Visual Tooth Color Determination with Different Reference Scales as an Exercise in Dental Students' Education

Visual color determination (VCD) requires color competence and individual training. The aim of this study was to evaluate the deviations in students' VCD with two different reference scales. The research hypothesis was that none of the color references would provide a better result. Participants evaluated nine templates randomly using two reference scales (VITA-classical (VC) and 3D-Master-Toothguide (3DM_TG)). The color distance to the chosen color (ΔE_ab) was calculated in the CIELAB 2000. The sum's changes in the parameters (LCh°) represented the target variable. Results were evaluated with non-parametric, rank-scaled methods, utilizing the median with a 25%-75% quartile. The significance level (α = 0.05) is determined using the Student's t-test. The mean ± 95%CI (SD) was -1.27 ± -1.09 (3.18); the median ΔE₀₀ was -1.49 (-1.97; 0.96) for dC_{3DM_TG}. The determination with VC showed noticeable differences (dC_VC), with a mean ΔE₀₀ of 0.00 ± 0.00 (2.20) and a median ΔE₀₀ of 0.00 (1.17; 1.71). The standard error was 0.19 for the dC_VC and 0.27 for the dC_{3DM_TG}. dC_{3DM_TG} vs. dC_VC showed significant differences at p < 0.001. The dental student's VCD resulted in color deviations, regardless of the reference template used. The color deviations in hue and chroma were comparable, regardless of the reference scale. VCD's early implementation in dental education is useful to avoid shade misjudgments and potentially expensive remakes of dentures.