This study was to determine the efficacy in the remineralization on premary teeth following the application of toothpaste with and without sodium fluoride. All tooth were checked using microhardness tester and the calcium (Ca) and phosphorous (P) concentration by electron probe microanalyzer (EPMA) analysis for the 4 weeks. The collected data was analysed using the statistical software program SPSS, 20.0. The applied enamel of premary teeth with 0.243% fluoridated toothpaste resulted in significant differences in the microhardness values (p>0.05). The Ca and P concentrations of applied premary teeth with fluoridated toothpaste were also significant difference in norm wt% (p>0.05). As a results, a increasing the surface microhardness of the premary teeth and providing a remineralizing effect by increased Ca and P concentrations.