OBJECTIVE: The purpose of this study was to evaluate the cutting efficiency and morphological changes of root dentin irradiated by an Er:YAG laser in vitro. STUDY DESIGN: Thirty-two root dentin blocks were divided into 4 groups. The irradiation conditions were as follows: Group 1 (G1): 30 mJ, 10 pps, 1 mm/s, 20 times; Group 2 (G2): 30 mJ, 10 pps, 1 mm/s, 10 times; Group 3 (G3): 30 mJ, 10 pps, 2 mm/s, 20 times; and Group 4 (G4): 30 mJ, 25 pps, 1 mm/s, 10 times. After being irradiated, the blocks were observed by mu-CT and their width and depth were measured. Moreover, SEM observations were performed. RESULTS: There were significant differences between G1 and G2, between G1 and G3, between G2 and G4, and between G3 and G4 for both width and depth (P < .05). The SEM observations showed that no smear layer was present on the surface of any of the samples. CONCLUSION: These results show that the Er:YAG laser operated under the conditions used in this study is an effective tool for root canal preparation.
OBJECTIVE: The purpose of this study was to evaluate the cutting efficiency and morphological changes of root dentin irradiated by an Er:YAG laser in vitro. STUDY DESIGN: Thirty-two root dentin blocks were divided into 4 groups. The irradiation conditions were as follows: Group 1 (G1): 30 mJ, 10 pps, 1 mm/s, 20 times; Group 2 (G2): 30 mJ, 10 pps, 1 mm/s, 10 times; Group 3 (G3): 30 mJ, 10 pps, 2 mm/s, 20 times; and Group 4 (G4): 30 mJ, 25 pps, 1 mm/s, 10 times. After being irradiated, the blocks were observed by mu-CT and their width and depth were measured. Moreover, SEM observations were performed. RESULTS: There were significant differences between G1 and G2, between G1 and G3, between G2 and G4, and between G3 and G4 for both width and depth (P < .05). The SEM observations showed that no smear layer was present on the surface of any of the samples. CONCLUSION: These results show that the Er:YAG laser operated under the conditions used in this study is an effective tool for root canal preparation.