BACKGROUND Dentin hypersensitivity (DH) is a sudden short sharp pain best explained by hydrodynamic theory. Several agents are available throughout the market that can treat DH either by blocking the nerves that helps in conducting pain or by blocking the open dentinal tubules. The aim of the present study was to compare the tubule occluding efficacy of four different desensitizing dentifrices under scanning electron microscope (SEM). METHODS Sixty-two dentin blocks measuring 5 mm × 5 mm × 3 mm were obtained from extracted human molar teeth and were randomly divided into five groups: Group 1 - no treatment (control, n = 2); Group 2 - Pepsodent Pro-sensitive relief and repair (n = 15); Group 3 - Sensodyne repair and protect (n = 15); Group 4 - Remin Pro (n = 15); Group 5 - Test toothpaste containing 15% nano-hydroxyapatite (n-HA) crystals (n = 15). The specimens were brushed for 2 min/day for 14 days and stored in artificial saliva. After final brushing, specimens were gold sputtered and viewed under SEM at ×2000 magnification. Results obtained were statistically analyzed using nonparametric Kruskal-Wallis test and least significant difference post hoc test. RESULTS All test groups showed significant increase in dentin tubule occlusion as compared to control group. The highest percentage of tubules occluded was shown by Group 4 and Group 5 which was significantly different from other groups (P ≤ 0.05), and there was no significant difference in tubule occlusion among them. CONCLUSIONS Newer desensitizing dentifrices containing 15% n-HA and Remin Pro can provide effective tubule occlusion and thereby reduce the pain and discomfort caused by DH.