Effect of Er:YAG laser versus chlorhexidine disinfection on dentin bond strength of two adhesive systems

Objective: This study evaluated the effects of ۲% chlorhexidine (CHX) and Er:YAG laser on the shear bond strength (SBS) of resin composite to affected dentin using two adhesive systems.Methods: Sixty extracted third molars were randomly assigned to three disinfection groups (control, ۲% CHX, and Er:YAG laser). Each disinfection group was further divided into two subgroups based on the adhesive system used (an etch-and-rinse or a universal self-etch system), yielding a total of six groups (n=۱۰). After caries excavation, dentin surfaces were treated according to the assigned disinfection and adhesive protocols. The resin composite was then applied to the treated surface using a cylindrical mold. Samples underwent ۱۰,۰۰۰ thermal cycles, followed by shear bond strength (SBS) testing and failure mode analysis. Data were analyzed using two-way ANOVA and chi-square test at the significance level of P < ۰.۰۵.Results: ANOVA revealed no significant differences in mean bond strength among the disinfection groups with either adhesive system (P > ۰.۰۵).  However, the etch-and-rinse adhesive showed significantly higher SBS compared to the universal self-etch adhesive across all disinfection groups (P < ۰.۰۵). Chi-square analysis revealed no significant differences in failure modes among the groups (P = ۰.۷۱).Conclusions: Disinfection of affected dentin with either Er:YAG laser or ۲% CHX does not reduce the bond strength of adhesive systems. The etch-and-rinse adhesive consistently achieved higher SBS than the universal adhesive after dentin disinfection, suggesting that it may be preferred for clinical use.

کلیدواژه ها:

Affected dentin ، Bond Strength ، Chlorhexidine ، disinfection ، Erbium ، Laser