DENTAL TECHNIQUE

Functionally suitable digital removable complete

dentures: A dental technique
Kehui Deng, BM,a Yong Wang, MS, SCI,b Yongsheng Zhou, DDS, PhD,c and Yuchun Sun, DDS, PhDd

Traditional removable com- ABSTRACT

plete dentures have a long
This article describes a technique for fabricating removable complete dentures by using digital
history; however, limitations technology which aims to produce an individually designed, diagnostic, complete denture. This
include the long treatment technology could reduce the number of appointments compared with traditional complete
period,1,2 a difficult procedure denture treatment and has a wide range of applications for different types of edentulous
that depends heavily on the patients, including those with severe resorption of the alveolar ridge or a high occlusal force.
experience and skill of the Furthermore, the low cost of 3D printers, compared with expensive milling machines, may make
dentist, and a definitive den- the approach more accessible. (J Prosthet Dent 2019;-:---)
ture that typically requires
repeated adjustment or even reworking after denture accurate and better border extension of the impression so
delivery.3 Few dentists have the ability to fabricate a as to improve retention and comfort of the denture.6
suitable removable complete denture, and many younger Moreover, a clinical evaluation of the denture is highly
dentists are reluctant to provide complete dentures.4 recommended in those systems to reduce the possibility
In the recent years, digital technology has been used of inappropriate fit or poor esthetics, requiring another
in a more efficient manner than traditional methods for appointment visit.7 The protocol for a milled denture
5
complete dentures. Commercial digital complete den- base bonded to artificial teeth is widely used in
ture systems, such as AvaDent (Global Dental Science commercially available complete denture systems. The
LLC), Dentca (Dentca Inc), and Baltic (Merz Dental advantage is the lack of polymerization shrinkage of the
GmbH), can provide the denture at the second visit (not milled blank compared with traditional denture bases.
including a clinical evaluation), which is the most expe- However, it is not suitable for patients with a strong
dient of the existing commercially available systems.3 occlusal force who require a metal reinforcing baseplate
However, the 1-step impression method those systems in their denture or those with reduced vertical di-
use may not be suitable for all patients, such as for those mensions, in whom there is insufficient interalveolar
with severe alveolar resorption. In such patients, a 2-step space to generate the integrated teeth location hole on
impression method is recommended to acquire more the denture base in the software.8

This work was supported by the National Key R&D Program of China (2018YFB1106900); Capital’s Funds for Health Improvement and Research (2018-2-4103); Program
for New Clinical Techniques and Therapies of Peking University School and Hospital of Stomatology (PKUSSNCT-18G01).
a
Doctoral candidate, Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital
and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital
Stomatology & National Clinical Research Center for Oral Diseases, Beijing, PR China.
b
Professor, Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and
Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital
Stomatology and National Clinical Research Center for Oral Diseases, Beijing, PR China.
c
Professor, Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of
Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, PR China.
d
Professor, Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and
Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital
Stomatology and National Clinical Research Center for Oral Diseases, Beijing, PR China.

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Figure 1. A, Maxillary primary impression. B, Vertical view of primary jaw relation record. C, Front view of primary jaw relation record. D, Mandibular
primary impression.

Therefore, to simplify the clinical operation proced- Ask the patient to occlude until the distance be-
ures and widen the scope of application, a functionally tween the 2 points reaches the previously measured
suitable digital complete denture (FSD) is described in occlusal vertical dimension. Place silicone impres-
this article. A diagnostic denture was designed and sion material (Heavy Body Regular Set; Ivoclar
fabricated by using this technique to make a definitive Vivadent AG) onto the impression paste that is on
impression to confirm the occlusal relation and esthetics the back of the tray to record an accurate jaw rela-
so the denture can be delivered on the third visit. tion (Fig. 1B), marking the midline, maxillary canine
line, the smile line, and upper lip line position as the
TECHNIQUE information for the follow-up design of the diag-
nostic denture (Fig. 1C).
1. Select aluminum trays suitable for the patient’s 3. Scan the primary impressions and jaw relation re-
alveolar arch at the first visit and make primary cord on a 3D scanner (Dentscan Y500; Nanjing
impressions by using a modeling plastic impression Geosmart3D Information Technology Co Ltd). Up-
compound (Red; Shanghai Rong Xiang Dental load the standard tessellation language (STL) data
Material Co, Ltd), presoftened in approximately into complete denture design software (Hoteamsoft
70  C water. Precut the anterior labial side of the Co Ltd) to design the FSD diagnostic denture
maxillary tray and restore the lip support with (Fig. 2A). Design the margin of the denture base
impression paste (Fig. 1). 2-mm inward from the margin of the impression to
2. Draw 2 points on the nasal point and chin of the allow space for border molding and offsetting the
patient. Use a ruler to measure the distance be- tissue surface by 1 mm to contain the impression
tween the 2 points as the rest vertical dimension material (Fig. 2B). Design the spherical tissue stops
and subtract 2 mm from this distance to achieve the on the intaglio of the diagnostic denture to help it
occlusal vertical dimension. Place the maxillary seat accurately in the mouth (Fig. 2C). Then, use a
aluminum tray with softened impression paste 3D printer (0.8 mm diameter nozzle, Lingtong II;
applied on the back of it into the patient’s mouth. Beijing Sinotech Co Ltd) to print the diagnostic

