Objective: To evaluate and compare the effect of zinc carbonate - nano hydroxyapatite (n-HA) (Biorepair toothpaste) and casein phosphopeptide - amorphous calcium phosphate (CPP-ACP) (GC Tooth Mousse creme) on the depth of white spot lesions (WSLs). Materials and Methods: Thirty six human premolar teeth with artificially induced WSLs were randomly assigned to three groups (n=12). Group I: n-HA toothpaste, Group II: CPP-ACP topical creme, and Group III: negative control. The teeth were longitudinally sectioned and photographed using polarized light microscopy (PLM) and the depth of enamel subsurface demineralization was measured. Statistical analysis was performed. Results: The n-HA group showed the least mean lesion depth, followed by the CPP-ACP group (76.8 ± 10.2 μm and 79.8 ± 9.7 μm respectively), while, the control group showed the largest mean lesion depth (107.8 ± 8.5 μm). The difference between the control group and each of the test groups was significant (p < 0.001), while there was no significant difference between the two test groups. Conclusion: Both n-HA and CPP-ACP showed significant remineralization of the early enamel lesions compared to the control group.