静止期牙周病动物模型的建立及其骨微结构的Micro-CT观察

Establishment of animal model of quiescent periodontitis and Micro-CT ervation of bone microstructure

目的模拟临床牙周病患者正畸治疗的牙周病理环境,建立静止期牙周病动物模型,并使用Micro-CT观察其牙槽骨骨微结构的变化。方法将115只8周龄C57BL/6雄性小鼠随机分为对照组(n=30)和实验组(n=85),用丝线结扎实验组小鼠右侧上颌第一磨牙建立静止期牙周病动物模型,结扎6周后去除结扎丝,将实验组小鼠随机分为牙周病组(n=35)和牙周治疗组(n=44),牙周病组小鼠不作处理,牙周治疗组小鼠进行常规牙周刮治,按照术后不同观察时期(牙周治疗后4周、6周、8周)分组、取材,进行Micro-CT观察,比较各组小鼠右侧上颌第一磨牙牙槽骨矢状面余留骨量百分比、骨密度、骨体积分数、骨小梁数量、骨小梁分离距离、骨小梁厚度的差别。结果成功建立静止期牙周病动物模型,样本符合观察要求。Micro-CT显示,牙周治疗后4周,牙周病组和牙周治疗组小鼠右侧上颌第一磨牙矢状面余留骨量百分比均小于对照组,差异有统计学意义(53.79%±10.07%,60.96%±12.14%vs 89.13%±5.88%,P<0.05);牙周治疗组骨密度、骨体积分数、骨小梁数量、骨小梁厚度均小于对照组,牙周治疗组骨小梁分离距离大于对照组,差异有统计学意义(P<0.05)。牙周治疗后4周,牙周治疗组骨密度、骨小梁厚度大于牙周病组,骨小梁分离距离小于牙周病组,差异有统计学意义(P<0.05)。牙周治疗后8周,牙周病治疗组小鼠骨小梁分离距离小于牙周治疗后4周,骨小梁厚度大于牙周治疗后4周,差异有统计学意义(P<0.05)。结论本实验建立的静止期牙周病动物模型设计合理,科学易行,可以模拟临床牙周病患者正畸治疗的牙周病理环境,为研究牙周病患者正畸治疗的方式和效果提供有利条件。

Objective To establish an animal model of stationary periodontitis for simulating the periodontal pathological environment of orthodontic patients in orthodontic treatment,and to observe the changes of microstructure of alveolar bone by Micro-CT. Methods The mice were randomly divided into control group（ n = 30） and model group（ n = 85）. The first maxillary right molar was ligated in experimental group,and dislodged 6 weeks later. The model mice were randomly divided into periodontal disease group（ n = 35） and periodontal treatment group（ n = 44）. The mice were not treated in periodontal disease group,but treated with conventional periodontal scaling in periodontal treatment group,and the microstructure of alveolar bone was observed by Micro-CT after periodontal treatment for4 weeks,6 weeks,8 weeks. And the residual bone mass,bone density,bone volume fraction,number of trabecular bone,separation of trabecular bone and thickness of trabecular bone at first molar on the right upper jaw were compared. Results An animal model of quiescent periodontitis was established successfully,and the model met the requirements of the observation. At 4 week after periodontal treatment,the residual bone mass of the first molar on the right upper jaw was lower in periodontal disease group and periodontal treatment group than in control group（ 53. 79% ± 10. 07%,60. 96% ± 12. 14% vs 89. 13% ± 5. 88%,P 0. 05）,and bone density,bone volume fraction,number of trabecular bone and thickness of trabecular bone were lower in periodontal treatment group than in control group,and the distance of trabecular bone separation was larger in periodontal treatment group than in control group（ P 〈0. 05）. At 4 week after periodontal treatment,the bone density and the thickness of trabecular bone were higher in periodontal treatment group than in periodontal disease group,and the distance of trabecular bone separation was lower in periodontal treatment group than in periodontal disease group. At 8 week after periodontal treatment,the distance of trabecular bone separation in periodontal disease group was lower than that at 4 week after periodontal treatment,and the thickness of trabecular bone in periodontal treatment group was higher than that at 4 week. Conclusion The animal model of stationary periodontitis established in this experiment is reasonable and scientific,which can be fully used to simulate the case of orthodontic treatment of patients with periodontal disease and provide favorable conditions for the further study of orthodontic treatment of periodontal disease.