Background: To assess the efficacy of sodium fluoride and silver diamine fluoride in arresting caries. Materials & methods: 20 demineralised dentine blocks were enrolled and were broadly divided into two categories with 10 specimens in each group; Group A- Treated with SDF while Group B- Treated with NaF. All the blocks were subjected to a Streptococcus mutans biofilm challenge. Lesion depth, precipitates' characteristics and matrix (collagen)-to-mineral ratio were evaluated by micro-computer tomography (micro-CT). All the results were recorded in Microsoft excel sheet and were analysed using SPSS software. Results: Mean depth of the lesions was 169.5 μm among the group A specimens while it was 208.4 μm among group B specimens. While analysing statistically, significant results were obtained. Conclusion: Silver diamine fluorideis a more effective caries management reagent than Sodium fluoride. Key words: Sodium fluoride, Silver diamine, Caries