Accuracy of 3D scan data of extraorally digitized removable complete dentures with or without metal bases obtained with intraoral scanners

Abstract

Statement of problem: Studies of the accuracy of extraorally digitized removable complete dentures (RCDs) acquired with intraoral scanners (IOSs) are lacking. Purpose: The purpose of this in vitro study was to assess the trueness and precision of extraorally digitized RCDs with or without a metal base obtained with 3 IOSs. Material and methods: Three types of RCDs—a heat-polymerized resin-based maxillary (MxR group) and mandibular (MnR group) RCD, and a metal-based maxillary (MxM group) RCD—were fabricated. Three fiducial markers were attached to each RCD as reference points for scan alignment. Reference scan data were obtained by using an industrial scanner. Each RCD was extraorally scanned by using 3 IOSs: TRIOS 5, i900, and Primescan (n=10). Scan data were aligned with the reference by using 3-point and best-fit alignment methods. Trueness was assessed by using mean absolute deviation (mAD) and root mean square deviation (RMSD), while precision was determined by the standard deviation (SD) of mADs (SDmAD) and the SD of the means of original deviations (SDmOD). Statistical analyses included the Kruskal–Wallis test for trueness and Levene test for precision (α=.05). Results: In the MxR group, TRIOS 5 demonstrated significantly better trueness (P<.001). In the MxM group, mAD analysis found no significant differences (P=.532), whereas RMSD analysis showed better trueness for i900 compared with Primescan (P=.002). In the MnR group, mAD differences were not significant (P=.289), but RMSD analysis indicated TRIOS 5 outperformed Primescan (P<.001). For precision, TRIOS 5 exhibited significantly lower SDmAD in the MxR group compared to i900 (P<.001), though SDmOD differences were not significant (P=.055). Precision for the MxM group did not significantly differ among groups based on SDmAD (P=.496) and SDmOD (P=.239). In the MnR group, SDmAD differences were not significant (P=.094), but SDmOD analysis showed TRIOS 5 had significantly better precision (P=.007 versus i900; P=.005 versus Primescan). Conclusions: TRIOS 5 demonstrated superior or comparable performance in both trueness and precision across all tested conditions. i900 and Primescan exhibited variable performance under specific conditions but produced clinically acceptable results in terms of trueness and precision. © 2025 Editorial Council for The Journal of Prosthetic Dentistry