Dental measurement procedure based on 3D analysis and data processing

This paper introduces a novel methodology for the alignment and comparison of 3D digital models of individual dental pieces, aimed at evaluating proficiency in the manipulation of rotary cutting instruments within the discipline of prosthetic preparations and conservative dentistry. The proposed approach comprises three principal stages: precise alignment of the 3D model utilizing a customized reference base, application of a parametric deformable model to transform the non-periodically sampled point cloud into a continuous and regular mesh, and quantitative analysis between pairs of modeled dental pieces. The methodology has been validated through the analysis of dental specimens fabricated from Duroplastic® and digitized using the Aidite® A-IS Pro desktop 3D dental scanner. The results demonstrated a high degree of precision in both alignment and modeling, with mean discrepancies between scans ranging from 0.0008 mm to 0.0165 mm, and maximum errors not exceeding 0.1416 mm across the entire surface of each tooth. The findings indicate that the proposed methodology possesses sufficient accuracy for facilitating comparisons between 3D point clouds from dental scans, thereby enabling its prospective application within the AIDDA® (Automated International Dental Dexterity Algorithm) system for the objective assessment of dental preparations. This approach permits precise comparisons between teeth carved by instructors and those prepared by students, thereby facilitating automated evaluations of student performance and progress in restorative dentistry competencies. Beyond its educational value, the AIDDA algorithm offers versatile potential for clinical and forensic applications in multiple dental specialties.