低强度激光对兔正畸牙牙周膜血管化的影响

Effects of low energy laser on vascular changes in periodontal ligament of rabbit orghodontic tooth movenent

目的 :探讨低强度激光 (lowenergylaser)照射对兔正畸牙牙周膜 (periodontalligament,PDL)血管化的影响。方法 :3 0只大耳白兔分为1d、3d、5d、7d、14d和 2 1d组 ,每组 5只。 80g力拉兔双侧上颌第一磨牙近中移动。左侧为对照组 ,右侧为实验组进行低强度激光照射。采用墨汁血管灌注及计算机图像分析的方法研究兔正畸牙PDL血管密度和面积的变化。结果 :实验组和对照组正畸牙的压力侧血管密度高峰值分别为 3 0个 mm2 和 2 7个 mm2 ,血管面积值分别为 7872 9.40um3和 710 2 1.0 0um2 ,高峰值出现在施力后第 7天。张力侧的实验组与对照组血管密度高峰值分别为 3 2个 mm2 和 2 8个 mm2 ,血管面积值分别为 913 2 9.44 μm2 和 85 0 46.0 0 μm2 ,高峰值出现在第 14天。实验组的压力侧与张力侧血管密度和面积均大于对照组 (P <0 .0 1)。结论 :低强度激光照射能促进兔正畸牙PDL的血管化反应 ,从而有益于正畸牙周组织的改建。

Objective To analyze the effects of low energy laserirradiation on vascular change in periodontal ligament(PDL) of rabbit or thodontic tooth movement.Methods The first molar of rabbits was chosen as orthodontic tooth,using 80g force to make the teeth mesial movement.LPL irradiated the right side of the orthodontic tooth,and the left side used as control.Radiation time of LPL ranged from 1 day to 5 day,once a day,15 min every time.30 rabbits were sacrificed at 1d,3d,5d,7d,14d and 21d.Vascular perfusion of ink and computerized image analysis were used to investigate the change of vascular density and area in PDL.Result The peak values of vascular density were 30/mm 2 and 27/mm 2 on the experimental group and control group,and the values area were 78729.40μm 2 and 71021.20μm 2,respectively.The peak value of vascular density and area in pressure side occurred at the 7th day after employing orthodontic force.The peak value in tension side occurred at the 14th day,and the values of vascular density were 32/mm 2 and 28/mm 2 in experimental group and control group,the values of area were 91339.44 μm 2 and 85046.00 μm 2,respectively.Vascular density and area significantly increased in irradiation group compared with control group (P<0.01).Conclusion Low energy laser radiation can accelerate the vascularized reaction in PDL of the removed teeth,which may promote the reconstruction of PDL and alveolar bone.