3D analysis of rest seats in clinical environment

Introduction: rest seats are used in Removable Prosthodontics to provide indirect retention for the removable partial dentures and to transfer the forces through the long axis of the abutment tooth. Materials and methods: the rest seats were scanned with Dental Wings® Model DW-IO-001 Intraoral Scan (IOS) and were analyzed the bucco-lingual distance, the mesio-distal distance, thickness and angle formed by the occlusal support and the vertical part of the minor connector. Results: seventeen rest seats were observed and grouped according to teeth groups. Bucco-Lingual (BL) distance of the oclusal rest seats prepared present correct values, excluding canines. The Mesio-Distal (MD) distance is correctly done only in canines and superior premolars. In terms of thicknesses, no rest seat preparation was done according to the guidelines, being more shallow. Only the angle of the rest support surface with the tooth axial wall in inferior premolars was correctly done (<90º). Conclusions: the methodology used in this research to analyse the rest seat dimensions enables us to obtain results with high metric precision. Special care must be taken when supervising students in order to improve clinical results.