不同正畸力对大鼠牙周组织张力侧BMP-2蛋白表达的影响
Effects of different orthodontic force on expression of BMP-2 in periodontal tissue of tension side

目的:观察正畸牙齿移动过程中不同正畸力对大鼠牙周组织张力侧骨形成蛋白2(BMP-2)蛋白表达的影响。方法:选择健康雄性Wistar大鼠60只,分成4组(n=15),分别施加0 g(A组)、30 g(B组)、50 g(C组)、80 g(D组)力,建立大鼠牙齿移动模型。每组分别于加力后第1、3、7、14、21 天测量牙齿移动距离并处死3只大鼠,取上颌第一磨牙,HE染色法观察牙周组织的形态学变化,免疫组化法检测牙周组织张力侧BMP-2蛋白的表达。结果:各组大鼠牙齿移动距离明显不同(F组间=465.606,F时间=87.405,F交互=13.541,P均<0.001)。HE染色显示A组牙周组织没有明显变化; B组与C组牙周组织改建活跃,在牙周组织张力侧可见新生的成骨细胞; D组可见牙周膜纤维排列混乱,牙根局限性吸收。BMP-2蛋白主要分布于牙周韧带中,尤其是近牙槽骨和牙骨质的区域染色较强,各加力组与A组相比BMP-2蛋白表达增加(P均<0.05)。结论:牙周组织张力侧BMP-2蛋白的表达与力值大小有关,50 g正畸力是促进大鼠牙周组织改建的最适力值。
Aim: To explore the effects of different orthodontic force on the expression of bone morphogenetic protein-2(BMP-2)in the tension side of periodontal tissue of rats during the orthodontic movement of teeth.Methods: A total of 60 healthy Wistar rats were allocated into 4 groups(n=15):group A(0 g),group B(30 g),group C(50 g),and group D(80 g).The model of orthodontic tooth movement was established after giving a force.The distance of orthodontic tooth movement was determined after adding the forces for different time. Then the rats were executed to observe the periodontal tissue of maxillary first molars by HE staining. And the expression of BMP-2 in periodontal tissue in the tension side was detected by SP method.Results: The distances of orthodontic tooth movement showed a significant difference among A,B,C,D groups(Fgroup=465.606,Ftime=87.405,Finteraction=13.541,P<0.001). HE results showed that there were no significant changes in the periodontal tissue in group A. The periodontal tissue rebuilt actively in group B and C,while the osteoblast was regenerated in the tension side of the periodontal tissue. The fiber of the periodontal ligament was in disorder and the dental root was absorbed in group D. BMP-2 was mainly distributed in the periodontal ligament, especially in the alveolar bone and cementum region.With the increasing of the orthodontic force, the expression of BMP-2 in the other groups increased compared with group A(P<0.05).Conclusion: The expression of BMP-2 is related with the intensity of orthodontic force. A force of 50 g is the best force for the remodeling of the periodontal tissue in rats