163COMPARATIVE EVALUATION OF THREE DIFFERENT REMINERALIZING AGENTS ON BLEACHED ENAMEL - AN IN-VITRO SEM AND MICROHARDNESS STUDYThe aim and objectives of this in-vitro study is to compare and evaluate the three different remineralizing agent on bleached enamel surface. Sixty freshly extracted maxillary incisors were selected. Each tooth was transversally sectioned positioned in a plastic mold and embedded using a self cure acrylic resin. The enamel surfaces were ground into flat surface using silicon carbide paper. GROUP A (n=20) stored in artificial saliva as control group. GROUP B (n=20) Bleaching with 35% Hydrogen peroxide gel and combinations of with 35% hydrogen peroxide gel and clinpro tooth cream, reminpro tooth cream and GC Tooth Mousse Plus and stored in artificial saliva and grouped as B1,B2,B3,B4 respectively. GROUP C ( n=20) Bleaching with 40% Hydrogen peroxide gel and combinations of with 35% hydrogen peroxide gel and clinpro tooth cream, reminpro tooth cream and GC Tooth Mousse Plus and stored in artificial saliva and grouped as C1,C2,C3,C4 respectively. Following bleaching the remineralizing agents were applied and stored in artificial saliva and the application was repeated in 7,14& 21 days interval. The samples were tested for micro hardness and surface morphological changes were examined by the amount of porosities present in the SEM images. The results were tabulated and analyzed by Two way ANOVA and Tuckey`s B Post Hoc Test of Bonferroni and also by Independent t test after verifying the normality assumption by Q-Q Plot technique. The results show that group C1 bleached with 40% hydrogen peroxide was significantly differing and was least when comparing with other groups. It was concluded that there is significant differences observed in different concentrations of hydrogen peroxide and different remineralizing agents used and Group C1 bleached with 40% hydrogen peroxide showed the least mean value when comparing with other groups.drranjuraghu@gmail.comResearch712017Hydrogen peroxide,Microhardness,Tooth BleachingSatheesh Kumar S,Ranju Raghu,Kamaleshwaran VDepartment of Endodontics, Vinayaka Mission Sankarachariyar Dental College, Salem, Tamil Nadu, India.,Department of Endodontics, Vinayaka Mission Sankarachariyar Dental College, Salem, Tamil Nadu, India.,Department of Endodontics, Vinayaka Mission Sankarachariyar Dental College, Salem, Tamil Nadu, India.