Digital Complete Dentures

Computer-aided design and computer-aided manufacturing (CAD-CAM) technology has been successfully used for the fabrication of fixed prostheses for the last two decades.⁴ However, the application of this technology to the fabrication of removable complete dentures has only recently come to light.⁴ The first attempt at fabricating a computer-aided-designed-computer-aided-manufactured (CAD-CAM) complete removable dental prosthesis was initiated by Maeda et al. in 1994,⁶ however, a detailed overview of the technique and concept was not available until 2012.⁷

Initially, digital dentures were considerably more expensive to fabricate than conventional complete dentures.^8-10 This was in part associated with the closed format of the digital denture fabrication process; there were very few systems/manufacturers available, and it was imperative to buy the trays, materials, and equipment compatible with that system as well as fabricate the prostheses through the specific manufacturer (closed system). Since the last decade, there have been several advances in the technology of digital denture fabrication, a rapid increase in the number of providers, and the development of open digital systems. These systems also permit the in-house fabrication of digital dentures when the milling machines/printers are available in dental clinics.¹¹

Digital dentures are suitable for all skeletal relationships.¹² Digital complete dentures have superior material properties and several studies have reported very high levels of patient satisfaction with them.¹³ The advantages and disadvantages of digital dentures are listed below:

Advantages:¹

1. Fewer clinical visits:^1,13 The fabrication of digital complete dental prostheses requires a fewer number of clinical steps compared to conventional complete dentures; It is possible to record all the clinical information in one appointment and place the CAD-CAM dentures at the next appointment.

2. Simplified and reduced laboratory steps: The laboratory procedures are greatly reduced and simplified as the arduous task of teeth setting and denture processing are accomplished with CAD-CAM technology.^1,13,14

3. Superior retention and fit: Digital complete dentures are reported to have superior retention and fit compared to conventional complete dentures due to minimal fabrication distortion.¹⁵

4. Lower incidence of sore spots: As the digital dentures are milled from a prepolymerized block of acrylic resin, there is reduced polymerization shrinkage and a lower incidence of sore spots and microbial colonization.¹⁶

5. Superior physical and mechanical properties: Digital complete dentures are reported to have superior physical and mechanical properties compared to conventional complete dental prostheses thereby permitting the fabrication of digital denture bases with a reduced thickness.^14,15

6. Minimal denture tooth movement: Digital fabrication results in minimal denture tooth movement thereby decreasing the need for repeated occlusal adjustments.¹⁷

7. Try-in: Digital technology can be used to print a trial prosthesis that can be used to evaluate the aesthetic and function prior to its finalization.¹

8. Rapid fabrication of a spare/new prosthesis: Fabrication of digital prostheses helps generate a repository of digital data which enables rapid fabrication of a spare or new prosthesis, without any clinical appointments.¹⁴ This reproducibility is particularly helpful for patients who are medically debilitated and cannot visit the dental office. The new replacement denture will have the exact form as the previous denture thereby facilitating quick patient adaptation.

9. Cost: The cost of a digital complete dental prosthesis eventually turns out to be less than the cost of a conventional acrylic complete dental prosthesis as the number of clinical appointments and laboratory procedures are significantly reduced.^4,13,15

10. Standardization and quality control: Digital dentures may permit improved standardization in clinical research and quality control on complete dentures as well as implant-retained overdentures.

Disdvantages:

1. Specialized clinical training required: Fabrication of digital complete dental prostheses requires specialized clinical training and there is a learning curve attached to it.¹⁴

2. Time: Dental practitioners need to invest considerable time in the planning, laboratory communication, and execution of digital complete dental prostheses.¹⁴ However, experience with this new technology may help speed up these procedures.

3. Compromised esthetics: When the try-in procedure is eliminated, it precludes the assessment of the esthetics, phonetics, and occlusion prior to the fabrication of the definitive prostheses. This may result in patient dissatisfaction and failure of the treatment rendered.¹³

4. Bond between the artificial teeth and the denture base: There is a concern regarding the bond between the artificial teeth and the prepolymerized denture base being sub-optimal.¹⁸ Milling/printing the denture as a single unit (along with the artificial teeth) helps circumvent this problem.¹⁹