowns. Fig 1 3-73 Definitive restoration immediately following cementation. Fig 13-74 Figs 13-80 and 13-81 Magnification of the central incisors before and after adhesive cementation.
Postoperative view. 3 years later. The stability of the tissues and the periodontal health confirm the validity of the operating technique. Figs 13-82 and 13-83 Excellent integration of the fetdspathic ceramic restorations.
Figs 13-75 and 13-77 Clinical case of a 32-year-old patient who wanted to replace the maxillary right lateral in cisor crown because of its poor
esthetics. Removal of the crown revealed inadequate tooth preparation. in terms of health and shape. In addition to replacing the old restora
tion after endodontic and restoration therapy. the clinician proposed restoring the two central incisors with porcelain laminate veneers. The
left central incisor had a large restoration as a result of trauma. and the right central incisor had two Class 3 com posite restorations. The
required restoration of the central incisors would give more personality to the overall smite.
1
CHAPTE'
Cementation
Figs 13-78 to 13-79 fetdspathic ceramic restorations were cemented after tooth whitening and restorative treatment with a fiberglass pin.
Fig 13-72 Clinical case in which the maxillary left anterior dentition requires restoration, the central incisor with a veneer and the lateral
in cisor. canine. and both premolars with all-ceramic crowns. Fig 1 3-73 Definitive restoration immediately following cementation. Fig 13-74 Figs 13-80 and 13-81 Magnification of the central incisors before and after adhesive cementation.
Postoperative view. 3 years later. The stability of the tissues and the periodontal health confirm the validity of the operating technique. Figs 13-82 and 13-83 Excellent integration of the fetdspathic ceramic restorations.
Figs 13-75 and 13-77 Clinical case of a 32-year-old patient who wanted to replace the maxillary right lateral in cisor crown because of its poor
esthetics. Removal of the crown revealed inadequate tooth preparation. in terms of health and shape. In addition to replacing the old restora
tion after endodontic and restoration therapy. the clinician proposed restoring the two central incisors with porcelain laminate veneers. The
left central incisor had a large restoration as a result of trauma. and the right central incisor had two Class 3 com posite restorations. The
required restoration of the central incisors would give more personality to the overall smite.
1
CHAPT:R 1 .
Cementation
1 3·86
Figs 13-88 and 13-89 Stereomicroscopic views highlighting the health and esthetic achievement of the restorations.
Fig 13-4 Frontal view in relation to the mandibular dentition: esthetic a n d anatomic integration is apparent.
Figs 13-90 and 13-g 1 Frontal and occlusal views of the natural teeth highlight the transparent in cisal effects and the natural anatomy created
Fig 13-85 Occlusal view. The only tooth not incorporated in the restoration is the left lateral incisor. for function.
Fig 13-86 Esthetic integration is evident through the stereomicroscope. The gingiva reflects periodontal health and good adaptation of the
restorations.
ig 13-87 Lateral view of the veneers under the stereomicroscope in relation to the mandibular teeth.
8
CHAPT:R 1 .
Cementation
1 3·86
Figs 13-88 and 13-89 Stereomicroscopic views highlighting the health and esthetic achievement of the restorations.
Fig 13-4 Frontal view in relation to the mandibular dentition: esthetic a n d anatomic integration is apparent.
Figs 13-90 and 13-g 1 Frontal and occlusal views of the natural teeth highlight the transparent in cisal effects and the natural anatomy created
Fig 13-85 Occlusal view. The only tooth not incorporated in the restoration is the left lateral incisor. for function.
Fig 13-86 Esthetic integration is evident through the stereomicroscope. The gingiva reflects periodontal health and good adaptation of the
restorations.
ig 13-87 Lateral view of the veneers under the stereomicroscope in relation to the mandibular teeth.
8
REFERE CES t6
o of 1 sl
.., ""0- �..· -c a"d
.a 1920473-47S :7 o'
2. .. S �� u o' �a a·a ... �p: ·

.3
a...' . 1.. E
3 . o ' E .t
P•r ,•, .. J
! a a a·
C of a :E"""
d�ra -� l :e -· 1975:33.29 -29.
- (O�e •G. A �1. ".d of If.."g 'E ade-
K1 of r C us. ! en ..· ..g ce�n· e� s eaS n a ge-era prac: e. J
Ps 19SS:L,B4lls 3 s· e· e : 192;67:5�1.
ar�o P. &a1s r m . <ann ng earon - 20. m ·r . Re D. cid.f of gss-•orwer ce ents
C lt.' of uan a ub s. rn dunng �ng anl ts reat"on o pu p enitv . J
m i 1976;21:JSS-362. en• sc 16;112o6SL�S7·

6. �n D. <oan O. r n AT e re ee of l 2L s RJ. fitzgerald . s DR. Cartneau GT. n val· 3; age P. ougas \ . >rcea n ' eers: nt n d·
e ad o r cemcDI <s from a gass·oonoer a •on of a gss-ionoer luting agen : ulpal his olog ng p Hnizaoon ald b'o e C :e; of ' .
n ooatenas 185;6o431-433· ica' oe. J m en sc 187:t14:o7�1L rnt J osdont 199: 12:111-121.

7. 2 F. e ea of te appfica•ion fol "" ng enam· 22. ertschinger C. Paul SJ. Lu hy H. Scharer P. Dual 3 . ag aru Fad-ni L Rtzmann I\ p of u� e
l tching on e adapta'oon ad adess of ad' applica •on of den 10 onding agents: Ect on ond y of hogh·"< cunng ics s trad oa aon
<e i ns [in an� SO 1oz onatschr Zahn· s rength. m l en 16:9:11S-119. amps. , ds ent 202 · :.-4'.
e <d 1977;87o712-723. 23. Craig G. Res ora 1ve ental aterials. ed to. t louis: 39. eann P. ck . Roulet Jf. aoJI adapta ion
8. msn . Faaors aing e color stabi y of y-Year oo. 197. .Lth gtass,eranic inlas ad:e lutd Y.Lth lne SS· h a • Toa ' S. H rota
rstora• � rsins. a on l cand 1983;41:11-18. 24. Wilon D. y RJ. hemical nature of cementing geL Quintsence lnt 19t:22:739-7
9. lmazato S. Tarumi H, Kobayashi K, Hiraguri H. da K. matrixs of cement formed from zinc oxide and 2· 40. a eson 0. cLundoe AC. Stirrups DR. Ta or . �ntd at Intatioal
Tshani Y. Retoonshop een the degree of con· ethoxyen2oic aciG-.ugenol liquids. J Dent Res 1974: Reinishing or porcelain by sing a reinishing 1t. J ea:h. Singaore, 105.
version and intenal dicoloration of light-actvated com SJ:146. osthet Dent 199t:6s:385-3 56. 1ning D. eson S • C1bi a R. . Com·
site. ent ater J 19S:I4o23-JO. 25. Powis DR. Folleras T. erson SA. Wilson AD. Improved 1. Hultestrom K. erxan . >lishong sstems or den· aison of luting ceents or minial retPnh\ on
w. errong JM. ed R. al IS. Color stability of adhesion of a glass-ionomer cement to dentin and tal ceramics. Aaa Ddontol Scand 193:51:229-23 . preparations. Quintessence lnt 202:)):9S-tO.
elected dal-cure comosite rsin cements. J Prosth 42. Piwowaruyk . exe . Lauer H. orensen . hear S7· Pluddeann EP. ilane Coupling gent e' o :
enamel. J Dent Res 1982;61:141-1422.
dont 193;2:24-27. bond strength or cements at zirconium and lithium dis· Plenum ss. 182.
26. Kanca J 3rd. Resin bonding to wet substrate. I. 8onding
1 L orando G, Leupold RJ. eoers JC. easurement of ilicate ceramis [abstract� J Dent Res 2o2:81(s<ial s . Watanae I. atsumura H. t uta EKt of o metal
to dentin. Quintessence lnt 192;2):)�41.
hydrstatic prssurs during simuated post cementa· issue ):401. primes on adesi' ondong \lth e I gold allo
27. wami Y, Yamamoto H. Kawai K. Ebisu S. Ea of enam·
tion. J rstet ent 195:74:5�0· 43· Wilson AD. Speciication test or the solubility and disin· rosthet ent 195:73:2-303.
el and dentin surface wetness on shear bond strength
S9· Taora Y. lmai Y. rimer or onding sin to etal. ent
12. Renstiel SF. Land MF, Crispin J. ental luting agents: A of composites. J Prosthet Dent 1998;o:2o-26. tegration or dental cements: A critical evaluation of its
rviw of e curren �terature. J Prosthet Dent

ater 195:11:H.
1998;o: 28. n . Oilo G. The efect of early water contact on glass· meaning. J Dent Res 1976:ss:721-729.
4. Cutis SR. Richards MW. eiers JC. Early erosion of glass· o. eatty MW. Swal ML. ooe BK. Phillip RW. Roert
--301. ionomer cements. Quintessence lnt 192;2):29-214-
13. Yu . 2 JM. Kipnis V, White SN. ffea of dynamic I TA. Eect of crosstin.ing agent content. monom r uc
29. Rodrigues Garcia RC. De Goes MF. Del Bel Cury . ionomer cement at crown magins. lnt Prosthodont
tionality, and reeat unit chemisty on propeties of
loading methods on cement film thickness in vitro. J lnnuence of protecting agents on the solubility of glass 1993:6:ss3-ss7.
Prosthodont 199S:4:2SI-2SS · ionomers. Am J Dent 1995;8:294-296. 4S· Negm MM. Beech DR. Grant . An evaluation of m' unilled resins. J Biomed ater Res 193:27:40 413.
61. Yoshida K. Tanagawa M. At uta . In votro olubility of
14. Lard MW. A retrospeaive study of pulpal response in 30. Caughman WF. Caughman GS, Dominy T, Schuster GS. chanical and adhesive properties of polycarbxylate and
vital adult teeth prepared for complete cverage restora· glass·ionomer cements. J Oral Rehabil 1982;9:t61-167. three types of resin and conventional luting cemenb. J
Glass-ionomer and composite resin cements: Efects on
lions at ultrahigh speed using only air coolant. J oral cells. J Proslhel Dent 1990:63:SIJ-S2t. 46. Kerby RE. cGiumphy . Holloway JA. Some physical Oral Rehabil 1998;25:28S ·291.
Prosthet ent 202;8:473-478. propeties of implant abutment luting cements. lnt J

31. Roulel JF. Degrange M. Adhesion: The Silent Revolution
15. lnnstr6m M. Reducing e ris� of ensitivity and pulpal in Dentisty. Ber1in: Quintessence, 200. Prosthodont 1992:5:321-325.
complications aker the paceent of crwns and ied
patial denturs. Quintssence lnt 196;27:673�78.
41
REFERE CES t6
o of 1 sl
.., ""0- �..· -c a"d
.a 1920473-47S :7 o'
2. .. S �� u o' �a a·a ... �p: ·

.3
a...' . 1.. E
3 . o ' E .t
P•r ,•, .. J
! a a a·
C of a :E"""
d�ra -� l :e -· 1975:33.29 -29.
- (O�e •G. A �1. ".d of If.."g 'E ade-
K1 of r C us. ! en ..· ..g ce�n· e� s eaS n a ge-era prac: e. J
Ps 19SS:L,B4lls 3 s· e· e : 192;67:5�1.
ar�o P. &a1s r m . <ann ng earon - 20. m ·r . Re D. cid.f of gss-•orwer ce ents
C lt.' of uan a ub s. rn dunng �ng anl ts reat"on o pu p enitv . J
m i 1976;21:JSS-362. en• sc 16;112o6SL�S7·

6. �n D. <oan O. r n AT e re ee of l 2L s RJ. fitzgerald . s DR. Cartneau GT. n val· 3; age P. ougas \ . >rcea n ' eers: nt n d·
e ad o r cemcDI <s from a gass·oonoer a •on of a gss-ionoer luting agen : ulpal his olog ng p Hnizaoon ald b'o e C :e; of ' .
n ooatenas 185;6o431-433· ica' oe. J m en sc 187:t14:o7�1L rnt J osdont 199: 12:111-121.

