【摘要】 [目的]研究大鼠前牙保持阶段,张力侧牙周膜中IGF-I的表达,探讨IGF-I在大鼠前牙正畸后保持阶段对牙周组织改建中的作用,分析大鼠前牙加力后最短保持时间,推测临床正畸治疗后最短保持时间。[方法]选择雄性大鼠36只,随机分为6组,空白对照组及实验组5组,按保持时间长短,分别为保持1、3、7、14及21 d组,每组6只。实验组在建立大鼠保持期模型后,按分组要求处死大鼠,空白对照组则同条件饲养7 d后直接处死。用免疫组化法分析大鼠前牙牙周膜张力侧IGF-I的表达。[结果]保持1、3、7、14 d组IGF-I表达呈时间依赖性且表现为下降趋势,保持21 d组与空白对照组相比,差异无统计学意义(P <0. 05)。[结论]IGF-I参与保持期大鼠前牙牙周膜张力侧的骨改建,并与保持时间呈重度相关,推测保持约21 d后牙周组织张力侧骨改建基本完成。更多还原

【Abstract】 [Objective]This study was carried out aiming to investigate the expression of IGF-1 in the pericementum on the tension side of the anterior teeth during retention stage in rats in addition to exploring the significance of IGF-1 on periodontal reconstruction in the period of retention after orthodontic treatment of anterior teeth in rats so as to analyze the shortest retention time of anterior teeth after applying force and also to predict the shortest retention time after orthodontic treatment in clinical practice.[Methods]A total of 36 male SD rats were selected and randomly divided into 6 groups of one control group and 5 experimental groups with a total number of 6 rats in each one. The latter 5 experimental groups were subgrouped according to the length of retention,including 1 day retention group,3 day retention group,7 day retention group,14 day retention group and 21 day retention group. After the establishment of rats model during the retention stage,rats were sacrificed in the experimental groups according to each group requirement. Furthermore,rats in the control group were put to death directly following 7 days of feeding under the same condition.Immunohistochemistry was the selected modality to measure the expression of IGF-1 in the pericementum on the tension side of anterior teeth in rats.[Results]IGF-1 expression showed a time-dependent decrease in the 1 day retention group,3 d retention group and 7 d retention group. However,there was no significant statistical difference in the comparison of the 14 day retention group and the 21 d retention group with the control group( P < 0. 05). [Conclusion]IGF-1 is involved in bone remodeling of the pericementum on the pressure side of anterior teeth during retention stage in rats with a high correlation to the retention time. Bone remodeling of the periodontium on the tension side is speculated to be completed basically after retention for about 14 d.更多还原