In vitro study of the accuracy and efficiency of wireless intraoral scanners at various battery levels

Objectives: To determine the trueness and precision of 2 wireless intraoral scanners (IOSs) under various battery levels, and assess scanning efficiency.Methods: A maxillary cast with 4 metal spheres attached was fabricated. Two wireless IOSs (TRIOS 3 and TRIOS 4) were evaluated under 3 battery levels (1-30%, 31-60%, and 61-100%; n = 30). Six horizontal distances and 1 vertical distance were measured between 4 spherical centers and 1 generated plane. The distance deviations were determined with a coordinate-measuring machine data set. Kruskal-Wallis and Levene tests were used to analyze trueness and precision. Scan time and the number of three-dimensional (3D) images captured were analyzed by using a 2-way analysis of variance.Results: In terms of trueness and precision, no significant differences were found at various battery levels over the majority of the measured distances. TRIOS 4 demonstrated better trueness than TRIOS 3 for cross-arch scan. The 61-100% battery level resulted in the shortest scan time and the least number of 3D images captured (p < 0.001). Scan time and number of 3D images captured were strongly correlated for TRIOS 3 (r = 0.66) and TRIOS 4 (r = 0.89).Conclusions: Changes in battery level had no impact on the trueness and precision of TRIOS 3 and TRIOS 4. High battery level IOSs resulted in faster scans and fewer 3D images captured with less storage space. TRIOS 4 scanned faster, captured fewer images, and demonstrated better trueness than TRIOS 3. Clinical significance: Although all battery levels of wireless IOSs provide comparable trueness and precision, a wireless IOS with a high battery level is more time efficient than one with a low battery level in complete-arch scan.