Effect of Scanning Strategies on the Accuracy Metrics of Five Intraoral Scanners for Tooth-Supported Fixed Prostheses

This in vitro investigation assessed the influence of scanning strategy on digital impression accuracy of five intraoral scanners (IOSs) for tooth-supported fixed prostheses and determined the optimal strategy for each scanner.

A maxillary typodont model with abutment preparations was scanned using a high-precision extraoral scanner (Solutionix C500) to create a reference STL file. Five intraoral scanners (IOSs)-TRIOS 3, TRIOS 5, Aoralscan Elite, Medit i700/w, and Medit i900-were tested. A single operator performed 10 scans per IOS under standardized conditions, employing manufacturer-recommended (MR), scan lock (SL), or smart stitching (SS) scanning strategies based on software compatibility. Geomagic Control X, using best-fit alignment, evaluated the resulting STL files. Trueness and precision were quantified using root mean square (RMS) error, and statistical analysis involved one-way ANOVA and Duncan's post hoc test (α=.05).

Statistically significant differences in trueness and precision were identified among the intraoral scanners (IOSs) and scanning strategies (P < .01). The Aoralscan Elite consistently exhibited the highest level of accuracy, whereas the TRIOS 3 showed the greatest deviations within the MR and SL subgroups (P < .05). The influence of scanning strategy was significant for the Medit i700/w and Medit i900; however, no such effect was observed for the Aoralscan Elite or the TRIOS devices.

The scanning strategy significantly influenced the accuracy of the intraoral scanners (IOSs). Among all evaluated devices, the Aoralscan Elite exhibited the greatest trueness and precision.