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Figure 2. Computer-aided design of complete denture. A, Appropriate Figure 3. Diagnostic complete denture. A, B, Definitive impression of
dentition template selected. B, Completed design. C, Tissue stops on maxilla and mandible. C, Definitive jaw relation record and esthetic
intaglio of diagnostic denture. confirmation.

denture by using polylactic acid (PLA; Beijing Sino (Variotime Light Flow; Kulzer GmbH) to make
tech Co Ltd). definitive impressions (Fig. 3A, 3B). Verify the
4. Place the FSD diagnostic denture into the patient’s intercuspal position stability of diagnostic denture,
mouth at the second visit, primary verifying the grinding if necessary, then record the occlusion
extension, jaw relation of the diagnostic denture. when it is stable (Fig. 3C) using the above
Add wax or shorten the dentition to adjust the mentioned light-body silicone. Use the closed-
vertical dimension if it is not appropriate. Examine mouth technique to border mold and make the
lip support and other esthetic parameters. Use definitive impression. When border molding and
heavy-body silicone impression material (Heavy making impressions, the opposing diagnostic den-
Body Regular Set; Ivoclar Vivadent AG) for func- ture should be in the mouth, and the impression
tional border molding and light-body silicone material polymerized with the patient in occlusion.

Deng et al THE JOURNAL OF PROSTHETIC DENTISTRY

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Figure 4. A, Definitive casts mounted on articulator with polylactic acid pattern located. B, Maxillary and mandibular prostheses invested with silicone
impression material. C, Mandibular arch flasked. D, Artificial teeth inserted into sockets.

Figure 5. A, Insertion of complete denture. B, Complete denture with metal framework and baseplate.

Finally, use a marking pen to correct the esthetic mount them in an articulator (average value artic-
information if there is any adjustment required. ulator; Basic System). Ensure the PLA denture
5. Scan the definitive impressions and import the data pattern is completely seated on the casts (Fig. 4A).
into complete denture design software (Hoteamsoft Wrap the dentition part with silicone impression
Co Ltd) to design complete dentures. Use a highly material (Zetalabor; Zhermack Group), flask, and
accurate 3D printer (0.4 mm diameter nozzle, heat with water. After deflasking, remove the soft-
Lingtong I; Beijing Sinotech Co Ltd) to print the ened pattern and insert the artificial teeth of the
complete denture pattern by using PLA material. same brand and model as in the design software
Pour gypsum casts (Die Stone; Kulzer GmbH) and into the tooth location sockets (Fig. 4B-D). Fill the

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mold with acrylic resin, heat-polymerize, deflask, matching between the milled base and teeth could have
adjust the occlusion by remounting the dentures on errors in the position of teeth that would require additional
an articulator, and polish the denture. clinical adjustment. However, polymerization shrinkage of
6. Deliver the definitive complete denture at the third the denture base with traditional processing cannot be
visit and evaluate the vertical dimension, jaw rela- avoided. Integrated 3D printing may be the future, but
tion, retention, stability, phonetics, and esthetics biosafety and strength, abrasion resistance, and esthetics
(Fig. 5). of printed dentures are still to be investigated.

SUMMARY
DISCUSSION
This article describes a digital technique for the fabrica-
FSD technology can reduce the number of treatments for
tion of a complete denture that can simplify the clinical
complete dentures to 3 (or 2, which requires designing
process, reduce the number of patient visits, and improve
and printing the diagnostic denture at chair-side). Based
the fitness of denture.
on a straightforward primary impression and jaw relation
record, FSD diagnostic dentures similar to the definitive
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denture combined with the traditional laboratory process, Corresponding author:

which can replace the more complicated manual tooth Dr Yuchun Sun
arrangement. This method has a wide range of applica- Center of Digital Dentistry
Peking University School and Hospital of Stomatology
tions, and casting a metal framework or baseplate can be 22 Zhongguancun Aveue South
added during fabrication to increase the strength of den- Haidian District, Beijing 100081
PR CHINA
tures for patients with minimal vertical dimensions or high Email: kqsyc@bjmu.edu.com
occlusal force (Fig. 5B). The FDM machine and PLA ma- Acknowledgments
terials used in this protocol are significantly less expensive The authors thank the firm and steadfast support of Beijing Baden Technology
than a milling machine and a milled blank. Furthermore, Company as the patent partner to make the market promotion.

the denture can be remounted onto an articulator to adjust Copyright © 2019 by the Editorial Council for The Journal of Prosthetic Dentistry.
the teeth while a milled denture cannot, and the rigid https://doi.org/10.1016/j.prosdent.2019.05.024

Deng et al THE JOURNAL OF PROSTHETIC DENTISTRY