Effect of a Desensitizing Agent on Shear Bond Strength of Ceramic Bracket on Previously Bleached Teeth

Abstract

This study aims to analyze the effect of desensitizing agents on the shear bond strength (SBS) of ceramic brackets after in-office bleaching procedures. Twenty-seven extracted premolars were equally divided into three groups (n = 9). Group 1 served as the control; bleaching was performed with 37% hydrogen peroxide. In group 2, bleaching and the application of a fluoride-containing desensitizing agent (CPP-ACFP) were performed. In group 3, bleaching and the application of a non-fluoride-containing desensitizing agent (CPP-ACP) were performed. Ceramic brackets were bonded with composite resin. SBS was tested using a universal testing machine. The site of bonding failure was measured using the adhesive remnant index (ARI) score. There was a statistically significant difference in mean SBS values (p < 0.05). Group 1 showed the lowest SBS value (6.32 ± 4.83 MPa), which differed significantly with groups 2 and 3 (p < 0.05). There was no significant difference between group 2 (15.36 ± 4.67 MPa) and group 3 (12.19 ± 6.81 MPa) (p > 0.05). The ARI score did not show a significant difference. The conclusion is that the application of fluoride-containing and non-fluoride desensitizing agents increases the shear bond strength of ceramic brackets on bleached teeth with composite resin cementation. The application of both desensitizing agents had no impact on the results of the ARI score, with the highest ARI score in each group being 4, indicating that less than 10% of the adhesive substance remains on the enamel.