The Effect of Gingival Color on the Accuracy of Different Intraoral Scanners in Partially Edentulous Patients: An In Vitro Study

Objective: This in vitro study evaluated the accuracy and precision of five intraoral scanners (IOSs) by examining the interaction between gingival model color and linear measurement distances. Materials and Methods: Seven color-distinct models were scanned to obtain absolute deviation data from six linear distances between four reference points. Measurements were analyzed using Zeiss Inspect software v2025.3.3.4. Due to non-normal data distribution, all factors (Scanner, Model, Pair) and their interactions were assessed using Aligned Rank Transform (ART) ANOVA. Accuracy was defined as median absolute deviation, and precision as the coefficient of variation (CV%). Results: Statistical analysis identified significant differences in absolute deviation across all main factors and their three-way interactions (p < 0.001). The Medit i700 and Trios 5 demonstrated the lowest overall median deviation (0.09 mm), followed closely by Trios 3 (0.10 mm), with no statistically significant differences among them. The P5 model yielded lower deviations, while extreme colors increased variability. In terms of precision, values varied significantly based on specific interactions; the highest precision was recorded for the Shining scanner on the White model (A–C pair, CV: 7.33%), whereas the lowest precision was observed for the Sirios scanner on the Black model (A–D pair, CV: 158.10%). Conclusions: Within the limitations of this in vitro study, deviation values varied according to gingival color and pair distance. Gingival colors with a higher pink saturation (P5) and shorter distances yielded lower deviations, whereas extreme colors and longer distances were associated with reduced precision.