不同正畸力值对长期饮用碳酸饮料大鼠正畸牙移动牙根吸收影响

目的:研究不同的正畸力值对长期饮用碳酸饮料大鼠牙根吸收的影响.方法 :选择1月龄雌性SD大鼠20只,每只每天喂养可乐50 mL,3个月后将20只大鼠按施加力值分为4组,分别为0 g(A组)、30 g(B组)、50 g(C组)和80 g(D组),加正畸装置于上颌第一磨牙.并于喂可乐0 d、3个月、加力21 d 3个时间点测大鼠骨密度(BMD),术后21 d处死取大鼠上颌第一磨牙及附近牙槽骨组织块,进行锥形束CT检测和HE染色观察牙根吸收情况,组织切片计算牙根吸收指数,TRAP染色观察破骨细胞数量.结果 :随着喂养可乐时间增加,各组BMD随之降低,差异有统计学意义(P<0.05),但同一时间点各组BMD差异无统计学意义(P>0.05);锥形束结果显示牙根吸收指数和破骨细胞计数均为D组>C组>B组(P<0.05~P<0.01),B组与A组差异无统计学意义(P>0.05).B组正畸牙移动过程中骨改建较C、D组活跃.结论 :在30 g的力值作用下对长期饮用碳酸饮料大鼠正畸牙移动牙根吸收的影响最小,而随着力值的增加大鼠牙根吸收程度也随之加重.

Effect of different orthodontic force values on tooth root resorption in rats with long-term drinking carbonated beverage

Objective:To study the effects of different orthodontic force values on the root resorption in rats with long-term drinking carbonated beverage. Methods:Twenty SD female rats(1 month old) were fed with 50 mL Coca-Cola each day. After 3 months,the rats were divided into the group A(0 g),group B(30 g),group C(50 g) and group D(80 g) according to the applying force value,and added orthodontic device in maxillary first molar. The BMD in rats at 0 d,21 d and 3 months of feeding Cola was measured. The maxillary first molar and near tissue were obtained after 21 days of operation,and detected using CBCT and stained using HE to observe the root absorption. The root resorption index was calculated by tissue section,and the number of osteoclasts was observed by TRAP staining. Results:With the increasing of feeding Cola time,the BMD in each group gradually decreased,the difference of which was statistically significant(P<0. 05). At the same time-point,the difference of BMD between each group was not statistically significant(P>0. 05). CBCT results showed that the root resorption in group D,group C and group B gradually decreased. The tooth root resorption index and number of osteoclasts in group D,group C and group B gradually decreased(P<0. 01),the difference of those between group B and group A was not statistically significant(P>0. 05). The bone remodeling in group B during orthodontic tooth movement is more active than that in group C and group D. Conclusions:The effect of 30 g force value on the root resorption in rats with long-term drinking carbonated beverage is the minimum,and the root resorption gradually increases with the increasing of force value.