Carbonate apatite has a similar structure to the inorganic component of teeth and bone. Although carbonate apatite is widely used as a bone substitute, there are no reports on its use as a desensitizing dentifrice. This in vitro study evaluated the relative abrasivity of the dentifrice containing nano-sized carbonated apatite (n-CAPs) using a Surface Profile Method (SPM). The dentin specimens were made from the root of extracted human molars. The cervical part of the teeth was sectioned with a diamond wheel disk. The teeth were embedded into an epoxy resin mold and the surface was gradually polished using silicone carbide paper. After grinding, the degree of surface roughness was examined within the range of 2 mm with tapping. The British Standard Institution reference dentifrice (BSI: CaCO3 40%) and the experimental dentifrices (group 1: n-CAPs 30%, group 2: n-CAPs 15% and silica 15%, group 3: n-CAPs 5% and silica 25%, group 4: silica 30%, group 5: CaCO3 10% and SrCl2 10%) were compared. The dentifrice slurries were prepared by mixing 24 grams of the dentifrice in 12 ml distilled water. Each tooth specimen was brushed 1,000 times with the dentifrice slurries using a back-and-forth stroke. The relative abrasivity of each dentifrice was evaluated by determining the ratio of the BSI standard dentifrice to each experiment. The results were analyzed using one-way ANOVA and Tukey’s multiple comparisons using Window SPSS (Statistical analysis system) 12.0. According to the results, Group 1 (3.2), which contained only n-CAPs appeared to have the lowest abrasivity than the BSI dentifrice (100). However, Groups 2 (124.2), 3 (137.9) and 4 (178.1), which contained n-CAPs and silica, appeared to have a higher abrasivity than the BSI dentifrice (p>0.05). The relative abrasivity of group 5 (38), which was a commercial desensitizing dentifrice, was relatively lower. It appears that the higher abrasivity of the experimental is due to the shape and size of the silica component. Therefore, n-CAPs itself has no influence on the abrasivity of the dentifrice. The main reason for the low abrasivity of n-CAPs is believed to be its small particle size (range 50-90nm).