Tooth-color assessment after orthodontic treatment: a prospective clinical trial

Abstract

Introduction: Our aim was to prospectively assess in-vivo color alterations of natural teeth associated with fixed orthodontic treatment.

Methods: Twenty-six consecutive patients were treated with fixed appliances bonded with a chemically cured or a light-cured resin with a split-mouth design. The spectrophotometric data of a standardized labial circular area of all teeth were recorded, before bracket bonding and after debonding and cleaning procedures. The color parameters of the Commission Internationale de l'Eclairage-L∗, a∗, and b∗ (lightness, red/green, and blue/yellow)-were measured for each adhesive and type of tooth, and the corresponding color differences (ΔE) between the interval groups were calculated. The effect of these parameters on color was assessed with 3-way mixed analysis of variance (ANOVA) and the Bonferroni comparisons test (α <0.05).

Results: Orthodontic treatment was associated with changes in color parameters. The L∗ values decreased (P <0.001), whereas the a∗ and b∗ values increased (P <0.001) at the end of treatment. All measured types of teeth demonstrated significant color changes (ΔE); their mean differences ranged from 2.12 to 3.61 ΔE units. Chemically cured resin was associated with greater color changes than light-cured composite.

Conclusions: The color of natural teeth is changed in various ways after fixed orthodontic treatment.