7. 2 F. e ea of te appfica•ion fol "" ng enam· 22. ertschinger C. Paul SJ. Lu hy H. Scharer P. Dual 3 . ag aru Fad-ni L Rtzmann I\ p of u� e
l tching on e adapta'oon ad adess of ad' applica •on of den 10 onding agents: Ect on ond y of hogh·"< cunng ics s trad oa aon
<e i ns [in an� SO 1oz onatschr Zahn· s rength. m l en 16:9:11S-119. amps. , ds ent 202 · :.-4'.
e <d 1977;87o712-723. 23. Craig G. Res ora 1ve ental aterials. ed to. t louis: 39. eann P. ck . Roulet Jf. aoJI adapta ion
8. msn . Faaors aing e color stabi y of y-Year oo. 197. .Lth gtass,eranic inlas ad:e lutd Y.Lth lne SS· h a • Toa ' S. H rota
rstora• � rsins. a on l cand 1983;41:11-18. 24. Wilon D. y RJ. hemical nature of cementing geL Quintsence lnt 19t:22:739-7
9. lmazato S. Tarumi H, Kobayashi K, Hiraguri H. da K. matrixs of cement formed from zinc oxide and 2· 40. a eson 0. cLundoe AC. Stirrups DR. Ta or . �ntd at Intatioal
Tshani Y. Retoonshop een the degree of con· ethoxyen2oic aciG-.ugenol liquids. J Dent Res 1974: Reinishing or porcelain by sing a reinishing 1t. J ea:h. Singaore, 105.
version and intenal dicoloration of light-actvated com SJ:146. osthet Dent 199t:6s:385-3 56. 1ning D. eson S • C1bi a R. . Com·
site. ent ater J 19S:I4o23-JO. 25. Powis DR. Folleras T. erson SA. Wilson AD. Improved 1. Hultestrom K. erxan . >lishong sstems or den· aison of luting ceents or minial retPnh\ on
w. errong JM. ed R. al IS. Color stability of adhesion of a glass-ionomer cement to dentin and tal ceramics. Aaa Ddontol Scand 193:51:229-23 . preparations. Quintessence lnt 202:)):9S-tO.
elected dal-cure comosite rsin cements. J Prosth 42. Piwowaruyk . exe . Lauer H. orensen . hear S7· Pluddeann EP. ilane Coupling gent e' o :
enamel. J Dent Res 1982;61:141-1422.
dont 193;2:24-27. bond strength or cements at zirconium and lithium dis· Plenum ss. 182.
26. Kanca J 3rd. Resin bonding to wet substrate. I. 8onding
1 L orando G, Leupold RJ. eoers JC. easurement of ilicate ceramis [abstract� J Dent Res 2o2:81(s<ial s . Watanae I. atsumura H. t uta EKt of o metal
to dentin. Quintessence lnt 192;2):)�41.
hydrstatic prssurs during simuated post cementa· issue ):401. primes on adesi' ondong \lth e I gold allo
27. wami Y, Yamamoto H. Kawai K. Ebisu S. Ea of enam·
tion. J rstet ent 195:74:5�0· 43· Wilson AD. Speciication test or the solubility and disin· rosthet ent 195:73:2-303.
el and dentin surface wetness on shear bond strength
S9· Taora Y. lmai Y. rimer or onding sin to etal. ent
12. Renstiel SF. Land MF, Crispin J. ental luting agents: A of composites. J Prosthet Dent 1998;o:2o-26. tegration or dental cements: A critical evaluation of its
rviw of e curren �terature. J Prosthet Dent

ater 195:11:H.
1998;o: 28. n . Oilo G. The efect of early water contact on glass· meaning. J Dent Res 1976:ss:721-729.
4. Cutis SR. Richards MW. eiers JC. Early erosion of glass· o. eatty MW. Swal ML. ooe BK. Phillip RW. Roert
--301. ionomer cements. Quintessence lnt 192;2):29-214-
13. Yu . 2 JM. Kipnis V, White SN. ffea of dynamic I TA. Eect of crosstin.ing agent content. monom r uc
29. Rodrigues Garcia RC. De Goes MF. Del Bel Cury . ionomer cement at crown magins. lnt Prosthodont
tionality, and reeat unit chemisty on propeties of
loading methods on cement film thickness in vitro. J lnnuence of protecting agents on the solubility of glass 1993:6:ss3-ss7.
Prosthodont 199S:4:2SI-2SS · ionomers. Am J Dent 1995;8:294-296. 4S· Negm MM. Beech DR. Grant . An evaluation of m' unilled resins. J Biomed ater Res 193:27:40 413.
61. Yoshida K. Tanagawa M. At uta . In votro olubility of
14. Lard MW. A retrospeaive study of pulpal response in 30. Caughman WF. Caughman GS, Dominy T, Schuster GS. chanical and adhesive properties of polycarbxylate and
vital adult teeth prepared for complete cverage restora· glass·ionomer cements. J Oral Rehabil 1982;9:t61-167. three types of resin and conventional luting cemenb. J
Glass-ionomer and composite resin cements: Efects on
lions at ultrahigh speed using only air coolant. J oral cells. J Proslhel Dent 1990:63:SIJ-S2t. 46. Kerby RE. cGiumphy . Holloway JA. Some physical Oral Rehabil 1998;25:28S ·291.
Prosthet ent 202;8:473-478. propeties of implant abutment luting cements. lnt J

