Background and objectives: Fluoride is being used for the prevention of dental caries since a long time. Incorporation of fluoride in pit and fissure sealants has been found to reduce initiation and progression of pit and fissure caries. Authors conducted this study to evaluate and compare the effect of fluoride releasing pit and fissure sealants on the inhibition of demineralization of adjacent enamel and to reduce wall lesion frequency. Materials and methods: A total of 60 caries-free human third molars were randomly assigned into three groups receiving conventional resin sealant without fluoride (Group A), fluoride releasing resin sealant (Group B), glass ionomer pit and fissure sealant (Group C). Fissure cavities of 5 × 2 × 1.5 mm were prepared on buccal surfaces of teeth using fissurotomy bur and sealants were applied onto the cavities. The teeth were then thermocycled and exposed to acidified gelatin gel for 6 weeks to induce caries like lesions. A 150 μm section was taken from each tooth and observed under polarized light microscope to measure the depth of advancing front of outer enamel lesion. The outer lesion depths of all three groups were compared. Results: Enamel demineralization was least in glass ionomer pit and fissure sealant while the demineralization exhibited by nonfluoridated resin and fluoridated resin were comparable. Wall lesion frequency was found to be 0% in all groups. Conclusion and interpretation: The glass ionomer pit and fissure sealant exhibited highest anticariogenic efficacy and hence can be advocated as a means of preventing dental caries.