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Updated: Oct 20, 2025

Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision
Published on: April 29, 2014
Effect of different arch widths on the accuracy of three intraoral scanners
Narin Kaewbuasa1, Chakree Ongthiemsak1
1Department of Prosthetic Dentistry, Faculty of Dentistry, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
Purpose:
The purpose of this study was to compare the accuracy of three intraoral scanner (IOS) systems with three different dental arch widths.
Materials And Methods:
Three dental models with different intermolar widths (small, medium, and large) were attached to metal bars of different lengths (30, 40, and 50 mm). The bars were measured with a coordinate measuring machine and used as references. Three IOSs were compared: TRIOS 3 (TRI), True Definition (TD), and Dental Wings (DW). The relative length and angular deviation of both ends of the metal bars from the scan data set (n = 15) were calculated and analyzed.
Results:
Comparing among scanners in terms of trueness, the relative length deviation of DW in the small (1.28%) and medium (1.08%) arches were significantly higher than TRI (0.46% and 0.48%) and TD (0.33% and 0.18%). The angular deviation of DW in the small (1.75°) and medium (1.83°) arches were also significantly greater than TRI (0.63° and 0.40°) and TD (0.55° and 0.89°). Comparing within scanner, the large arch of DW showed better accuracy than other arch sizes (P < .05). On the other hand, the larger arch of TD presented a greater tendency of angular deviation in terms of trueness. No significant differences were found in terms of trueness between the arch widths of TRI group.
Conclusion:
The different widths of the dental arches can affect the accuracy of some intraoral scanners in full arch scan.

