The Effect of Casein Phosphopeptide-amorphous Calcium Phosphate after Bleaching on the Shear Bond Strength of Ceramic Brackets

Aims:To investigate the effect of postbleaching casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on the shear bond strength (SBS) of ceramic brackets.Materials and methods: This in vitro experiment was conducted on 27 healthy upper premolars that were randomly allocated to one of three groups (n = 9): the control group, the bleached group followed by casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP) treatment, and the bleached group followed by CPP-ACP treatment.All of the samples were instantly attached to ceramic brackets, soaked for 24 hours, and then debonded with a universal testing machine.The adhesive remnant index (ARI) was measured with a stereomicroscope to determine how much adhesive was left.SBS data were evaluated using one-way analysis of variance (ANOVA) followed by Tukey's test, while ARI index data were analyzed using Kruskal-Wallis and Mann-Whitney U tests with a significance level of 5%.Results: Analysis of variance analysis of the shear strength revealed a significant difference between the groups (p < 0.05) in the shear strength.A significant difference between the control and treatment groups was shown by post hoc Tukey (p < 0.05); however, there was no significant difference between the two treated groups (CPP-ACFP and CPP-ACP).Regarding the ARI, there were no notable differences across the groups (p > 0.05). Conclusion:Bleaching decreased the SBS of ceramic brackets bonded with glass ionomer cement.However, the CPP-ACFP and CPP-ACP were able to increase the SBS of ceramic brackets immediately after bleaching.Clinical significance: By applying CPP-ACFP and CPP-ACP to provide adequate SBS during orthodontic treatment, bonding of orthodontic brackets can be performed immediately following bleaching.