31. Roulel JF. Degrange M. Adhesion: The Silent Revolution
15. lnnstr6m M. Reducing e ris� of ensitivity and pulpal in Dentisty. Ber1in: Quintessence, 200. Prosthodont 1992:5:321-325.
complications aker the paceent of crwns and ied
patial denturs. Quintssence lnt 196;27:673�78.
41
IN DEX
Page numbers followed by " f " denote Biocompa ibility of alloys, in cas ing
igures; those followed by "t" denote systems, 338
Silica-based and translucent restora· metal-ceramic restorations. 34 -345.
0 Elastomers
t1ons. 419 345f adhesion. in custom 1mpress•on tras,
tables. B1ologic properties of cement, 4o6 tooth preparation, 422, 426f-427f Chemical adhesion, cement mechano 270. 2 7 ! f
Decay resistance of cement. 46
Biologic width translucent restorations, 419-423. physics, 46 Dental pulp ISolation. cement atoXJdty impression materials w1th. 2 8 5
for crowns, 85f, 6 42 4f-430f Chromatic stability of cements. 407, 49f and. 46 Electrosurgey techniques. f o r s o t ussue
A
dentoging1val complex analysis, 176, 178, case presentations, 431. 434f-439f adhesive resin cements. 420 Dentin-enamel moldong technique. 2 2 2 retraction. 193. t9Bf
Abrasion materials, 92-93, 93f t8of-t83f cement categories. 407-4o8. 409f Clinical mformat1on. diagnosis and Dentogingival complex. s o t 1ssue r e rae· Epimine. in provisional prosthetis. 210
Abscesses, tooth discoloration and, 32f Bisphenol glycidyl methacylate (bis-GA) cement propeties, 405-407. 49f collection of. t-28, 11f-12f tion and. 176. 178. t8of-t83f Epinephrine. for sot tiSSue retract1on. 1
bsorption theoy of cementation. 404 composite, 210 biologic properties, 406 Clinical procedures, in treatment plan, Detail reproduCtion and disinfection, i n Epoxy rsins. for wokmg cast materials,
Accommodation, impact of magniication Bisque test, ceramic restoration esthetic working propeties, 407 IG-12, 11f-14f impression mateials. 2 7 2 . 274f 316, 318-319. 320f. 323. 325f
on, o evaluation, 395-398, 396f-397f clinical indications for. 431, 432t-433t Color-matching techniques, 58. 6o. 6tf, 62 Diagnostic waxup Esthetic evaluation
cylates, in cemen , 4o8 Bleachmg procedures, 26f-27f. 31, 32f-39f clinical problems and solutions. 408. ceramiC restorations. 374-382. 375f-381f communication with pat1ent about. 29f adhesive resin cements, 420
dditive waxup, applications of, 8, 52f-;3f Blocked color technique, ceramic restora· 41G-4 11 blocked color technique. 390, 391f laboratoy procedures for, 18. 2of-21f. cementation case studies. 431. 434f-439f
Adhesive resin cements tion evaluation, 390, 391f excess cement removal, 41 4, 416f-4 17f for working cast waxes. 326 22. 23f-27f of cements. 407. 49f
adhesion preparation, 420, 422. 423f Blowtorchblowpipe casting systems, glass-ionomer cements, 418-419 Commercial sources of cement, 4o8. 49f periodontal disease treatment and. 34f of ceramic restorations. 28. 38f-39f.
enamel-dentin hybrid layers, 42 2 335-336. 337f. 338, 339f mechanophysical cement properties, Communication with patient plaster cast preparation and. 42-43. 374-382. 398. 399f-40if
esthetic chroma test, 4 2 0 Braided retraction cords, 188, 189f 405-406 dental technician-patient relationships, 44f-45 f bisque test and inal check. 395-398
excess cement removal. 423, 427f Bruxism metal-free, nonsilica-based restorations, 56-57 prosthetic design a n d function and. 40. 41f stratiication techniques. 382. 384-394
inishing and polishing, 423, 428f-429f diagnostic waxup evaluation of, 41f 430 of laboratory procedures, 29f for provisional prosthetics. 214. 2 18f-219f heat-pressed restorations. 354. 3 55f.
mechanophysics of, 405-4o6 inish line design with, 126. 140f occlusion evaluation, 414 psychological aspects of, 57 or second-generation provisional prosthet- 356. 357f-3of
metal-free, nonsi lica-based restorations, Bur systems oveview of, 404-405 Compact retraction cords, 188 ics, 253. 2 56f-25 7f. 258. 259f-263f modiied chamfer inish line design. 146.
430 for crown preparation, 9093. 91f, 931 permanent cementation, 411-414, 413f, Compression properties, cement mechano techniques for. 48. 50f-;3f 147f-149f
operating ield protocols, 4 2 2 inish line preparation kits, 126. 127f-139f 415f physics. 405 Diamond bur design photographic documentation and, 43.
polymerization, 423, 427f for modiied chamfer design, 126, postoperative sensitivity, 41r411 Concentration levels. in crown preparation. crown procedures 46f-47f. 49f
properties of, 41-428, 428f-429f 127f-!28f, 136f pressure considerations, 408, 410 102, 104f-105f inishing using. 102. 103f prosthetic design criteria and. 40. 41f
provisional restoration and cement oscillating instruments, 153f, 154 provisional cementation, 411, 413f Condensation silicones, impression inish line repositioning and completion. of provisional prosthetics, 2 17f. 224.
removal, 419-420, 42of-421f, 422, 424f for provisional prosthetics, 224, 2 2 5f. resin-reinforced glass-ionomer cements, materials, 285 159· t64f 228f. 258
seating procedures, 423 227f 419 Construction systems for working casts. preparation guidelines. 9093, 91f. 931 psychological aspects of. 57. 59f
silica-based and translucent restorations, for working cast preparation, 319, zinc phosphate cements. 418, 420f 3 17f. 318-319. 320f-3 2tf in oscillating instruments. 153f. 154 sot tissue retradion techniques.
419 320f-3 2tf zinc polycarboxylate cements. 418 Copying. i n dental restoration, 56 working cast inish lines. 322. 323f 203f-205f
tooth preparation, 422, 426f-427f Ceramic ingots, heat -pressed ceramic Cornick's basting procedures, for soft Difusion theory of cementation, 405 in treatment plan, 18. 2of-21f, 26f-27f,
translucent restorations, 419-423, restorations, 356, 357f-358f tissue retraction, 183f Dimensional stability of impression 28. 31. 32f-39f
424f-430f
c Ceramic restorative techniques. See also Correction firing materials. 276 Eugenol-free cements. provisional cementa
Air bubbles, in impression materials, 296, CAD/CAM technology, 361-362, 363f-371f Crowns. ceramic restorations, 348, 350f-351f Dioptric functional equilibrium, impact of tion. 411. 413f
297f Canines, limits for crowns on. 84, 85f, 86 alternative materials, 348, 352f-353f ceramic restorative esthetic evaluation, magniication on. So Excess cement removal, techniques for.
Alloys for working casts, 334-338, 337f, Captek metal compound CAD/CAM technology for, 361-362, 388. 390. 390f Direct oral cavity techniques, irst-generation 414, 4t6f, 423. 427f
339f finish line repositioning and, 169f-170f 363f-371f Crowns provisional prosthetics. 246, 248f-249f
Alternative materials, metal-ceramic metal-ceramic restorations, 348, 352f-353f cervical margin, treatment at, 344-345. anatomic limits for, 84. 85f. 86 Direct patient-dental technician communi· F
restorations, 348, 3 5 2 f-353f Casting systems 345f bur instrument design, 993. 91f. 93t cation. 56;7
Aluminum chloride, for soft tissue retrac· heat-pressed ceramic restorations, 354, clinical applications, 48. 50f-51f inish lines for Disclosing pastes. for impression materials Fabrication techniques, ceramic restora
tion, t8.89, 189f, 202f 3 5 5f. 356. 35 7f-36of color matching and, 6o, 6tf, 62 designs, 108-145 assessment, 30 tions. 361-362. 363f-371f
Aluminum sulfate, for soft tissue retrac· for working casts, 335-336, 337f, 338, esthetic evaluation of, 28, 38f-39f, repositioning and completion. 152. 15 3f, Distortion of materials Failure analysis of impression materials.
tion, !89 339f 374-382, 398. 399f-40if 154· 1551. 156 impression materials. 296. 299f 296. 297f-299f
Anatomic limits, for crown prostheses, 84, Cementation techniques bisque test and inal check, 395-398. instrumentation prosthetics preparation and. 25r31. 31f-39f False root preparation. for provisional
85f. 86 adhesive resin cements, 419-428, 396f-397f high-speed instrumentation, 93-94 prosthetics. 226, 2 33f-234f
Anterior teeth 428f-429f stratiication techniques, 374-382, rotating instruments for. 90-96 Double-cord retraction techniques Feldspathic crowns, esthetic results with,
color matching for, 62 adhesion preparation, 420, 422, 423f 384f-394f scientific principles of, 86, 87f, 88. 89f, for soft tissue retraction, 192, 197f, 201 28, 33f
diagnostic waxup of, 48, 50f-53f enamel-dentin hybrid layers, 42 2 finish line designs for, 146, 147f-149f 90 Double sandwich technique, ceramic Ferrous sulfate. for soft tissue retraction.
Apicoectomy, 32f for tooth preparation. 94-96, 95f restoration evaluation. 392. 393f-394f 190
esthetic chroma test, 42 0 heat-pressed restorations, 354. 355f,
Atoxicity properties of cement, 406 selective concentration levels for, 102, 105f Fiberglass dowel, bleaching and recon
excess cement removal, 423, 427f 356, 35 7f-36of
Axial limit, for crown prostheses, 84 tooth preparation for, 94-96. 97f, 98. struction with. 33f
inishing and polishing, 423, 428f-429f layering techniques, 345, 346f-347f, 349f
99f-101f, 102, 103f-104f
E Fiber-optic systems. for surgical loupes.
operating ield protocols, 422 material properties, 344
Custom impression trays Elastic memoy. in impression materials. 67, 68f
polymerization, 423, 427f metal-ceramic crowns, 342, 343f
8 provisional restoration and cement micromargin properties, 348, 349f-352f materials and techniques for, 266. 267f. 27), 274f-275f. 276 Filling techniques. for provisional prosthet
268, 269f-270f. 270. 271f ics. 214-215. 2 2 2 , 223f

