• Remineralization making restauration • Filling • Inlay/onlay • crown https://www.karger.com/Article/PDF/224210 The aim of filling restoration beside removing the caries • Preparing the tooth for filling are called TOOTH (CAVITY) PREPARATION
• retention • resistance • shape • function • aesthetic https://www.nycdentist.com/more/teaching-private- practice/photomicrographs-sem-of-dental-histology/ Influencing factors of the preparation • Diagnosis, extension of the caries • Characteristic of the enamel and the dentin • Articulation, axis deviation, anatomy • Retention of tooth structures • Properties of filling materials • Oral hygiene NOMENCLATURE Surface: unprepared part Wall: prepared part Cavosurface angle or margin: the junction of the surface and the wall Inner walls: Outer walls Line angle: the junction of two occlusopulpal axiopulpal walls Point angle: the junction of three walls Cemento-enamel Nomenclature: the nearest junction anatomical structure Occlusal, approximal (mesial, distal),axial, pulpal, gingival, vestibular (labial, buccal), oral (lingual, palatinal), apical Classification of cavity 1914. G.V. Black • Base: „the predilection places of caries” on the anatomical crown: I.-V. classes • Later will be added : • Not predilection place: VI. class • Not on the anatomical crown: Root surface caries
• Predilection areas:These places have no self-cleaning!
1. fissures, pits 2. approximally, under the contact point 3. in between the equator and the gingiva 4. root surface Class I. • Cavity preparation from all pit and fissure caries • fissures of premolars and molars • Pits- foramen coecum • Upper first molars on the palatinal surface • Lower first molars on the buccal surface • Upper lateral incisor on the oral surface https://www.dentalnotebook.com/caries-lesion-classification-g-v-black/ Class II. • Cavities on the proximal surface of posterior (premolar and molar) teeth • Smooth surface caries • M(O); (O)D; M(O)D; (toward or from the midline)
https://nepaldentalspa.com/dental-caries-tooth-decay/ Class III. Cavities on the proximal surface of anterior teeth not involving the incisial angle
https://www.casemasters.com/posts/59c0aa65b365c77e9c10b5a2 Class IV. • Cavities on the proximal surfaces of anterior teeth involving the incisial angle
https://www.styleitaliano.org/step-by-step-for-class-iv-restorations/ Class V. Cavities on the gingival third of the anatomical crown. These can be on the facial or lingual surfaces of all teeth. Not pit and fissure cavities!
https://www.dentalnotebook.com/caries-lesion-classification-g-v-black/ Class VI. Cavities on the incisial edge of anterior teeth or on the occlusal cusp heights of posterior teeth. Not predilection place!
https://dentodontics.com/2015/02/26/g-v-blacks- http://www.dentistrytoday.com/ce-articles/272-conservative- classification-of-carious-lesions/ treatment-of-the-worn-dentition-with-adhesive-composite-resin Root surface caries • Caries begins on the root surface (clinical crown) • cement (not with enamel covered surface)! • Predilection place!
https://www.quora.com/What-are-root-caries-and-how-are-they-different-from-regular-cavities-caries BASIC PREPARATION DESIGN Depends on the filling material and the extension of caries • CONVENTIONAL: • For amalgam, metal inlay, rootsurface caries (planning composite filling) • Macroretention • Box-like cavity, special enamel margin, secondary retention are used very often
• BEVELED CONVENTIONAL: • Earlier amalgam was the filling material and now we are going to change that for composite • Macro- and microretention (box shape and bevel prep.)
• MODIFIED, or ADHESIVE or MINIMAL-INVASIV:
• No special walls, line angles and point angles! • Only carious tooth structure is going to be removed, and cavosurface margin gonna be prepared beveling (composite) • Microretentintion GENERAL RULES OF CAVITY PREPARATION I.INITIAL STAGE II. FINAL STAGE (primer steps) (secunder steps)
1. outline form and initial depth 1. removal of infected dentin and old 2. primary resistance form filling 3. primary retention form 2. pulp protection 4. convinience form 3. secondary resistance and retention form 4. finishing the prepared walls 5. cleaning, inspecting…
Out of date: „extension for prevention ”
If we consider the principles and the filling materials, we can close up the steps. INITIAL STAGE Determination of the outline form, and initial depth
High speed (170-200.000 rpm) with water cooling, diamond
or hard metal bur (FG). The shape of the bur depends on the caries!
