Low-energy laser irradiation accelerates the velocity of tooth movement via stimulation of the alveolar bone remodeling.

INTRODUCTION: Previously, the authors have reported the acceleration of tooth movement and osteoclastogenesis on the pressure site in an experimental tooth movement model by low-energy laser irradiation (LELI), which stimulated the RANK/RANKL system and c-fms/macrophage colony-stimulating factor system. However, the effect of LELI on osteogenesis on the tension site is not known clearly. Moreover, the temporal changes in alveolar bone during tooth movement have not been investigated as yet. Therefore, the present study was designed to examine the effects of LELI on alveolar bone remodeling during experimental tooth movement, and observe the temporal bone mineral density (BMD) using micro-computed tomography (muCT). MATERIALS AND METHODS: To induce experimental tooth movement in rats, 10 g force was applied to the upper right first molar with Nickel titanium closed-coil. Next, a gallium-aluminum-arsenide (Ga-Al-As) diode laser was used to irradiate the area around the moved tooth, and BMD and the amount of tooth movement were measured by muCT scanning for 21 days. Histopathological examination was also performed. RESULTS: The amount of tooth movement in the LELI group was significantly greater than in the non-irradiation group by the end of the experimental period. Further, compared with the non-irradiation group, the fall of BMD was less in the LELI group. CONCLUSION: These findings suggest that LELI accelerates the velocity of tooth movement via stimulation of the alveolar bone remodeling.