Binocular vision, impact of magnification removal, 419-420, 42of Cevical margin preparation
systems on, 8o seating procedures, 423 ceramic restorations, 348, 349f-350f modular trays. 301-302, 303f-312f
42
IN DEX
Page numbers followed by " f " denote Biocompa ibility of alloys, in cas ing
igures; those followed by "t" denote systems, 338
Silica-based and translucent restora· metal-ceramic restorations. 34 -345.
0 Elastomers
t1ons. 419 345f adhesion. in custom 1mpress•on tras,
tables. B1ologic properties of cement, 4o6 tooth preparation, 422, 426f-427f Chemical adhesion, cement mechano 270. 2 7 ! f
Decay resistance of cement. 46
Biologic width translucent restorations, 419-423. physics, 46 Dental pulp ISolation. cement atoXJdty impression materials w1th. 2 8 5
for crowns, 85f, 6 42 4f-430f Chromatic stability of cements. 407, 49f and. 46 Electrosurgey techniques. f o r s o t ussue
A
dentoging1val complex analysis, 176, 178, case presentations, 431. 434f-439f adhesive resin cements. 420 Dentin-enamel moldong technique. 2 2 2 retraction. 193. t9Bf
Abrasion materials, 92-93, 93f t8of-t83f cement categories. 407-4o8. 409f Clinical mformat1on. diagnosis and Dentogingival complex. s o t 1ssue r e rae· Epimine. in provisional prosthetis. 210
Abscesses, tooth discoloration and, 32f Bisphenol glycidyl methacylate (bis-GA) cement propeties, 405-407. 49f collection of. t-28, 11f-12f tion and. 176. 178. t8of-t83f Epinephrine. for sot tiSSue retract1on. 1
bsorption theoy of cementation. 404 composite, 210 biologic properties, 406 Clinical procedures, in treatment plan, Detail reproduCtion and disinfection, i n Epoxy rsins. for wokmg cast materials,
Accommodation, impact of magniication Bisque test, ceramic restoration esthetic working propeties, 407 IG-12, 11f-14f impression mateials. 2 7 2 . 274f 316, 318-319. 320f. 323. 325f
on, o evaluation, 395-398, 396f-397f clinical indications for. 431, 432t-433t Color-matching techniques, 58. 6o. 6tf, 62 Diagnostic waxup Esthetic evaluation
cylates, in cemen , 4o8 Bleachmg procedures, 26f-27f. 31, 32f-39f clinical problems and solutions. 408. ceramiC restorations. 374-382. 375f-381f communication with pat1ent about. 29f adhesive resin cements, 420
dditive waxup, applications of, 8, 52f-;3f Blocked color technique, ceramic restora· 41G-4 11 blocked color technique. 390, 391f laboratoy procedures for, 18. 2of-21f. cementation case studies. 431. 434f-439f
Adhesive resin cements tion evaluation, 390, 391f excess cement removal, 41 4, 416f-4 17f for working cast waxes. 326 22. 23f-27f of cements. 407. 49f
adhesion preparation, 420, 422. 423f Blowtorchblowpipe casting systems, glass-ionomer cements, 418-419 Commercial sources of cement, 4o8. 49f periodontal disease treatment and. 34f of ceramic restorations. 28. 38f-39f.
enamel-dentin hybrid layers, 42 2 335-336. 337f. 338, 339f mechanophysical cement properties, Communication with patient plaster cast preparation and. 42-43. 374-382. 398. 399f-40if
esthetic chroma test, 4 2 0 Braided retraction cords, 188, 189f 405-406 dental technician-patient relationships, 44f-45 f bisque test and inal check. 395-398
excess cement removal. 423, 427f Bruxism metal-free, nonsilica-based restorations, 56-57 prosthetic design a n d function and. 40. 41f stratiication techniques. 382. 384-394
inishing and polishing, 423, 428f-429f diagnostic waxup evaluation of, 41f 430 of laboratory procedures, 29f for provisional prosthetics. 214. 2 18f-219f heat-pressed restorations. 354. 3 55f.
mechanophysics of, 405-4o6 inish line design with, 126. 140f occlusion evaluation, 414 psychological aspects of, 57 or second-generation provisional prosthet- 356. 357f-3of
metal-free, nonsi lica-based restorations, Bur systems oveview of, 404-405 Compact retraction cords, 188 ics, 253. 2 56f-25 7f. 258. 259f-263f modiied chamfer inish line design. 146.
430 for crown preparation, 9093. 91f, 931 permanent cementation, 411-414, 413f, Compression properties, cement mechano techniques for. 48. 50f-;3f 147f-149f
operating ield protocols, 4 2 2 inish line preparation kits, 126. 127f-139f 415f physics. 405 Diamond bur design photographic documentation and, 43.
polymerization, 423, 427f for modiied chamfer design, 126, postoperative sensitivity, 41r411 Concentration levels. in crown preparation. crown procedures 46f-47f. 49f
properties of, 41-428, 428f-429f 127f-!28f, 136f pressure considerations, 408, 410 102, 104f-105f inishing using. 102. 103f prosthetic design criteria and. 40. 41f
provisional restoration and cement oscillating instruments, 153f, 154 provisional cementation, 411, 413f Condensation silicones, impression inish line repositioning and completion. of provisional prosthetics, 2 17f. 224.
removal, 419-420, 42of-421f, 422, 424f for provisional prosthetics, 224, 2 2 5f. resin-reinforced glass-ionomer cements, materials, 285 159· t64f 228f. 258
seating procedures, 423 227f 419 Construction systems for working casts. preparation guidelines. 9093, 91f. 931 psychological aspects of. 57. 59f
silica-based and translucent restorations, for working cast preparation, 319, zinc phosphate cements. 418, 420f 3 17f. 318-319. 320f-3 2tf in oscillating instruments. 153f. 154 sot tissue retradion techniques.
419 320f-3 2tf zinc polycarboxylate cements. 418 Copying. i n dental restoration, 56 working cast inish lines. 322. 323f 203f-205f
tooth preparation, 422, 426f-427f Ceramic ingots, heat -pressed ceramic Cornick's basting procedures, for soft Difusion theory of cementation, 405 in treatment plan, 18. 2of-21f, 26f-27f,
translucent restorations, 419-423, restorations, 356, 357f-358f tissue retraction, 183f Dimensional stability of impression 28. 31. 32f-39f
424f-430f
c Ceramic restorative techniques. See also Correction firing materials. 276 Eugenol-free cements. provisional cementa
Air bubbles, in impression materials, 296, CAD/CAM technology, 361-362, 363f-371f Crowns. ceramic restorations, 348, 350f-351f Dioptric functional equilibrium, impact of tion. 411. 413f
297f Canines, limits for crowns on. 84, 85f, 86 alternative materials, 348, 352f-353f ceramic restorative esthetic evaluation, magniication on. So Excess cement removal, techniques for.
Alloys for working casts, 334-338, 337f, Captek metal compound CAD/CAM technology for, 361-362, 388. 390. 390f Direct oral cavity techniques, irst-generation 414, 4t6f, 423. 427f
339f finish line repositioning and, 169f-170f 363f-371f Crowns provisional prosthetics. 246, 248f-249f
Alternative materials, metal-ceramic metal-ceramic restorations, 348, 352f-353f cervical margin, treatment at, 344-345. anatomic limits for, 84. 85f. 86 Direct patient-dental technician communi· F
restorations, 348, 3 5 2 f-353f Casting systems 345f bur instrument design, 993. 91f. 93t cation. 56;7
Aluminum chloride, for soft tissue retrac· heat-pressed ceramic restorations, 354, clinical applications, 48. 50f-51f inish lines for Disclosing pastes. for impression materials Fabrication techniques, ceramic restora
tion, t8.89, 189f, 202f 3 5 5f. 356. 35 7f-36of color matching and, 6o, 6tf, 62 designs, 108-145 assessment, 30 tions. 361-362. 363f-371f
Aluminum sulfate, for soft tissue retrac· for working casts, 335-336, 337f, 338, esthetic evaluation of, 28, 38f-39f, repositioning and completion. 152. 15 3f, Distortion of materials Failure analysis of impression materials.
tion, !89 339f 374-382, 398. 399f-40if 154· 1551. 156 impression materials. 296. 299f 296. 297f-299f
Anatomic limits, for crown prostheses, 84, Cementation techniques bisque test and inal check, 395-398. instrumentation prosthetics preparation and. 25r31. 31f-39f False root preparation. for provisional
85f. 86 adhesive resin cements, 419-428, 396f-397f high-speed instrumentation, 93-94 prosthetics. 226, 2 33f-234f
Anterior teeth 428f-429f stratiication techniques, 374-382, rotating instruments for. 90-96 Double-cord retraction techniques Feldspathic crowns, esthetic results with,
color matching for, 62 adhesion preparation, 420, 422, 423f 384f-394f scientific principles of, 86, 87f, 88. 89f, for soft tissue retraction, 192, 197f, 201 28, 33f
diagnostic waxup of, 48, 50f-53f enamel-dentin hybrid layers, 42 2 finish line designs for, 146, 147f-149f 90 Double sandwich technique, ceramic Ferrous sulfate. for soft tissue retraction.
Apicoectomy, 32f for tooth preparation. 94-96, 95f restoration evaluation. 392. 393f-394f 190
esthetic chroma test, 42 0 heat-pressed restorations, 354. 355f,
Atoxicity properties of cement, 406 selective concentration levels for, 102, 105f Fiberglass dowel, bleaching and recon
excess cement removal, 423, 427f 356, 35 7f-36of
Axial limit, for crown prostheses, 84 tooth preparation for, 94-96. 97f, 98. struction with. 33f
inishing and polishing, 423, 428f-429f layering techniques, 345, 346f-347f, 349f
99f-101f, 102, 103f-104f
E Fiber-optic systems. for surgical loupes.
operating ield protocols, 422 material properties, 344
Custom impression trays Elastic memoy. in impression materials. 67, 68f
polymerization, 423, 427f metal-ceramic crowns, 342, 343f
8 provisional restoration and cement micromargin properties, 348, 349f-352f materials and techniques for, 266. 267f. 27), 274f-275f. 276 Filling techniques. for provisional prosthet
268, 269f-270f. 270. 271f ics. 214-215. 2 2 2 , 223f

