저출력 레이저가 백서의 교정적 치아이동에 미치는 영향

Abstract

Low energy laser irradiation can accelerate wound healing, differentiation of the fibroblast and chondroblast, collagen synthesis, and neural regeneration. If the bone remodelling could be promoted by the laser irradiation, orthodontic treatment period would be shortened due to the increased tooth movement rates. The purpose of this study was to investigate the effect of the low energy laser (904nm, Ga-As) irradiation on the first molar movement in rats. Eleven Sprague-Dawley rats were used in this study. NiTi closed coil spring was attached to the maxillary first molar and connected to the incisor for the application of the continuous orthodontic forces. The control group only received mechanical activation of the molar teeth. On the other hand, the experimental group received the same mechanical activation and was also irradiated with low energy laser (Ga-As, 60Hz) everyday for 4 minutes. On the 1, 5, 8, 12, and 26th day, the orthodontic appliance was removed and then dental model was made. The tooth movement distance was measured on the study model each day. The results were as follows: 1. The first molar receiving low energy laser(904nm, Ga-As) as well as orthodontic forces showed much more moving rates than the control group which only received orthodontic forces. 2. The difference of tooth movement distance between control and experimental group was significant util 8th day but not clear from 12th day to 26th day. 3. When the tissue samples from control group and experimental group were compared at 8th day, there was significant difference between the two groups. However at 26th day, no significant difference existed between them. Because the effect of the low energy laser was high at the early stage of orthodontic treatment, the use of Ga-As low energy laser could diminish the treatment period in especially minor tooth movement.