Efficacy, longevity, and bleaching sensitivity of carbamide and hydrogen peroxides for in-office bleaching: A 6-month randomized, double blind, split-mouth clinical trial.

PURPOSE

To evaluate the efficacy, longevity, and bleaching sensitivity of in-office bleaching with 37% carbamide (CP) and 35% hydrogen peroxides (HP).

METHODS

45 volunteers were enrolled in this randomized, double blind, controlled, split-mouth clinical trial with a 6-month follow-up. Left and right hemiarches were randomly selected to receive CP or HP in-office bleaching. Three 40-minute applications of both bleaching agents were performed once a week at the same time. Tooth shade and bleaching sensitivity were recorded before and after bleaching sessions, 1 to 7 days after bleaching sessions and up to 6 months after the last bleaching session using, respectively, a shade guide and Visual Analogue Scale (VAS). Color change, global immediate sensitivity - GIS (sum of sensitivity levels reported during three bleaching sessions), trans- and post-bleaching sensitivity were obtained and analyzed using paired Student t-test and two-way ANOVA/Tukey post-hoc tests (P< 0.05).

RESULTS

HP had statistically higher global immediate sensitivity than CP. CP showed statistically lower sensitivity levels during bleaching sessions and in two subsequent days than HP. CP and HP provided statistically similar tooth shade at the end of the last bleaching session and 3 and 6 months after the last bleaching session.

CLINICAL SIGNIFICANCE

In-office tooth bleaching using CP resulted in less bleaching sensitivity than HP, without compromising efficacy and longevity over a 6-month follow-up period. The use of 37% carbamide peroxide in substitution for 35% hydrogen peroxide can promote an effective, long-lasting, and more comfortable in-office tooth bleaching for patients.