EVALUATION OF THE EFFECT OF CPP-ACP ON THE MICROHARDNESS OF ENAMEL AFTER DENTAL BLEACHING: AN IN VITRO STUDY

Abstract

The present study aimed to evaluate the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on the microhardness of bovine enamel after dental bleaching with 35% hydrogen peroxide. This was an in vitro laboratory study conducted with 20 healthy bovine incisors randomly distributed into four experimental groups: control, dental bleaching, bleaching associated with a desensitizing agent based on potassium nitrate and sodium fluoride, and bleaching associated with CPP-ACP. Enamel microhardness was evaluated using a microhardness tester with a Knoop indenter at baseline, immediately after treatment, and at 7, 14, and 21 days after the experimental procedures. Data were subjected to statistical analysis using nonparametric tests, adopting a significance level of 5%. The results demonstrated a statistically significant difference over time only for the control group. The groups treated with desensitizing agent and CPP-ACP did not show statistically significant differences among the evaluated periods, suggesting relative stability of microhardness values throughout the experimental follow-up. It was concluded that both the desensitizing agent based on potassium nitrate and sodium fluoride and CPP-ACP showed similar behavior after dental bleaching, suggesting potential for maintaining enamel microhardness.