Abstract:

Objective:The aim of this studywas to investigate effects of lowenergy laseron the experimental toothmovement and the re- modeling of alveolar bone in rabbits.Methods:A total of 42 white rabbits were chosen and randomized into one control group and six experimental groups, with 6 rabbits in each group. After anesthesia with 2% pentobaritone sodium, orthodontic appliances consisting of a coil spring connected bilaterally the upper firstmolarwith the upper incisor by using a ligature wire. The force ex- erted at the time of insertion was approximately 80 g. The left side served as the control side, and the right side was the experi- mental side treated by receiving irradiation of lowenergy laser. The treatmentperiods of differentgroups lasted separately for1, 3, 5, 7, 14, 21 days respectively. The displacement extent of teeth was measured by employing the computer image analyzing sys- tem. The resultswere analyzed statistically. ThroughHE staining, the histomorphological characterof tissue around firstmolarwas also investigated, and numbers of osteoclasts were counted.Results:The displacement extent of teeth on the experimental side, which was irradiated by low energy laser, was more obvious than that of the normal control side. The difference was statistically significant 1, 3, 14, 21 days after the beginning of the treatment. Through histological observation under a lightmicroscope, the osteoclasts and osteoblasts on the experimental side remained more active than those of the control side. There is significant differ- ence in amount of osteoclasts between the experimental and the control sides, 3,5 or 7 days after the treatment (P<0.01, P<0.05).Conclusion:The irradiation of low energy laser promote tooth movement and remodeling of alveolar bone.

Key words: low energy laser, tooth movement, the remodeling of alveolar bone