Effect of scan path on accuracy of complete arch intraoral scan

Purpose: This study aimed to compare the accuracy of an alternative scan path with that of traditional scan paths to obtain a more accurate method for complete arch scans.

Materials and methods: A mandibular stone cast, including tooth preparations for the inlay, crown, and fixed prosthesis, was scanned 10 times using four different scan paths (A, B, C, and D). The scans were converted into stereolithography files, resized, and superimposed onto a control file obtained from a desktop scanner. The scan time, total surface deviation, and local deviation of the mandibular teeth were measured. One-way analysis of variance (ANOVA) and Welch ANOVA were used for statistical analyses (α = .05). The relative standard deviation and standard error of the mean were calculated to evaluate accuracy.

Results: The total surface deviation differed significantly according to the scanning path despite a similar scan time. Path D had the highest accuracy and the most uniform color maps, showing minimal deformation of the digital model. Meanwhile, no significant differences were found in the local deviations in the individual tooth assessments, likely owing to issues with the superimposition method.

Conclusion: Among all scan paths, the scan path with the shortest distance from the starting point to the end point showed the smallest total surface deviation and the highest accuracy. No differences were observed in the deviations of specific teeth based on the scan path.