To evaluate the effect of functional dairy products (flavoured milk) containing stevia and xylitol sugar substitutes on enamel surface remineralization in experimental rats' teeth. Rats were infected with Mutans streptococci and were divided to Group 1: Rats that received functional dairy food containing sucrose. Group2: Rats received functional dairy food containing xylitol. Group 3: Rats received functional dairy food containing stevia. Anterior incisor teeth were extracted. Enamel surface of each specimen was studied using scanning electron microscope (SEM Quantum 52 SEG), Photographs were obtained at x1000, x2000 magnification for all the specimens. Enamel surface minerals were measured using EDX: wt% of minerals (Ca, P, Mg, F). The results of this study showed that there was a significant increase in demineralization of the enamel surface in rats fed diet containing sucrose (Group I).In group II and III, where rats were fed diet containing xylitol and Stevia, the results showed that there was increase in remineralization of enamel surface and high statistically significant results when compared to group I for elements Ca and P. Group I, group II and group III showed low statistically significant results compared to control group for element Mg. When F was considered there was no statistically significant difference between groups, except group II which showed the highest results. This study concluded that sucrose possesses a strong cariogenicity and demineralization of enamel. Dairy product containing stevia was more effective than that containing xylitol in remineralization of enamel surface and increase of remineralizing minerals content in experimental rats.