Purpose: The purpose of this study was to investigate the cutting efficiency of coarse grit diamond burs with air-turbine handpiece on natural tooth. Materials and methods: Four groups of coarse grit diamond bur were selected: Komet (A), Shofu (B), Premier (C), and Mani (D). The extracted maxillary central incisors were used, and ten cuts were made on each specimen, using the rotary diamond burs. The surface of each bur was measured at the upper, middle, and bottom of the bur with confocal laser scanning microscope and imaged with SEM. The data were analyzed with one-way ANOVA and t-test at the significance level of 0.05. Results: The surface roughness was measured. At the A diamond bur, the Sa values were 52.93μm52.93μm, 48.32μm48.32μm, 46.79μm46.79μm, 45.06μm45.06μm, and 43.43μm43.43μm for control, test 1, 2, 3, and 4 respectively. The Sa values were 50.68μm50.68μm, 45.62μm45.62μm, 44.41μm44.41μm, 44.10μm44.10μm, and 42.46μm42.46μm for B diamond bur, 58.02μm58.02μm, 55.53μm55.53μm, 52.22μm52.22μm, 48.26μm48.26μm, and 45.36μm45.36μm for C diamond bur, and 50.11μm50.11μm, 46.73μm46.73μm, 45.46μm45.46μm, 42.58μm42.58μm, and 41.80μm41.80μm for D diamond bur. Surface roughness after each bur use showed significant changes, but no significant difference was found in surface roughness change between bur systems. Conclusions: Surface roughness in the same bur system showed significant differences after each tooth preparation. However no statistically significant differences were found in surface roughness between bur systems. The SEM images between control and test 4 showed the abraded particles.