Binocular vision, impact of magnification removal, 419-420, 42of Cevical margin preparation
systems on, 8o seating procedures, 423 ceramic restorations, 348, 349f-350f modular trays. 301-302, 303f-312f
42
: Index
Final check procedures, ceramic restoration Gingival margrns detail reproduction and disrnfection, 272, lntracrevicular restoration margins, posi· ock-ups, inish line design and use of,
esthetic evaluauon, 395-398, 396f-397f for crowns, 8sf. 86 274f uoning of, 174, 175f, 176, 177f, 179f 126, 143f
Finish lines esthetrc considerations, 22, 23f dimensional stability, 276 Investing procedures, for working casts, agnrication systems odeling techniques, for woking casts,
so· and !))·degree shoulder designs, finish line design and, 126, t3of-t3tf distortion, 296, 299f 332. 334-335 dental applicauons of. 64. 6sf. 6 326-327. 329f-33tf
114, 115f. 118f metal-ceramic restorations, 342, 343f elastic memoy, 273, 274f-275f. 276 Irregularities. 1n Impression materials, 296, Galilean system. 6, 8f odular custom impression trays,
0-degree shoulder design, 117, 122f-123f outlinrng of, 22. 23f failure analysis, 296. 297f-299f 298f instrumentation, 6-70, 8f-71f 301-)02, 303f-312f
area finish line designs, to8, 109t, 110, provisional prosthetics in1sh line Irregularities, 296, 299f instrument maintenance, 81
tl1f, 112, 113f infiltration, 210 for ixed restorations, 272-273. optical microscopes, 76. 79f
assembled preparation k1ts for, 124, 126, preparation, for, 224, 226. 228f-235f 274l-275f. 276-277. 278f-279f. 280 j overuse of, 70
N
127f-14sf Gingival retraction. Se Sot tissue retraction luidity and viscosity, 273 Juxtagingival restoration margins. positioning physiologic efects and system mainte· Noble metal alloys, for working casts,
ceramic restorative esthetic evaluation, Glass-ionomer cements, 418-419, 431 hydrophilic behavior. 277 of, 174, 175f, 176. 177f, 179f nance. So 335-336. 337f. 338. 339f
388, 390, 390f Greenough stereomicroscope, properties implant-supported restorations, )oo-Jo2, prismatic system, 66-67, 8f, 811 Nonrotat1ng instruments. Se also
classic chamfer design, 116, 119f, 146 of, n. 73f 30Jf-Jt2f stereomicroscopes. 71-76. 73f. 75f-79f, Oscillaung instruments
counter-chamfer design, 117, 124, 125f Grit levels impression techniques. 287-294 K 811 inish line des1gn and, 120, 142f
in crown preparation, 98, 102, 103f bur design and, 92-93, 93f, 95f irregular-shaped holes, 296, 298f Knitted retraction cords, t88, t89f axillay teeth
designs for. 108, 109f, t09t. 110, mf inish line repositioning and completion, mixing procedures, 280, 283f. 284 Kois's bone-sounding technique, dento· color matching of, 62
impression materials 1)4. 1)7t modular custom trays, 301-302, 303f-312f gingival complex analysis, 178, t8of restoration of, 48. 51f-s2f 0
irregularities in, 296. 299f oscillating instruments, 153f, 154 one-step heavy-light impression Kuwata's three-plane theory Mclean technique for tooth preparation. Objective esthetics, treatment planning
placement of, 277, 278f-279f Guide groove preparation, finish line techniques, 34f-35f for crown preparation, 98, to)f 98, totf and, 28
linear finish line designs, 109t, 112-114, design and, 126. 135f one-step/one-paste technique, 287-288, metal-ceramic restorations. 342, 343f Mechanical fabrication techniques. ceramic Occlusion evaluation
11)f 289f restorations, 361-362, 363f-371f in cementation procedures, 414
modified chamfer design, 117, 123f-12 sf. one-step/two· or three-paste technique, Mechanical retraction techniques, for sot for crown prostheses, 84
124, 126, 127-u8f, 136f, 146, 147-149f H 288, 290f-29tf, 292. 294f L tissue. 184. t86f in dental arch, 22, 23f
oscillating instruments for, 152, t53f, 154. Heating parameters, in provisional plaster cast roughness/powdey surface. Labial stratiication echanical theoy of cementation. 404 Occtusogingival height. crown preparation
tS)f, 1)6 prosthetics, 210 296. 299f ceramic restorative esthetic evaluation. echanicochemical retraction techniques. and. 8, 89f, 90
repOSitioning of, 152. 153f Heat-pressed restorations, techniques for, polyethers, 285-286, 287t 38)-386, 386f-387f for sot tissue. 184. t86f-t87f One-iring ceramic stratiication techniques,
restoration margin and positioning of, 354, 35 5f, 356. 3 57f-36of polysulides. 284-285 inish line design and, 126, 136f-137f echanophysical cement properties, 382. 384-390. 38sf-39of
174. 17)f, 176, t77f. 179f Heidemann spatula, for provisional polvinyl siloxanes. 286 Labial wax veneers, clinical applications of, 405-4o6 One-step heay-light impression tech
shon/rounded shoulder chamfer design, prosthetic fillings, 21), 222, 22Jf, nsf preparation of, 29-31, 31f-39f 53. 53f Metal·ceramic restoration niques, 34f-35f
116-117, 120f-t2tf High-speed hand instruments reversible hydrocolloids, 284 Laboratory procedures, in treatment plan, casting systems for, 336, 338, 339f One-step/one-paste technique, or impres·
simple line designs, 109t. 114, 116-124 concentration levels for, 102. t04f-10sf rough/irregular surfaces, 296 t8, t9f-2tf, 22 esthetic results with, 28 sions, 287-288, 289f
sonic vs ultrasonic instruments, 156, crown preparation, 93-94. 95f tear strength, 276-277, 278f-279f Lacquer applications, working cast inish inish line repositioning. 17tf-172f One-step/two· or three-paste technique, for
1)7f. 1)8, t6of-t6)f Hori2ontal gingival retraction, 184 thermal expansion, 280 applications. 322-323, 323f-325f opaque dentin technique, 384. 386f impressions, 288, 290f-291f. 292. 294f
tooth preparation guidelines for, 146, clinical guidelines for, 199, 200f thixotropy, 276 Laminate veneers shoulder technique. 382, 384. 385f Opalescence. in ceramic restorations,
147f-149f Hydrocolloids two-step/two-paste (putty wash) tech esthetic results with. 28 soft tissue retraction techniques, 178, 377-379, 38of-38tf
on working casts, preparation of, reversible hydrocolloids for impression nique, 292-293. 294f-295f heat-pressed ceramic restorations. 356, t82f-t8Jf, 200f Opaque dentin technique, metal-ceramic
322-323, 323f-325f materials, 284 wettability, 273, 2741 357f-3s8f techniques for, 342, 343f restoration. 384. 386f
First-generation provisional prosthetics for working casts, 317f, 318 for working casts Lava system scanner. ceramic restoration wax panem construction. 327-328, Operating ield isolation
direct oral cavity technique for. 246, Hydrophilic behavior, of impression alloys, 335 fabrication, 361-362, 362f-371f 329f-33tf adhesive resin cement preparation. 422.
248f-249f materials, 277 analysis of. 316, 317f Layering techniques, ceramic restorations, Metal-free, nonsilica-based restorations, 424f-425f
indirect silicone index. 247, 252, 254f-255f basic properties of. 316, 318 345. 346f-347f. 349f adhesive resin cements. 430 permanent prosthetic techniques. 412.
indirect stone-cast technique for, wax materials. 326 Le (ron-type instrumentation, wax patten Microleakage, absence of. in cement, 4o6 4t3f
246-247. 249f-2)tf Incisors construction. 328, 329f-331f Micromargins Optical microscopes, basic properties of.
properties of, 211, 2 12f-213f finish line design and, 126, 137f Lip proile, photographic documentation ceramic restorations, 348, 349f-350f 76. 79f
Implant-supported restorations, impression
Fluidity, in impression materials, 273 limits for crowns on, 8sf. 86 of. 43. 47f fabrication techniques, 362. 371f Oral luid solubility, cement mechano·
materials for, )oo-Jo2, 303f-312f
Fluorescence, ceramic restoration evalua Indirect patient-dentist-dental technician Long-term provisional prosthetics. 210, inish line design and. 126, t)of physics. 405
Impregnating chemicals. for sot tissue
tions, 382, 383f 214, 223f Micromechanical adhesion Oral hygiene. treatment plan management
retraction. t88-t90, t89f, 202f communication, s6
Lost-wax technique cement mechanophysics. 405-4o6 and. to, 12. t6f-17f. 34f-36f
Impression materials Indirect techniques, first-generation provi
heat-pressed ceramic restorations, 354, postoperative sensitivity, 41o-411 Orderly disordered stratiication, ceramic
air bubbles in, 296, 297f sional prosthetics, 246-247, 249f-251f,
G 252. 254l-2ssf Jssf. 356 Mineralized tissue adhesion, cement restorations, 375-377, 377f-379f
application range evaluation, 280, 282f
Galilean surgical loupes, 66, 68f working cast investment, 332 mechanophysics. 405-406 Orderly stratiication, ceramic restorations.
condensation silicones, 285 In situ evaluation of provisional prosthet·
Mixing procedures for impression materials, 374-375. 376f
Gingival damage, finish line repositioning custom impression trays, 266, 267f, 268, ics. 258
280, 283f. 284
and completion, t53f, 154, t62f, 269f-270f, 270, 27tf Instrument maintenance issues, in magnifi
t66f-t67f cation systems, 8t
cement mixing, 412
: Index
Final check procedures, ceramic restoration Gingival margrns detail reproduction and disrnfection, 272, lntracrevicular restoration margins, posi· ock-ups, inish line design and use of,
esthetic evaluauon, 395-398, 396f-397f for crowns, 8sf. 86 274f uoning of, 174, 175f, 176, 177f, 179f 126, 143f
Finish lines esthetrc considerations, 22, 23f dimensional stability, 276 Investing procedures, for working casts, agnrication systems odeling techniques, for woking casts,
so· and !))·degree shoulder designs, finish line design and, 126, t3of-t3tf distortion, 296, 299f 332. 334-335 dental applicauons of. 64. 6sf. 6 326-327. 329f-33tf
114, 115f. 118f metal-ceramic restorations, 342, 343f elastic memoy, 273, 274f-275f. 276 Irregularities. 1n Impression materials, 296, Galilean system. 6, 8f odular custom impression trays,
0-degree shoulder design, 117, 122f-123f outlinrng of, 22. 23f failure analysis, 296. 297f-299f 298f instrumentation, 6-70, 8f-71f 301-)02, 303f-312f
area finish line designs, to8, 109t, 110, provisional prosthetics in1sh line Irregularities, 296, 299f instrument maintenance, 81
tl1f, 112, 113f infiltration, 210 for ixed restorations, 272-273. optical microscopes, 76. 79f
assembled preparation k1ts for, 124, 126, preparation, for, 224, 226. 228f-235f 274l-275f. 276-277. 278f-279f. 280 j overuse of, 70
N
127f-14sf Gingival retraction. Se Sot tissue retraction luidity and viscosity, 273 Juxtagingival restoration margins. positioning physiologic efects and system mainte· Noble metal alloys, for working casts,
ceramic restorative esthetic evaluation, Glass-ionomer cements, 418-419, 431 hydrophilic behavior. 277 of, 174, 175f, 176. 177f, 179f nance. So 335-336. 337f. 338. 339f
388, 390, 390f Greenough stereomicroscope, properties implant-supported restorations, )oo-Jo2, prismatic system, 66-67, 8f, 811 Nonrotat1ng instruments. Se also
classic chamfer design, 116, 119f, 146 of, n. 73f 30Jf-Jt2f stereomicroscopes. 71-76. 73f. 75f-79f, Oscillaung instruments
counter-chamfer design, 117, 124, 125f Grit levels impression techniques. 287-294 K 811 inish line des1gn and, 120, 142f
in crown preparation, 98, 102, 103f bur design and, 92-93, 93f, 95f irregular-shaped holes, 296, 298f Knitted retraction cords, t88, t89f axillay teeth
designs for. 108, 109f, t09t. 110, mf inish line repositioning and completion, mixing procedures, 280, 283f. 284 Kois's bone-sounding technique, dento· color matching of, 62
impression materials 1)4. 1)7t modular custom trays, 301-302, 303f-312f gingival complex analysis, 178, t8of restoration of, 48. 51f-s2f 0
irregularities in, 296. 299f oscillating instruments, 153f, 154 one-step heavy-light impression Kuwata's three-plane theory Mclean technique for tooth preparation. Objective esthetics, treatment planning
placement of, 277, 278f-279f Guide groove preparation, finish line techniques, 34f-35f for crown preparation, 98, to)f 98, totf and, 28
linear finish line designs, 109t, 112-114, design and, 126. 135f one-step/one-paste technique, 287-288, metal-ceramic restorations. 342, 343f Mechanical fabrication techniques. ceramic Occlusion evaluation
11)f 289f restorations, 361-362, 363f-371f in cementation procedures, 414
modified chamfer design, 117, 123f-12 sf. one-step/two· or three-paste technique, Mechanical retraction techniques, for sot for crown prostheses, 84
124, 126, 127-u8f, 136f, 146, 147-149f H 288, 290f-29tf, 292. 294f L tissue. 184. t86f in dental arch, 22, 23f
oscillating instruments for, 152, t53f, 154. Heating parameters, in provisional plaster cast roughness/powdey surface. Labial stratiication echanical theoy of cementation. 404 Occtusogingival height. crown preparation
tS)f, 1)6 prosthetics, 210 296. 299f ceramic restorative esthetic evaluation. echanicochemical retraction techniques. and. 8, 89f, 90
repOSitioning of, 152. 153f Heat-pressed restorations, techniques for, polyethers, 285-286, 287t 38)-386, 386f-387f for sot tissue. 184. t86f-t87f One-iring ceramic stratiication techniques,
