Effects of Training on the Execution of Complete-Arch Scans. Part 2: Scanning Accuracy

Abstract

Purpose: To investigate the effect of training on scanning accuracy of complete arch scans (CAS) performed by first-time users, with a distinction made between specific training (repeated performance of CAS) and nonspecific training (simple use of an intraoral optical scanner for a sextant scan in the context of a CAD/CAM teaching module).

Materials and methods: A total of 36 students with no experience in intraoral scanning were randomized into three groups (n = 12 per group) according to the number of CAS sessions: three sessions (3S), two sessions (2S), and one session (1S). Each student had to perform 10 CAS per scanning session. Sessions were scheduled at T₀, T₁, and T₂ for group 3S; at T₀ and T₂ for group 2S; and at T₂ for group 1S. Before the final scanning session in each group (ie, the first scanning session in group 1S), the students completed a CAD/CAM teaching module, which included fabrication of a monolithic crown in a fully digital chairside workflow.

Results: In all groups, repeated CAS resulted in improved scanning accuracy. Participation in the CAD/CAM module had a positive effect on initial accuracy for CAS. Mean absolute deviations in cross-arch distance were 84 μm (T₀), 68 μm (T₁), and 63 μm (T₂) for group 3S; 79 μm (T₀) and 61 μm (T₂) for group 2S; and 67 μm (T₂) for group 1S.

Conclusion: To perform CAS with the best possible accuracy, specific training is highly recommended. In addition, nonspecific training leads to an improvement in initial scanning accuracy.