弱激光照射对兔牙移动速度及骨改建影响的实验研究

目的:探讨弱激光照射对兔实验性牙齿移动速度及骨改建作用的影响。方法:将42只大耳白兔随机分为7 组,即正常组、实验1、3、5、7、14、21 d组。2%戊巴比妥钠麻醉下于双侧上颌第一磨牙与切牙间拴结不锈钢螺簧,施力80 g。左侧为对照侧,右侧为照射侧,进行弱激光照射。通过计算机测量分析牙齿移动的距离,HE染色进行组织学观察和破骨细胞计数。结果:经弱激光照射侧牙齿移动距离普遍大于对照侧,1、3、14、21 d有显著差异。光镜下的组织学观察显示,经弱激光照射侧血管化反应、破骨与成骨活动均较对照侧活跃。破骨细胞计数3、5、7 d组与对照侧相比有显著差异(P<0101,P<0.05)。结论:弱激光照射促进了兔实验性牙齿移动速度与骨改建。

Effects of Low Energy Laser on Tooth Movement and Remodeling of Alveolar Bone in Rabbits

Objective:The aim of this study was to investigate effects of low energy laser on the experimental tooth movement and the remodeling 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 first molar with the upper incisor by using a ligature wire. The force exerted at the time of insertion was approximately 80 g. The left side served as the control side, and the right side was the experimental side treated by receiving irradiation of low energy laser. The treatment periods of different groups lasted separately for 1, 3, 5, 7, 14, 21 days respectively. The displacement extent of teeth was measured by employing the computer image analyzing system. The results were analyzed statistically. Through HE staining, the histomorphological character of tissue around first molar was 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 light microscope, the osteoclasts and osteoblasts on the experimental side remained more active than those of the control side. There is significant difference 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.;