restoration margin and positioning of, 354, 35 5f, 356. 3 57f-36of polysulides. 284-285 inish line design and, 126, 136f-137f echanophysical cement properties, 382. 384-390. 38sf-39of
174. 17)f, 176, t77f. 179f Heidemann spatula, for provisional polvinyl siloxanes. 286 Labial wax veneers, clinical applications of, 405-4o6 One-step heay-light impression tech
shon/rounded shoulder chamfer design, prosthetic fillings, 21), 222, 22Jf, nsf preparation of, 29-31, 31f-39f 53. 53f Metal·ceramic restoration niques, 34f-35f
116-117, 120f-t2tf High-speed hand instruments reversible hydrocolloids, 284 Laboratory procedures, in treatment plan, casting systems for, 336, 338, 339f One-step/one-paste technique, or impres·
simple line designs, 109t. 114, 116-124 concentration levels for, 102. t04f-10sf rough/irregular surfaces, 296 t8, t9f-2tf, 22 esthetic results with, 28 sions, 287-288, 289f
sonic vs ultrasonic instruments, 156, crown preparation, 93-94. 95f tear strength, 276-277, 278f-279f Lacquer applications, working cast inish inish line repositioning. 17tf-172f One-step/two· or three-paste technique, for
1)7f. 1)8, t6of-t6)f Hori2ontal gingival retraction, 184 thermal expansion, 280 applications. 322-323, 323f-325f opaque dentin technique, 384. 386f impressions, 288, 290f-291f. 292. 294f
tooth preparation guidelines for, 146, clinical guidelines for, 199, 200f thixotropy, 276 Laminate veneers shoulder technique. 382, 384. 385f Opalescence. in ceramic restorations,
147f-149f Hydrocolloids two-step/two-paste (putty wash) tech esthetic results with. 28 soft tissue retraction techniques, 178, 377-379, 38of-38tf
on working casts, preparation of, reversible hydrocolloids for impression nique, 292-293. 294f-295f heat-pressed ceramic restorations. 356, t82f-t8Jf, 200f Opaque dentin technique, metal-ceramic
322-323, 323f-325f materials, 284 wettability, 273, 2741 357f-3s8f techniques for, 342, 343f restoration. 384. 386f
First-generation provisional prosthetics for working casts, 317f, 318 for working casts Lava system scanner. ceramic restoration wax panem construction. 327-328, Operating ield isolation
direct oral cavity technique for. 246, Hydrophilic behavior, of impression alloys, 335 fabrication, 361-362, 362f-371f 329f-33tf adhesive resin cement preparation. 422.
248f-249f materials, 277 analysis of. 316, 317f Layering techniques, ceramic restorations, Metal-free, nonsilica-based restorations, 424f-425f
indirect silicone index. 247, 252, 254f-255f basic properties of. 316, 318 345. 346f-347f. 349f adhesive resin cements. 430 permanent prosthetic techniques. 412.
indirect stone-cast technique for, wax materials. 326 Le (ron-type instrumentation, wax patten Microleakage, absence of. in cement, 4o6 4t3f
246-247. 249f-2)tf Incisors construction. 328, 329f-331f Micromargins Optical microscopes, basic properties of.
properties of, 211, 2 12f-213f finish line design and, 126, 137f Lip proile, photographic documentation ceramic restorations, 348, 349f-350f 76. 79f
Implant-supported restorations, impression
Fluidity, in impression materials, 273 limits for crowns on, 8sf. 86 of. 43. 47f fabrication techniques, 362. 371f Oral luid solubility, cement mechano·
materials for, )oo-Jo2, 303f-312f
Fluorescence, ceramic restoration evalua Indirect patient-dentist-dental technician Long-term provisional prosthetics. 210, inish line design and. 126, t)of physics. 405
Impregnating chemicals. for sot tissue
tions, 382, 383f 214, 223f Micromechanical adhesion Oral hygiene. treatment plan management
retraction. t88-t90, t89f, 202f communication, s6
Lost-wax technique cement mechanophysics. 405-4o6 and. to, 12. t6f-17f. 34f-36f
Impression materials Indirect techniques, first-generation provi
heat-pressed ceramic restorations, 354, postoperative sensitivity, 41o-411 Orderly disordered stratiication, ceramic
air bubbles in, 296, 297f sional prosthetics, 246-247, 249f-251f,
G 252. 254l-2ssf Jssf. 356 Mineralized tissue adhesion, cement restorations, 375-377, 377f-379f
application range evaluation, 280, 282f
Galilean surgical loupes, 66, 68f working cast investment, 332 mechanophysics. 405-406 Orderly stratiication, ceramic restorations.
condensation silicones, 285 In situ evaluation of provisional prosthet·
Mixing procedures for impression materials, 374-375. 376f
Gingival damage, finish line repositioning custom impression trays, 266, 267f, 268, ics. 258
280, 283f. 284
and completion, t53f, 154, t62f, 269f-270f, 270, 27tf Instrument maintenance issues, in magnifi
t66f-t67f cation systems, 8t
cement mixing, 412
�---e�
Oscillatmg instruments Polyethers clinical considerations and procedures, R Rotating Instruments. See also Oscillat�ng double-cord techniques for. 192-19).
inish line repositioning and. 152, t S J f, in impregnating materials. 189-190. 189f 210 mstruments. 1971 t98f
1 5 4 . t s s r. 156 for i m pression materials, 285-286, 287t diagnostic considerations. 238. 239f. Rad1ograph1C opaCity of cements. 407. bur des1gn, 90-93. 91f, 931 g�ngival retraction techniques. 184.
optimization of, 158-t59. t66f-172f Polymerization, adhesive resin cements, 24o-241. 242f-245f 4091 for crown preparation. 90-96 tBsf 187f
sonic vs ultrasonic comparisons. 156. 42), 4271 filling stage. 214-215. 222, 2 2 3 f Radiosca\pels and radiosurgery, for soft impregnating chemicals for. t88-190. 189f
1 5 7 f, 1 5 71 . 158 Polysulfides. for i m pression materials, finishing. 224. 225f-226f tissue retract 1on. 193. 198f mechanical techniques. 184. t8of. 190.
Overcontounng, prosthesis errors and, 3 1 284-285 first-generation. 211. 2 t 2f-2 t ) f Reduction groove preparation. inish line
s 1911. 192· 193- 1941- 197f
Polyurethane resins, for working cast long-term provisionals. 214, 223f design and. 126. t)6f. 141f Sandwich technique, for provisional pros mechanochemical techniques, 184.
materials. 316, )t8-Jt9, 320f, 3 2 3 . 325f mock-up procedures. 239f, 24D-241, Refractive indices. ceramic restoration t86f t87f. 1Q, 19tf, 192-19). 194f-t97f
p
thetics. 2 2 2
Polyvinyl siloxanes 2421-2451 evaluations. 377-379. 38of-38tf Second-generation provisional prosthetics. for provisional prosthetics, 224. 226.
Palatal stratiication for I m pression materials. 286 second-generation. 214, 2 t6f-217f Removal preparation and technique, for 214. 2t6f 2t?f. 222, 226 2281 2 ) 5 1
ceramic restorative esthetic evaluation. for soh tissue retraction. 189 short-term provisionals. 2 1 1 . 2t2f-2t)f. working casts. 332, 333f stone cast techniques for. 252-253. restoration marg1n positioning, 1 7 4 . 175f.
)88, )891 Postoperative sensitivity, cement restora· 214 Resin techniques. See also Cementation 256f-257f. 258. 259f-263f 176. t77f. 1791
finish line design and. 126, t)6f-137f tions, 4tG-4tt in s i t u evaluation. 2 5 8 techniques. Selective double-cord retraction technique. retract1on cords. t88. 189f
Papillae preparation. for provisional pros Precision techniques third-generation, 214, 2 t8f-2 2 1 f adhesive resin cements. 419-420. 4211. for soh tissue retraction. 192. 1961 surgiCal techmques for. 184. 193. 198f
thetiCS, 226. 2 3 3 f ceramic restorations. )6t-)62, )62f-37tf tissue conditioning. 224, 226, 422-42), 4241-4291. 430 Serial extractions. for provisional prosthetics, tear strength of impression materials
Patient-dental technician relationships, provisional prosthetics, 214. 2t6f-217f 2281-2)51 custom i m pression trays, 266. 267f. 268, 214. 2 19f-22of and. 277. 278f-279f
56-57 filling for, 2 1 5 restoration configuration and execution. 2691-2701, 270. 27tf Setting times, for cements. 407 working cast in1sh lines. )22-J2J.
Patient try-in. for impression materials. 30, on working casts 361 first-generation provisional prosthetics. Shon-term provisional prosthetics, proper 32Jf-325f
)If finish line preparation, 322-32), thickness errors in. 31 246-247. 252. 254l-255f ties of. 208, 2 1 1 . 2 t 2f-2t)f. 214 Solubility, cement mechanophysics. 405
Pattern creation for working casts, 3 2 J f-325f zirconium oxide materials, 361 g\ass-ionomer cements. 419, 4 3 1 Shoulder techniques. metal-ceramic Sonic instruments
)26-)28, )291-)) tf. ) ) 2 guidelines for, 326 Provisional prosthetics f o r provisional prosthetic fillings. 215. restoration. 382. 384. 385f inish line repositioning w1th. 152. tSJf.
Periodontal pathology Pressed-shell technique, 211. 2 1 2 f cementation techniques. 411 2 2 2 , 2231 Silica-based restorations. adhesive resin 154. tssr. 156. t6of t6tf
biotype evaluation, 178, t8of Pressure parameters, cement restorations. characteristics and classification, 208. for working cast materials, 316. )t8-319, properties. 419 ultrasonic instruments compared with,
finish line design and. 126, 134f 408, 410 2091. 2 1 0 )201. )2), )251 Silicone dies. for work1ng casts, 317f. 156. 157f. 1571. 158
provisional prosthetics. 210 Prismatic surgical \oupes clinical considerations and procedures, 2 1 0 Restorations )18-)19 Stein's tooth preparation technique. 98.
tear strength of impression materials basic properties of. 66-67. 681 diagnostic techniques. 238. 2 39f. cement application and seating. 412. Silicon dioxide alloys. working cast invest tool
and, 277, 278f-279f clinical applications and instrumentation. 24-241, 2421-2451 414. 4151. 423 ment, 332 Stereomicroscope techniques
treatment plan management and, to, 1 2 . 66-?0, 681-?tf filling stage. 214-215. 222. 2 2 3 f defined. 57 Silicones. for impression materials. 285 accessories for. 72. 73f
t6f-t7f stereomicroscopes vs, Stt finishing, 2 2 4 , 2 2 5 f-226f impression materials for, 30o-302. Silicone index advantages and disadvantages of. 66
treatment protocols for. 34f-36f Prosthetics. See also Crowns. irst-generation, 2 1 1 , 2 1 2 f-2 1 3 f 30)f-)t2f clinical applications of, 54- s s r basic components of. 64. 65 f
Peri pheral velocity rule, bur design and, AD/AM technology for, )6t-)62, direct o r a l cavity technique for, 246, margin positioning for, 174. 175f. 176, in first-generation provisional prosthetics. clinical applications for. 72. 7)1, 77f-?9f
92-93 )6)f-)71f 2481-2491 17?1. 1791 211, 213f inish line repositioning and, 162f.
Phenolates, in cement, 407 ceramics for indirect silicone index. 247, 2 5 2 , Restorative dimensional test. for cement indirect techniques, 247. 252. 254l-255f !66f-t67f
Phosphate-bonded casting investments. alternative materials, 348, JS2f-JsJf 2541-2551 prosthetics, 412 i n second-generation provisional prosthet· historical background on. 64
working casts, 332, 334-335, 334f cevical margin, treatment a t . 344-345. indirect stone-cast technique for. Restorative material adhesive properties, ics. 253. 256f-257f. 258. 259f-263f for impression materials assessment. JO.
Phosphates, in cement, 407 3451 246-247, 249f-251f cement mechanophysics, 406 Single-cord retraction technique, for soft ) If, )7f
Photographic documentation heat-pressed restorations. 354, 3 5 5 f, in situ evaluation of, 258 Retraction cord techniques tissue retract ion. 190. 191f, 192 prismatic systems compared with, 8tt
color matching and, 58, 6o. 6tf, 62 356, 3 5 7 f-)6of clinical guidelines for. 193. 199. 2oof clinical guidelines for. 2oof. 201. types of. 71, 73f
long-term provisiona\s, 210, 214. 223f
of prosthetics, 43. 46f-47f, 49f layering techniques, 345, 346f-347f, 349f mock-up procedures for, 2 39f. 24-24t. for crown preparation. 98 202f-205f Stone cast techniques
Physiologic efects of magnification material properties. 344 double-cord techniques. 192, 197f Single-tooth restorations, laboratory proce· for irst-generation provisional prosthetics.
242f-245f
for finish lines dures. 18. 2of 247. 249f-251f
systems, So metal-ceramic crowns, 342, 343f removal of, 411, 4tJf, 419-420, 420f
design and. 126, 138f Sintodent resin. for provisional prosthetics, for second-generation provisional pros·
Plaster casts micromargin properties, 348, 349f-352f second-generation. 214, 2t6f-2t7f, 2 2 2 .
repositioning and. 159. t6)f-t6sf 222 thetics. 252 -253. 2561 2 5 7f. 258.
powdery irregularities in, 296, 299f color matching for, sB. 6o, 6tf, 62 226
for provisional prosthetics, 184. t88, 189f. Smile 259f-263f
preparation techniques, 42-43, 44f-45f design and function criteria, 40, 41f stone cast techniques for, 252-253.
215. 222, 22)1 inish line design evaluation and. 146. 149f Stratiication techniques. ceramic restorative
properties of, 316, 318 fabrication mechanics and stages, 256f-257f. 258. 259f-263f
selective double-cord technique, 192. 1961 photographic documentation of, 43. 46f esthetic evaluation with. 374 382.
treatment plan and role of, 18, 2of-21f 361-)62, 3631-3711 short-term provisiona\s, 208. 211,
single-cord technique, 190. 19tf. 192, Soft tissue retraction 3841- 3941
Plaster veneer waxup, applications for, 48, photographic documentation, 43. 46f-47f, 2 1 2f-2t3f. 214
194f-195f clinical guidelines. 193. 199. 199f-204f. labial stratification, 385·386. 386f-387f
