Effect of Home Bleaching Agents Containing 10% Carbamide Peroxide and 7.5% Hydrogen Peroxide on the Microhardness of Sound Human Dentin
Authors: Maurício Costa Silveira de Avila, Robson Tetsuo Sasaki and Roberta Tarkany Basting
Abstract: Purpose: Assess the effect of home bleaching agents containing 10% carbamide peroxide and 7.5% hydrogen peroxide, on the microhardness of sound human dentin. Methods: The materials Poladay (7.5% hydrogen peroxide) and Platinum (10% carbamide peroxide) were applied to fragments of human dentin (n=10) for 1 hour daily, and during the remainder of the time, they were kept in artificial saliva in individual containers. The control group was constituted of dentin fragments that remained in an artificial saliva solution throughout the entire experiment. Microhardness tests were performed at the following times: initial (baseline), 21 days of bleaching and 14 days after the end of treatment. Results: The analysis of variance (ANOVA) followed by the Tukey test showed that the dentin microhardness for the treatment agents Poladay and the control group presented no statistically significant differences at the analyzed times. For the Platinum group, there was a significant increase in dentin microhardness as a function of time. There was no difference in microhardness at the baseline time among the 3 studied groups, but at the time of 21 days after bleaching, the dentin treated with Platinum presented significantly higher microhardness values than the other groups. At the 14 days post treatment time, Platinum and the control group presented statistically similar microhardness values, while the Poladay group presented the lowest values. Clinical significance: The bleaching agent Platinum allowed an increase in dentin microhardness after 21 days of use, while Poladay led to no alterations in the studied times.