Bonding properties of newly erupted and mature premolars

Introduction: The purpose of this study was to determine whether there were differences in bond strength between mature and newly erupted teeth when using both conventional and self-etching primer techniques for bonding orthodontic appliances. The nature of adhesive bond failure among the groups was also compared by using the adhesive remnant index (ARI). Methods: Premolars were collected, randomly divided, and bonded with either the conventional or the self-etching technique. Brackets were debonded on a testing machine with a shear-testing device. Bond strengths were compared with ANOVA and the Weibull analysis. Results: There were no statistically significant differences in bond strength values between the conventional etching and the self-etching primer groups or between newly erupted and mature teeth. ARI scores differed between mature and newly erupted teeth. Newly erupted teeth had more adhesive failures, and mature teeth had more cohesive bond failures at the enamel-composite resin interface. Conclusions: Based on these results, bond strength does not appear to be affected by the posteruptive enamel maturation process.