53, 5 3 f 491 third-generation. 214, 218f-2 2 t f
Retrograde obturation, )21-))f 201 palatal stratification. )88. 389f
Polish ing guidelines preparations of, 2-Jl, ) t f-39f tissue conditioning, 2 2 4 , 2 2 6 , 228f-235f
Reversible hydrocolloids. for impression dentogingival complex analysis of, 176. Stress testing, of impression materials.
adhesive resin cements, 423, 428f-429f provisional prosthetics Psychologic aspects of communication
materials. 284 178, t8of-t8Jf 2?6-277
for provisional prosthetics, 224, 227f characteristics and classification, 208, with patients, 57, 59f
Polycarboxylates, i n cement, 408 2091. 210 Putty wash technique, for i m pressions.
292-293 - 2941-295 1
47
�---e�
Oscillatmg instruments Polyethers clinical considerations and procedures, R Rotating Instruments. See also Oscillat�ng double-cord techniques for. 192-19).
inish line repositioning and. 152, t S J f, in impregnating materials. 189-190. 189f 210 mstruments. 1971 t98f
1 5 4 . t s s r. 156 for i m pression materials, 285-286, 287t diagnostic considerations. 238. 239f. Rad1ograph1C opaCity of cements. 407. bur des1gn, 90-93. 91f, 931 g�ngival retraction techniques. 184.
optimization of, 158-t59. t66f-172f Polymerization, adhesive resin cements, 24o-241. 242f-245f 4091 for crown preparation. 90-96 tBsf 187f
sonic vs ultrasonic comparisons. 156. 42), 4271 filling stage. 214-215. 222, 2 2 3 f Radiosca\pels and radiosurgery, for soft impregnating chemicals for. t88-190. 189f
1 5 7 f, 1 5 71 . 158 Polysulfides. for i m pression materials, finishing. 224. 225f-226f tissue retract 1on. 193. 198f mechanical techniques. 184. t8of. 190.
Overcontounng, prosthesis errors and, 3 1 284-285 first-generation. 211. 2 t 2f-2 t ) f Reduction groove preparation. inish line
s 1911. 192· 193- 1941- 197f
Polyurethane resins, for working cast long-term provisionals. 214, 223f design and. 126. t)6f. 141f Sandwich technique, for provisional pros mechanochemical techniques, 184.
materials. 316, )t8-Jt9, 320f, 3 2 3 . 325f mock-up procedures. 239f, 24D-241, Refractive indices. ceramic restoration t86f t87f. 1Q, 19tf, 192-19). 194f-t97f
p
thetics. 2 2 2
Polyvinyl siloxanes 2421-2451 evaluations. 377-379. 38of-38tf Second-generation provisional prosthetics. for provisional prosthetics, 224. 226.
Palatal stratiication for I m pression materials. 286 second-generation. 214, 2 t6f-217f Removal preparation and technique, for 214. 2t6f 2t?f. 222, 226 2281 2 ) 5 1
ceramic restorative esthetic evaluation. for soh tissue retraction. 189 short-term provisionals. 2 1 1 . 2t2f-2t)f. working casts. 332, 333f stone cast techniques for. 252-253. restoration marg1n positioning, 1 7 4 . 175f.
)88, )891 Postoperative sensitivity, cement restora· 214 Resin techniques. See also Cementation 256f-257f. 258. 259f-263f 176. t77f. 1791
finish line design and. 126, t)6f-137f tions, 4tG-4tt in s i t u evaluation. 2 5 8 techniques. Selective double-cord retraction technique. retract1on cords. t88. 189f
Papillae preparation. for provisional pros Precision techniques third-generation, 214, 2 t8f-2 2 1 f adhesive resin cements. 419-420. 4211. for soh tissue retraction. 192. 1961 surgiCal techmques for. 184. 193. 198f
thetiCS, 226. 2 3 3 f ceramic restorations. )6t-)62, )62f-37tf tissue conditioning. 224, 226, 422-42), 4241-4291. 430 Serial extractions. for provisional prosthetics, tear strength of impression materials
Patient-dental technician relationships, provisional prosthetics, 214. 2t6f-217f 2281-2)51 custom i m pression trays, 266. 267f. 268, 214. 2 19f-22of and. 277. 278f-279f
56-57 filling for, 2 1 5 restoration configuration and execution. 2691-2701, 270. 27tf Setting times, for cements. 407 working cast in1sh lines. )22-J2J.
Patient try-in. for impression materials. 30, on working casts 361 first-generation provisional prosthetics. Shon-term provisional prosthetics, proper 32Jf-325f
)If finish line preparation, 322-32), thickness errors in. 31 246-247. 252. 254l-255f ties of. 208, 2 1 1 . 2 t 2f-2t)f. 214 Solubility, cement mechanophysics. 405
Pattern creation for working casts, 3 2 J f-325f zirconium oxide materials, 361 g\ass-ionomer cements. 419, 4 3 1 Shoulder techniques. metal-ceramic Sonic instruments
)26-)28, )291-)) tf. ) ) 2 guidelines for, 326 Provisional prosthetics f o r provisional prosthetic fillings. 215. restoration. 382. 384. 385f inish line repositioning w1th. 152. tSJf.
Periodontal pathology Pressed-shell technique, 211. 2 1 2 f cementation techniques. 411 2 2 2 , 2231 Silica-based restorations. adhesive resin 154. tssr. 156. t6of t6tf
biotype evaluation, 178, t8of Pressure parameters, cement restorations. characteristics and classification, 208. for working cast materials, 316. )t8-319, properties. 419 ultrasonic instruments compared with,
finish line design and. 126, 134f 408, 410 2091. 2 1 0 )201. )2), )251 Silicone dies. for work1ng casts, 317f. 156. 157f. 1571. 158
provisional prosthetics. 210 Prismatic surgical \oupes clinical considerations and procedures, 2 1 0 Restorations )18-)19 Stein's tooth preparation technique. 98.
tear strength of impression materials basic properties of. 66-67. 681 diagnostic techniques. 238. 2 39f. cement application and seating. 412. Silicon dioxide alloys. working cast invest tool
and, 277, 278f-279f clinical applications and instrumentation. 24-241, 2421-2451 414. 4151. 423 ment, 332 Stereomicroscope techniques
treatment plan management and, to, 1 2 . 66-?0, 681-?tf filling stage. 214-215. 222. 2 2 3 f defined. 57 Silicones. for impression materials. 285 accessories for. 72. 73f
t6f-t7f stereomicroscopes vs, Stt finishing, 2 2 4 , 2 2 5 f-226f impression materials for, 30o-302. Silicone index advantages and disadvantages of. 66
treatment protocols for. 34f-36f Prosthetics. See also Crowns. irst-generation, 2 1 1 , 2 1 2 f-2 1 3 f 30)f-)t2f clinical applications of, 54- s s r basic components of. 64. 65 f
Peri pheral velocity rule, bur design and, AD/AM technology for, )6t-)62, direct o r a l cavity technique for, 246, margin positioning for, 174. 175f. 176, in first-generation provisional prosthetics. clinical applications for. 72. 7)1, 77f-?9f
92-93 )6)f-)71f 2481-2491 17?1. 1791 211, 213f inish line repositioning and, 162f.
Phenolates, in cement, 407 ceramics for indirect silicone index. 247, 2 5 2 , Restorative dimensional test. for cement indirect techniques, 247. 252. 254l-255f !66f-t67f
Phosphate-bonded casting investments. alternative materials, 348, JS2f-JsJf 2541-2551 prosthetics, 412 i n second-generation provisional prosthet· historical background on. 64
working casts, 332, 334-335, 334f cevical margin, treatment a t . 344-345. indirect stone-cast technique for. Restorative material adhesive properties, ics. 253. 256f-257f. 258. 259f-263f for impression materials assessment. JO.
Phosphates, in cement, 407 3451 246-247, 249f-251f cement mechanophysics, 406 Single-cord retraction technique, for soft ) If, )7f
Photographic documentation heat-pressed restorations. 354, 3 5 5 f, in situ evaluation of, 258 Retraction cord techniques tissue retract ion. 190. 191f, 192 prismatic systems compared with, 8tt
color matching and, 58, 6o. 6tf, 62 356, 3 5 7 f-)6of clinical guidelines for. 193. 199. 2oof clinical guidelines for. 2oof. 201. types of. 71, 73f
long-term provisiona\s, 210, 214. 223f
of prosthetics, 43. 46f-47f, 49f layering techniques, 345, 346f-347f, 349f mock-up procedures for, 2 39f. 24-24t. for crown preparation. 98 202f-205f Stone cast techniques
Physiologic efects of magnification material properties. 344 double-cord techniques. 192, 197f Single-tooth restorations, laboratory proce· for irst-generation provisional prosthetics.
242f-245f
for finish lines dures. 18. 2of 247. 249f-251f
systems, So metal-ceramic crowns, 342, 343f removal of, 411, 4tJf, 419-420, 420f
design and. 126, 138f Sintodent resin. for provisional prosthetics, for second-generation provisional pros·
Plaster casts micromargin properties, 348, 349f-352f second-generation. 214, 2t6f-2t7f, 2 2 2 .
repositioning and. 159. t6)f-t6sf 222 thetics. 252 -253. 2561 2 5 7f. 258.
powdery irregularities in, 296, 299f color matching for, sB. 6o, 6tf, 62 226
for provisional prosthetics, 184. t88, 189f. Smile 259f-263f
preparation techniques, 42-43, 44f-45f design and function criteria, 40, 41f stone cast techniques for, 252-253.
215. 222, 22)1 inish line design evaluation and. 146. 149f Stratiication techniques. ceramic restorative
properties of, 316, 318 fabrication mechanics and stages, 256f-257f. 258. 259f-263f
selective double-cord technique, 192. 1961 photographic documentation of, 43. 46f esthetic evaluation with. 374 382.
treatment plan and role of, 18, 2of-21f 361-)62, 3631-3711 short-term provisiona\s, 208. 211,
single-cord technique, 190. 19tf. 192, Soft tissue retraction 3841- 3941
Plaster veneer waxup, applications for, 48, photographic documentation, 43. 46f-47f, 2 1 2f-2t3f. 214
194f-195f clinical guidelines. 193. 199. 199f-204f. labial stratification, 385·386. 386f-387f
53, 5 3 f 491 third-generation. 214, 218f-2 2 t f
Retrograde obturation, )21-))f 201 palatal stratification. )88. 389f
Polish ing guidelines preparations of, 2-Jl, ) t f-39f tissue conditioning, 2 2 4 , 2 2 6 , 228f-235f
Reversible hydrocolloids. for impression dentogingival complex analysis of, 176. Stress testing, of impression materials.
adhesive resin cements, 423, 428f-429f provisional prosthetics Psychologic aspects of communication
materials. 284 178, t8of-t8Jf 2?6-277
for provisional prosthetics, 224, 227f characteristics and classification, 208, with patients, 57, 59f
Polycarboxylates, i n cement, 408 2091. 210 Putty wash technique, for i m pressions.
292-293 - 2941-295 1
47
Index
Subjective esthetics. treatment planning Torque multipliers, on high-speed hand pattern construction, 327-328,
a n d, 28 instruments. 9394. 95f 329f-331f
Supragingival restoration margins, posi· Total occlusal convergence TOC) principle Wettability, of impression materials, 273,
tioning of, 174, 175f, 176, 177f, 179f crown preparation and, 86. 87f, 88, 90 274f
Su rface properties finish line design and, 126, 13 2f-133f Whitening. See Bleaching procedures
ceramic restorations Translucent restorations, adhesive resin Working casts
color evaluation, 377, 377f-379f propeties, 419 alloys for, 335
inishing evaluation, 395. 396f-397f, 398 Treatment plan casting systems for, 335-336, 337f. 338,
impression materials, rough/i rregular clinical procedures for, 1o-12 , nf-14f 339f
surfaces, 296 management of, 1o-21 construction system and methods. 317f,
metal·ceramic restorations. 342, 343f Tricodent Model System, for working cast 318-319, 320f-321f
Surgical loupes preparation. 319. 320f-3 21f finish line preparation, 322-323,
accessories for, 67, 68f nsv Gel 323f-325f
clinical applications and instrumentation, in casting systems. 338 finish line repositioning and, 169f
66, 68f-nf. 70 metal-ceramic restorations, 345. 345f impression analysis, 316, 317f
Galilean system, 66, 68f Tungsten carbide bur design investing procedures, 332, 334-335
prismatic system, 66-67, 68f, 81t for crown preparation. 9-93, 91f, 93t materials for, 316, 318
Surgical retraction techniques, for soft for provisional prosthetics, 224, 227f modeling techniques for, 326-327,
tissue, 193, 198f Twisted retraction cords, 188, 189f 329f-331f
Two-step/two-paste (putty wash) technique, precision work, 326
for im pressions, 292-293, 294f-295f preparation of, 29-31, 31f-39f
T removal preparation and technique, 332,
Team·based prosthetic planning, 2 2 , 28-29 333f
Tear strength, of impression materials,
u wax materials for, 326
276-277, 278f-279f Ultrasonic instruments wax pattern creation, 326-328,
Telecamera video camera, for surgical finish line repositioning with, 152, 153f, 329f-331f, 332
lou pes, 67, 68f 154. 155f, 156 Working properties of cements, 407
Telescopic stereomicroscopes, properties sonic instruments compared with, 156,
of, 71, 73f 157f, 157t. 158
Tensile strength, cement mechanophysics,
y
405 Yttrium oxide, ceramic restorations, 361
Thermal expansion, impression materials,
v
280 Vertical gingival retract ion, 184
Third·generation provisional prosthetics. Viscosity
z
214, 218f-221f cement mechanophysics, 405 Zeiser construction system, for working
Thixotropy, of im pression materials, 276 in impression materials, 273 casts, 318
Tooth preparation, for prosthetics Zinc phosphate cements, 408, 418, 420f,
cleaning procedures, 412 43D-431
inish line design and, 146, 147f-149f w Zinc polycarboxylate cements, 418, 431
preliminary procedures, 9496, 97f Wax materials Zirconium oxide, ceramic restorations,
separation stage, 94 custom impression trays, 267f, 268, 361-362
systematized procedures for, 96, 98, 269f-270f, 270, 271f Zirconium oxide eugenol cements,
99f-101f, 102, 103f-104f for working casts, 326 provisional cementation, 411

