去卵巢骨质疏松大鼠拔牙创模型研究

Study of tooth extraction wound model established in ovariectomized osteoporotic rats

目的通过卵巢切除术及大鼠左侧上颌第一磨牙拔除术建立去卵巢骨质疏松大鼠拔牙创模型。方法选用3个月龄雌性SD大鼠24只,随机分为模型组、对照组,每组12只,卵巢切除术2个月后对两组大鼠行左侧上颌第一磨牙拔除术,于卵巢切除术后2个月及拔牙术后第2、4、8周分4批处死大鼠,通过体质量、血清生化检测、Micro-CT检测及组织学观察对动物模型进行评价。结果卵巢切除术前模型组体质量((300.52±5.94)g)与对照组((298.88±6.21)g)相比无显著差异;术后2个月,模型组((355.64±12.09)g)相比于对照组((328.30±10.03)g)体质量明显增加(P<0.05)。卵巢切除术后2个月模型组雌二醇水平((10.21±4.35)pg/m L)较对照组((22.49±2.94)pg/m L)明显降低(P<0.05),同时模型组大鼠股骨远端骨小梁较为稀疏不连续。Micro-CT示拔牙术后(4周(0.113 8±0.009 9)mm,8周(0.122 7±0.019 7)mm)模型组骨小梁厚度均明显低于对照组(4周(0.142 3±0.010 6)mm,8周(0.201 3±0.052 7)mm)(P<0.05)。组织学观察显示拔牙术后模型组拔牙创骨小梁纤细,稀疏,不规则,骨量少,新骨愈合质量降低。结论采用卵巢切除术结合大鼠左侧上颌第一磨牙拔除术可建立去卵巢骨质疏松大鼠拔牙创模型,为探讨绝经后骨质疏松对拔牙创愈合的影响及其机制提供了有效的手段。

Objective To establish an experimental animal model of tooth extraction wounds in ovariectomized osteoporotic rats. Methods Twenty-four female SD rats aged 3 months old were randomly divided into two study groups as follows：the model group and the control group. 2 months after ovariectomy, both groups accepted left maxillary first molar extraction. The rats were sacrificed 2 months after ovariectomy and 2, 4, 8 weeks after tooth extraction respectively. Body weight, serum levels of biochemical indices, Mi- cro-computed tomography （Micro-CT） and histological examination were assessed. Results Before ovariectomy, there was no significant difference between the model group（（300.52±5.94） g） and the control group（（298.88±6.21） g） in body weight. Compared with the control group（ （328.30± 10.03）g）, the body weight increased significantly （P〈0.05） in the model group（ （355.64± 12.09）g） 2 months after ovariectomy. Estradiol was significantly lower （P〈0.05） in the model group（ （10.21±4.35） pg/mL） compared with the control group（（22.49±2.94） pg/mL） and the femurs trabecular was thinner in the model group 2 months after ovariectomy. The Micro- CT scanning demonstrated that the trabecular thickness in the model group（4-week（ 0.113 8±0.009 9）mm, 8-week （ 0. 122 7± 0.019 7）mm） was significantly lower than in the control group（4-week （0.142 3±0.010 6）mm, 8-week （0.201 3±0.052 7）mm） 4, 8 weeks after tooth extraction. Histology showed less and thinner trabeculae arranged in disorder, less bone mass and lower quality of new bone healing in the model group compared with the control group. Conclusions Experimental tooth extraction socket model in ovariectomized osteoporotic rats can be established by ovariectomy plus left maxillary first molar extraction. This model offers a good method to study the relationship between the healing of tooth extraction wounds and postmenopausal osteoporosis.