Effect of a carbamide peroxide bleaching gel containing calcium or fluoride on human enamel surface microhardness

摘要

This in vitro study evaluated the surface microhardness of human enamel submitted to bleaching with 10% carbamide peroxide (CP) containing calcium or fluoride. Ninety-eight dental blocks (5 x 5 mm2) with polished enamel surfaces were randomly assigned to 7 treatment groups (n=14), as follows: without bleaching and storage in artificial saliva (control); 10% CP; 10% CP + 0.05% calcium; 10% CP + 0.1% calcium; 10% CP + 0.2% calcium; 10% CP + 0.2% fluoride; and 10% CP + 0.5% fluoride. During 14 days, enamel surfaces were daily exposed to a 6-h bleaching regimen followed by storage in artificial saliva. Surface microhardness was measured before (baseline), during (7th day), immediately after bleaching (14th day) and 1 week post bleaching. Data were analyzed by two-way ANOVA and Tukey's test (p