Objective: To evaluate the influence of fluoride varnish and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on bleached enamel microhardness. Materials and Methods: Thirty human permanent incisors were selected to preparer thirty enamel specimens. All specimens were bleached using 40% hydrogen peroxide bleaching agent (power whiting YF). The bleached enamel samples were divided into three equal groups (n = 10) according to the used remineralizing agent. Group A was treated by CPP-ACP past (GC Tooth mousse), group B was treated by Fl varnish (Biflourid 10) and group C was stored in artificial saliva. The microhardness was assessed using Vicker test (before bleaching, after bleaching and after application of different remineralizing agents). The data was collected and statistically analyze using two-way ANOVA and post hock LSD test at (P< 0.05).
Results: Enamel microhardness has diminished significantly in all groups after bleaching. After application of remineralizing agents, there was a significant increase in microhardness. There was no significant difference between groups A and B, while there was significant difference between these groups and group C. Conclusions: Using Bifluoride 10 , CPP-ACP or artificial saliva improves bleached enamel microhardness.