Effects of carbamide peroxide containing bleaching agents on the morphology and subsurface hardness of enamel

The purpose of this study is to evaluate the effects of nightguard bleaching agents (Karisma and Yotuel) on the enamel surface of forty anterior teeth. Ten teeth of each group were evaluated with SEM and ten teeth of each group were tested with a microhardness tester Morphologic alterations were observed on the enamel surfaces with SEM. Karisma group showed a significant decrease in enamel hardness (p<0.05) and microhardness values of enamel were increased significantly in Yotuel group (p<0.05).