牙周再生术后2周和12周牙周组织对正畸力应答的实验研究

Experimental Study on Orthodontic Force Response in Periodontal Tissue after Periodontal Regeneration

目的:研究不同正畸开展时机对牙齿移动速度及牙周组织再生的影响,以评价牙周组织对正畸力的应答反应。方法:建立巴马小型猪牙周骨缺损模型,应用富血小板纤维蛋白联合牙周植骨术治疗骨缺损,分别在再生后2周和12周开展正畸牵引,正畸6周后处死动物,行牙周指标、Micro CT、组织形态学及免疫组织化学检测。结果:与再生后12周正畸组相比,牙周再生后2周正畸组牙齿移动速度更快(P=0.025);骨量正相关指标包括相对骨体积、骨小梁数量、骨小梁厚度均较高(P=0.019、0.014、0.024);而骨量负相关指标:骨小梁分离度、骨表面积和骨体积的比值、骨小梁模式因子均较低(P=0.033、0.029、0.008);正畸骨改建更为活跃,新生骨量更多;骨保护蛋白和骨形成蛋白2表达水平均更高(P=0.006、0.015)。结论:牙周再生术后2周较12周正畸牙齿移动速度更快,新骨生成更多,骨保护蛋白和成骨蛋白表达更高。

Objective:To study the effects of orthodontic timing(2 and 12 weeks)on tooth movement speed and periodontal tissue regeneration,and to evaluate the response of periodontal tissue to orthodontic force.Methods:A periodontal bone defect model in Bama miniature pigs was established.Platelet-rich fibrin(PRF)combined with periodontal bone grafting was used to treat bone defect.Orthodontic traction was carried out at 2 and 12 weeks after regeneration.Animals were sacrificed after 6 weeks of orthodontics.Periodontal parameters,micro-CT,histomorphology,and immunohistochemistry were examined.Results:Compared with 12 weeks after regeneration,the orthodontic group at 2 weeks after regeneration had a faster tooth movement speed(P=0.025).Positive correlations of bone mass included higher relative bone volume,number of bone trabecular and thickness of bone trabecular(P=0.019,P=0.014,P=0.024).Negative correlations of bone mass:trabecular segregation,ratio of bone surface area to bone volume,and trabecular mode factor were lower.(P=0.033,P=0.029,P=0.008).Orthodontic bone remodeling was more active,new bone mass was more,and the expression levels of osteoprotegerin and bone morphogenetic protein 2 were higher(P=0.006,P=0.015).Conclusion:Two weeks after periodontal regeneration,the orthodontic teeth move faster,new bone formation is more,and the expressions of osteoprotegerin and osteogenic protein are higher.