The effects of two 10% carbamide peroxide nightguard bleaching agents, with and without desensitizer, on enamel and sensitivity: an in vivo study.

OBJECTIVES: This study aimed to compare the effects of two 10% carbamide peroxide (CP) agents with or without desensitizers on tooth sensitivity, colour and enamel morphological changes. METHODS: Twenty subjects used a 10% carbamide peroxide gel with or without fluoride and potassium nitrate for 2 weeks. Sensitivity, spectrophotometric evaluation of colour and morphological analyses of replicas with scanning electron microscope (SEM) were performed before and after treatment. All data were analysed statistically. RESULTS: Both bleaching agents induced sensitivity; however, the 10% CP bleaching agent with fluoride and potassium nitrate produced significantly lower sensitivity (P < 0.05) than the bleaching product without desensitizing agents. In spectrophotometric evaluation, no difference in bleaching effectiveness was found between the tested bleaching gels, and the SEM analysis confirmed the absence of relevant alterations of the enamel surface in both groups. CONCLUSION: The use of 10% carbamide peroxide gel with fluoride and potassium nitrate reduced the incidence of sensitivity during the bleaching treatment compared to a bleaching agent that did not contain desensitizing agents. The bleaching effectiveness of the tested products was comparable.