Manually Versus Digitally Fabricated Removable Partial Dentures

A Study on the Fit and Behaviour of Computer-aided Design and Rapid Prototyping Fabrication of Removable Partial Dentures

In the clinical trial, the Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) fabricated removable partial dentures (RPD's) are evaluated on casts and clinically compared with a traditional fabricated RPD for 50 consecutive patients. During 5 years the patients are in a follow-up program in order to judge long-term stability, loss of retention, fractures, … of both groups of dentures.

The classic removable partial denture (RPD) is a denture fabricated in CrCo using the "lost wax" technique. This hand-made way of working makes the final result vulnerable, not always predictable and not reproducible. Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) techniques have been introduced in dentistry, particularly to fabricate crowns and bridges (fixed partial dentures). There is little research in the field of removable partial framework fabrication. This may be in part be attributed to the lack of suitable dedicated software. In the technical part of the study, existing software and hardware is adjusted to maximize the automation in the application of computer-aided technologies to surveying of digital casts and pattern design and the subsequent production of sacrificial patterns using removable partial (RP) technologies. In the clinical trial the CAD/CAM fabricated RPD's are evaluated on casts and clinically and compared with a traditional fabricated RPD for 50 consecutive patients. For every patient, two RPDs are made in the same material (CrCo).The clinical parameters (fit, stability, retention, support, friction) are double blind evaluated by two dentists. At the end of the treatment, the patient can choose one of them. Both RPDs are fabricated in the same time frame for the fabrication of the "classic" RPD. There are for the patient no extra sessions scheduled. During 5 years the patients are in a follow-up program in order to judge long-term stability, loss of retention, fractures, … of both groups of dentures. Hypothesis1: CAD/CAM fabricated RPD's can meet the clinical standards for RPD's. Hypothesis 2: Dentists do not observe a difference between the classic and CAD/CAM fabricated RPD. Hypothesis 3: Patients do not see/feel any difference between the classic and CAD/CAM fabricated RPD.

group receiving Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM)fabricated removable partial dentures (double blind)

group receiving Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM)fabricated removable partial dentures (double blind)

After casting "fit of the framework" between two identical reomvable partial dentures (same design, looks, material...) fabricated in a different way.

There will be a placement of a removable partial denture, and after 3 to 5 days, this placement will be re-checked as a follow up.