Comparison of the accuracy of removable partial denture frameworks fabricated using conventional and digital impressions: a clinical study

Abstract

Purpose. Removable partial dentures (RPDs) require metal frameworks for support, stability, and retention. Conventional impression methods are time-consuming and may introduce inaccuracies that affect framework fit. Intraoral scanning (IOS) offers a digital alternative that may improve accuracy and efficiency; however, few studies have quantitatively compared frameworks fabricated using IOS data with those fabricated using conventional methods. This study aimed to compare the accuracy of RPD frameworks fabricated using conventional and IOS-based methods. Materials and methods. This study included 15 arches from 13 patients requiring RPDs. Each arch received two metal frameworks, one fabricated using the conventional impression method (CON group) and the other using IOS (IOS group). Qualitative evaluations included visual inspection and pressing with a plugger, whereas quantitative evaluations were performed using three-dimensional superimposition and gap measurements at the rest-seat areas. Paired t-tests were used to compare the accuracy, and two-way analysis of variance was used to evaluate the interaction between the fabrication method and tooth position. Results. All frameworks met the qualitative evaluation criteria. In the quantitative evaluation, the IOS group exhibited a significantly smaller mean gap (201 ± 78 µm) than the CON group (239 ± 83 µm) (P = .015). Furthermore, the IOS group demonstrated significantly greater accuracy, particularly at the terminal abutments of distal-extension RPDs. Conclusion. Clinically acceptable RPD framework accuracy was achieved in both groups. However, accuracy was significantly better in the IOS group, especially at the terminal abutments of distal-extension RPDs.