Comparison of Tooth Color and Enamel and Dentinal Thickness between Orthodontically Treated and Untreated Individuals

This study compared tooth color and enamel and dentinal thickness between orthodontically treated and untreated individuals. (1) Methods: A matched case–control study was conducted. The sample included 26 patients who had received orthodontic treatment and 31 matched controls. The color assessment was performed subjectively using the VITA 3D-Master (VM) shade guide and objectively using the VITA Easyshade (VE) spectrophotometer. Differences in L*, a*, and b* (lightness, red/green, and blue/yellow) were calculated. The color change was evaluated using ΔE*ab and the whiteness index (WID). Tooth structure thickness (labiolingual, labial enamel, and labial dentin) was evaluated using cone-beam computerized tomography. The correlations between overall tooth color and tooth structure thickness were evaluated. (2) Results: A total of 228 teeth were evaluated. Color assessment using VM showed significant differences between orthodontically treated and untreated teeth (p < 0.001), while VE revealed no significant differences. Both groups showed no difference in tooth enamel and dentinal thickness. Significant differences in tooth color (p < 0.05) were observed between genders. Both VM and VE showed weak to moderate correlations with tooth color and enamel and dentinal thickness (p < 0.05). (3) Conclusions: Orthodontic treatment may demonstrate visually perceptible but acceptable and clinically undetectable tooth color alteration.