Main rules: 1. Healthy tooth structure should be preserved 2. All friable enamel should be removed 3. All faults should be include in cavity 4. The outline of the filling should be shortened 5. Maximum 0,2-0,8mm in the dentin FACTORS INFLUENCING THE OUTLINE FORM 1. The extension of carious lesion 2. Aesthetic considerations 3. Occlusal relationship 4. Adjacent tooth position 5. Anatomical features of the tooth
Preserve the strength of marginal ridge and the strength of the cusps. Decision: about keeping or reduction of the cusps. http://www.dentalcetoday.com/courses/63/html/dt_section_4.htm
• Keeping: extension of caries is less than half of the distance (50 %)
between the primer fissure and the heigth of the cusp . • Considerable: if the distance is between 50% and 75% • Reduction: extension of caries is bigger, than 2/3 (75%) of the distance. MEGTARTÓ FOGÁSZAT ÉS ENDODONCIA, SZERK.FAZEKAS ÁRPÁD If the distance between two prepared cavities <0,5mm- connect it PRIMARY RETENTION FORM Definition: Preparation resists displacement or removal of the restoration from tipping or lifting forces.
Retention is influenced by the contact between the
restorative material and tooth. • macromechanical: amalgam • micromechanical: composite • chemical: glassionomer, polycarboxylate cement http://intranet.tdmu.edu.ua/data/kafedra/internal/stomat_ter_dit/classes_stud/en/stomat/ntn/P
• inlay/onlay (indirect rest.): metal, esthetics Amalgam Inlay(metal) • filling (direct rest.): amalgam, composite https://www.slideshare.net/AdwitiVidushi/fundamentals-in-tooth-preparation-conservative-dentistry PRIMARY RESISTANCE FORM Definition: both of the tooth and restoration can withstand without fracture the masticatory forces.
Preparation: primary retention and resistance form are
Principles: • shape, flat floor, slightly rounded line angles • thickness of restorative material • walls: parallel, divergent or convergent
CONVINIENCE FORM MEGTARTÓ FOGÁSZAT ÉS ENDODONCIA, SZERK.FAZEKAS ÁRPÁD
FINAL STEPS OF CAVITY PREPARATION
• removal of infected dentin and old filling
• pulp protection if it’s required (direct, indirect) • secondary resistance and retention form • finishing the prepared walls • cavity cleaning, drying, inspection… Removal of any remaining infected dentin and/or old restorative material Carious dentin Old restoration should be removed, if: Difference between carious and healthy • negativly affect the new one dentin in practice • compromise the retention • in color (whitish, brown) • caries is under the filling • Hardness (soft, hard) • the pulp was sympthomatic preoperatively Instruments: • the periphery of remaining filling is not • Caries indicator, intact • sharp excavator, Amalgam removing: carbide bur • steel/ carbide round bur (rubberdam and/or exhaustor) • Micromotor (blue, green) Composite removing: diamond 1.000-4.500-6.000 rpm bur, carbide
Dr. Zsófia Bata Caries therapy, cavity classification, nomenclature, cavity preparation Removal of any remaining infected dentin and/or old restorative material and pulp protection • Concave prepared area • DO NOT deepened the whole occlusopulpal / axiopulpal wall • pulp protection if it is needed (direct/indirect pulp capping) X
MEGTARTÓ FOGÁSZAT ÉS ENDODONCIA, SZERK.FAZEKAS ÁRPÁD
• Etching, priming and bonding. • This is not really considered as part of the tooth preparation! MEGTARTÓ FOGÁSZAT ÉS ENDODONCIA, SZERK.FAZEKAS ÁRPÁD Beveled enamel margins (Secondary resistance and retention forms )
• Metal inlay (better adaptation between the inlay and tooth
structure) • Composite filling ( more enamel surface for adhesive technic ) • Amalgam- NO BEVELING!!! 90 degrees cavosurface angle
• 0,5-1mm width • Healty, supported enamel prisms!!! • Beveling oclusally is CONTRAINDICATED because of masticatory forces Finishing the prepared walls The aim of finishing: • is to create the best marginal seal between the restorative material and tooth. • afford a smooth marginal junction • provide maximum strength of both the tooth and filling near the margin.
Finishing: • Micromotor (accelerator) 10.000-40.000 rpm • Materia: diamond, hardmetal • Shank: FG • Bur shape: depends on the shape of the cavity wall • Grit size: fine, extra fine • Hardmetal bur’s edges: 16, 18 Cleaning, drying, inspection Check out the cavity from every way: • is there any opacity ? • is there any unsupported enamel ? • are the walls enough hard ? • are the indirectly visualised areas enough clean ? • are the orificies, pulp chamber closed ? • are the walls prepared in a good angle? • are the walls enough hard ?
Removing the debris from the cavity, cleaning and drying:
• Benzin J Dent Res. 2007 Jan; 86(1): 90–94. • Chlorhexidin gluconat 2% (inhibition of MMP) Chlorhexidine Preserves Dentin Bond in vitro M. R. O. Carrilho,1,4 R. M. Carvalho,2 M. F. de • water Goes,1 V. di Hipólito,1 S. Geraldeli,3 F. R. Tay,4 D. H. Pashley,4 and L. Tjäderhane5,* Thank you for your kind attention!
