Do ambient lighting conditions affect the accuracy of implant position capture for complete arch prostheses using intraoral photogrammetry?

Abstract

Statement of problem Ambient lighting conditions have been reported to affect the accuracy of intraoral scans. Nevertheless, the influence of these conditions on the accuracy of scans with intraoral photogrammetry (PG) has not been previously analyzed. Purpose The purpose of this in vitro study was to assess the influence of light intensity on the accuracy (trueness and precision) of complete arch implant scans captured by using an intraoral PG system and recorded by an intraoral scanner (Aoralscan Elite; Shining 3D), which allowed the recording of both soft tissues and 3-dimensional (3D) implant position. Material and methods An edentulous mandibular stone cast with 6 implant abutment analogs was used as the master model. Five groups based on light intensity were determined (100, 500, 1000, 5000, 10 000 lux). Each group was scanned a total of 20 times (n=20), resulting in a total of 100 digital scans (N=100). For the scan acquisition, an IOS including intraoral PG technology (Aoralscan Elite; Shining 3D) was used. Linear and angular deviations were calculated by comparing the digital scans with the reference data from coordinate measuring machine measurements of the master model. (CMM). The Shapiro-Wilk, 1-way ANOVA (Welch), post hoc Tukey, and Levene tests were used to analyze the differences among the groups in terms of trueness and precision (α=.05). Results For linear deviations, the lowest deviations in trueness were reported in the group 10 000 lux (0.019 mm), showing statistically significant differences from the groups 100 lux (0.027 mm) (P=.022) and 1000 lux (0.025 mm) (P=.002). For angular deviations, the lowest deviations in trueness were reported for the groups 500 (0.053 degrees), 5000 (0.054 degrees), and 10000 lux (0.046 degrees). Statistically significant differences appeared between these groups (500, 5000, and 10000 lux) and the group 1000 lux (0.086 degrees) (P<.001 in all comparisons), which reported the worst values. No differences in precision were reported for either linear (P=.334) or angular (P=.689) deviations. Conclusions Different ambient lighting conditions affected the trueness of the intraoral PG system tested, but not the precision. The magnitude of the differences reported among the groups could be deemed negligible.