Digital Technique for Removable Partial Denture (RPD) Frameworks

A study published in the Journal of Prosthetic Dentistry suggests that the digital technique for Removable Partial Denture (RPD) frameworks is accurate.

Removable partial dentures (RPDs) are traditionally made by casting, a complex, error-prone, and time-consuming process. Computer-aided design and computer-aided manufacturing (CAD-CAM) RPD systems may simplify the clinical steps and minimize errors; however, the accuracy of CAD-CAM RPD systems is unclear.

A team of researchers conducted a study to determine whether CAD-CAM systems are accurate for the manufacturing of Removable Partial Denture (RPD) frameworks.

A literature search was conducted through Medline-PubMed, Scopus, Lilacs, Web of Science, and Cochrane Library databases using specific keywords for articles published up to November 2019. Three reviewers obtained data and compared the results. All studies evaluated the framework accuracy or fit of prostheses fabricated with conventional and digital techniques.

Results of the Study

• A total of 7 articles, 2 clinical studies, and 5 in vitro studies that complied with the inclusion criteria were evaluated.
• One in vitro study compared indirect (extraoral) and direct (intraoral) scanning for partially edentulous ridges and shows that digital scans were better than conventional impressions in terms of trueness.
• In the other studies included, although the frameworks analyzed had clinically acceptable discrepancies (<311 μm), the material influenced the fit.
• Polyetheretherketone (PEEK) showed better fit than traditional metal cast RPDs. Co-Cr alloy RPDs produced by rapid prototyping exhibited the highest discrepancies when produced by sintering laser melting.

Thus, the researchers concluded that the digital technique for RPD frameworks is accurate. In the studies included, the analyzed frameworks had clinically acceptable gaps, but the results were heterogeneous among studies because the articles used different measurement methods with small sample sizes. Few studies discussed the long-term clinical performance. The digital technique for Removable Partial Denture (RPD) frameworks was accurate because the misfits and mismatches found in in vitro and clinical studies were within the acceptable clinical limit for RPDs.

Reference

Accuracy of CAD-CAM systems for removable partial denture framework fabrication: A systematic review by Ana Larisse Carneiro Pereira et al published in The Journal of Prosthetic Dentistry

https://doi.org/10.1016/j.prosdent.2020.01.003