Evaluation of the accuracy of different digital scanning systems and intraoral scanning strategies: An in vitro study

Abstract

Abstract Introduction: Differentiating between the various available digital impression systems in terms of accuracy could help in determining the most appropriate system to be used. Aim: The purpose of this in vitro study was to evaluate the accuracy of four different intraoral scanners, along with different intraoral scanning strategies (IOSs), and using the conventional impression method. Materials and Methods: A model with prepared teeth was scanned with a laboratory scanner. Following that, the model was scanned using the following four intraoral scanners (IOSs): TRIOS, CEREC AC Omnicam, Medit i700, and iTero Element 2. Three scanning strategies were used with each scanner during the intraoral scanning (C-motion, zig-zag, and wiggling strategies). Each strategy was repeated eight times resulting in 96 scans, along with eight conventional impressions. All three-dimensional test models were compared with the master model using Geomagic Control X. The master model was trimmed to isolate the teeth and was superimposed with all 104 test models. The data was statistically analyzed using the nonparametrical Kruskal–Wallis test. Results: Statistically significant differences were found when comparing all groups (the four IOSs and the conventional impression method) in terms of trueness and precision (P < 0.001). For trueness, the i700 was the highest ranked IOS (35.68 ± 1.18 μm), excelling in all groups regardless of the strategy used. For precision results, the best IOS was the i700 (46.14 ± 1.43 μm) regardless of the strategy used. Conclusion: Medit’s i700 scanner exhibited better accuracy compared to the other three scanners. Meanwhile, the zig-zag strategy may provide the best scanning accuracy when used with the majority of the scanners.