Influence of different bonding agents on the color stability of enamel after orthodontic bracket removal

Objective: This study aimed to assess the staining susceptibility of the hybrid layer remaining on the enamel surface after bracket removal, focusing on various bonding agents applied for the bonding process.Methods: A total of ۱۲۰ enamel discs were obtained from bovine incisors. The specimens were divided into ۵ groups (n=۲۴) according to the bonding agent applied, as follows: Group ۱: Control, Group ۲: Transbond XT, Group ۳: Proseal, Group ۴: Icon + Transbond XT, and Group ۵: Icon + Heliobond. After composite removal, half of the specimens were exposed to a tea solution and the other half to a tea + citric acid solution (n=۱۲). The “L”, “a”, and “b” color components were spectrophotometrically assessed at various stages including pre-bonding (T۱), after debonding (T۲), and after ۲۴-hour immersion in the discoloration solution (T۳). The color changes (ΔL, Δa, Δb) were analyzed by a two-way ANOVA at P<۰.۰۵.Results: In all groups, a small shift in all color components was observed after debonding and polishing the surface. All groups showed similar, noticeable color changes after exposure to the discoloration solutions. Neither the type of bonding agent nor the type of staining solution had a significant influence on ΔL, Δa, and Δb values between different treatment stages (P>۰.۰۵ for all comparisons).Conclusions: Despite enamel polishing, some discolorations remain on the enamel after debonding, possibly due to the primers applied during bracket bonding. The type of bonding agent and the staining solution does not significantly affect the color stability of teeth after debonding.

Keywords:

Bis-GMA , bonding agent , Debonding , orthodontic treatment , Staining , Tooth discoloration