Digital Complete Dentures

Keywords :

Denture, Complete, Computer-Aided Design, Printing, Three-Dimensional, milling.

CITATIONS :

Shah N. Digital Complete Dentures. J Prosthodont Dent Material 2022;3(2):1-2.

Edentulism can reduce the quality of life associated with dental health by affecting appearance, phonation, and function that can be restored by placing new removable dentures. The purposes of each technique of complete denture fabrication are to provide prosthesis with ultimate mucosal adaptability and reduce processing error resulting in good retention, support, and stability.
Conventional complete denture fabrication has been reliable for decades. However, the clinical protocols involved in the production of a conventional complete denture may be complicated, time-consuming, and difficult to control quality from the laboratory process.
Adopting digital technologies for complete denture prosthesis has been more difficult, with capturing edentulous impressions and multistep laboratory procedures. Capturing the resiliency of supporting tissues of complete dentures is most challenging. For this reason the semi-digital
CAD CAM (Computer-Aided Design & Computer-Aided Manufacturing) complete dentures were first described in 1946 and now represent an improvement over conventional denture production.1 Reduced chair time, decreased number of patient visits, and simplification of the laboratory process, duplication of complete denture, ease of storage of data are benefits of denture fabrication using CAD-CAM. CAD-CAM produces fewer errors during the denture making process and can allow the efficient fabrication of a replacement prostheses based on stored data. In addition, radiologic or surgical templates can be easily produced by using data retrieved from the patient. This is highly helpful for elderly people who have underlying diseases and having difficulty to come to dental office.²
The fabrication of complete dentures by CAD-CAM methods has become popular in both clinical and laboratory practices in recent years. This increased popularity may be attributed to the improvements in the CAD-CAM techniques and the growing awareness of dental practitioners and laboratory technicians, along with an increasing flexibility of combining the conventional clinical and digital laboratory workflow.²
There are three processes in CAD/CAM workflow. Data collection and CAD are the first two steps in the process. The last step, CAM process, can be done using either additive manufacturing (threedimensional [3D] printing) or subtractive manufacturing (milling). A computerized numeri control subtractive milling process and a system of rapid prototyping (RP) that is commonly known as 3D printing, an additive manufacturing process, are available to fabricate CAD-CAM complete dentures.³
The milling approach is a method of fabricating dentures by removing materials from repolymerized PMMA (Polymethyl methacrylate) block to form the desirable shape. Milled dentures possess superior mechanical qualities over conventional complete dentures due to the absence of polymerized shrinkage resulting in better retention. The residual monomer content of PMMA block is lower than that of heat polymerized PMMA because the block was completely polymerized in a high-pressure condition.
The principal disadvantage of milling is the waste product, as a large portion of the block is left unused and wasted during the process. Moreover, milling technique has certain limitations such as the contour of the restoration relies on the size of cutting tools. If the diameter of the cutting tool is bigger than the diameter of certain components, the internal fit accuracy will be compromised, or the marginal qualities will be degraded.33D-printing technique using direct light processing is the most extensively used in dentistry, for example, 3D-printed casts potentially replace conventional stone casts with clinically acceptable accuracy. Complete dentures fabricated using the RP (rapid prototyping) technique have also elicited patient satisfaction comparable with that for conventional complete dentures. RP has been further used in complete denture fabrication for the precise reproduction of denture bases and printed wax patterns. Both workflows have been reported to provide a clinically acceptable accuracy which is greater than that of conventional denture processing techniques.⁴
Complete denture fabrication through digital technology seems to be versatile, enabling the combination of the well-documented traditional technique in clinical practice with the latest CAD/CAM breakthroughs in the laboratory setting. The new digital technology provides new and promising opportunities and a way to bring the dental profession in the next level. Nevertheless, this path should not be taken without consideration and careful planning.

REFERENCES :

1. Zupancic Cepic L, Gruber R, Eder J, Vaskovich T, Schmid-Schwap M, Kundi M. Digital versus Conventional Dentures: A Prospective, Randomized Cross-Over Study on Clinical Efficiency and Patient Satisfaction. J Clin Med. 2023 Jan 5;12(2):434.
2. Charoenphol K, Peampring C. Fit Accuracy of Complete Denture Base Fabricated by CAD/CAM Milling and 3D-Printing Methods. Eur J Dent. 2022 Dec 13.
3. Grande F, Tesini F, Pozzan MC, Zamperoli EM, Carossa M, Catapano S. Comparison of the Accuracy between Denture Bases Produced by Subtractive and Additive Manufacturing Methods: A Pilot Study. Prosthesis. 2022; 4(2):151-159.
4. Yoshidome K, Torii M, Kawamura N, Shimpo H, Ohkubo C. Trueness and fitting accuracy of maxillary 3D printed complete dentures. J Prosthodont Res. 2021 Oct 15;65(4):559-564.