Precision in Dental Esthetics PDF

Uploaded by

Copyright:

Available Formats

Precision in Dental Esthetics PDF

Uploaded by

Document Information

Original Title

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

Precision in Dental Esthetics PDF

Uploaded by

Copyright:

Available Formats

I

€ 220,00 9 788874 920112

gi\t·� IIH' rru•r-� and ,('fllrit� in all tiling..

/(omNJ Pust·rllfl DOMENICO MASSIRONI, MD, DMD

GIUSEPPE ROMEO, MDT

Dental Laboratory Technician and Owner, Turin, Italy

Quintessenza Edizioni Sri

Istanbul, Sao Paulo, Mumbai, Moscow, Prague, and Warsaw

gi\t·� IIH' rru•r-� and ,('fllrit� in all tiling..

/(omNJ Pust·rllfl DOMENICO MASSIRONI, MD, DMD

GIUSEPPE ROMEO, MDT

Dental Laboratory Technician and Owner, Turin, Italy

Quintessenza Edizioni Sri

Istanbul, Sao Paulo, Mumbai, Moscow, Prague, and Warsaw

Estetica e precisione: Procedure cliniche e di laboratorio

ldndg re • TrectmP 1' }I n

Magri"iC1' on SysteM> Used 11 )en• s•ny

Phys1o,gic 'T<cts and llSt umH • tn•er dllC'

©2007 Quintessenza Edizioni Sri

Quintessenza Edizioni Sri

20017 Passirana di Rho (MI)

System at 1ed tooth prepdrat un

Editors of the English Edition: Lisa C. Bywaters and Bryn Goates

Finish Line Destgns for Cotrple't Crown

Estetica e precisione: Procedure cliniche e di laboratorio

ldndg re • TrectmP 1' }I n

Magri"iC1' on SysteM> Used 11 )en• s•ny

Phys1o,gic 'T<cts and llSt umH • tn•er dllC'

©2007 Quintessenza Edizioni Sri

Quintessenza Edizioni Sri

20017 Passirana di Rho (MI)

System at 1ed tooth prepdrat un

Editors of the English Edition: Lisa C. Bywaters and Bryn Goates

Finish Line Destgns for Cotrple't Crown

C tntc I . O'lSidH !'tor> or Pr)Vts on I

TEc'l'l cal Corsiderat ons for Proviston

ilr li r o)ierT' d SO IL 'Ions

C tntc I . O'lSidH !'tor> or Pr)Vts on I

TEc'l'l cal Corsiderat ons for Proviston

ilr li r o)ierT' d SO IL 'Ions

ventional and implant-supported fixed prosthodontics using a stereomicroscope. A

diplomate of the International Congress of Oral lmplantologists since 1998, Mr Pascetta

La Precisione nela restaurazione protesica (Precision in Prosthetic Restorative Treatment;

Quintessenza, 1993) with Dr Domenico Massironi and Alberto Battistelli.

prosthodontics and esthetic restorations. Mr Romeo presents at conferences and seminars

stereomicroscope, he focuses on prosthodontics and implant dentistry in his multidisci­

Precisione nela restaurazione protesica (Precision in Prosthetic Restorative Treatment;

Quintessenza, 1993). He has presented numerous seminars and symposia in prestigious

Esthetic Dentisty as well as a diplomate of the International Congress of Oral

ventional and implant-supported fixed prosthodontics using a stereomicroscope. A

diplomate of the International Congress of Oral lmplantologists since 1998, Mr Pascetta

La Precisione nela restaurazione protesica (Precision in Prosthetic Restorative Treatment;

Quintessenza, 1993) with Dr Domenico Massironi and Alberto Battistelli.

prosthodontics and esthetic restorations. Mr Romeo presents at conferences and seminars

stereomicroscope, he focuses on prosthodontics and implant dentistry in his multidisci­

Precisione nela restaurazione protesica (Precision in Prosthetic Restorative Treatment;

Quintessenza, 1993). He has presented numerous seminars and symposia in prestigious

Esthetic Dentisty as well as a diplomate of the International Congress of Oral

Professor Dr Peter Scharer, DMD, MS*

stereomicroscope, he focuses on prosthodontics and implant dentistry in his multidisci

stereomicroscope, he focuses on prosthodontics and implant dentistry in his multidisci