同时应用雌激素和二膦酸盐对骨质疏松大鼠种植体骨结合的累加效应

目的:研究在切除卵巢的大鼠体内,局部应用二膦酸盐(BPs)和全身应用雌激素,对有羟基磷灰石(HA)涂层的种植体骨结合的影响.方法:20只雌性大鼠接受双侧卵巢切除术12周后,在每只大鼠的双侧胫骨近端各植入1颗含有HA涂层的种植体,植入左侧胫骨的种植体携带BPs,植入右侧胫骨的种植体不含BPs.大鼠平均分成2组,其中一组接受17β-雌二醇(E)皮下注射,另一组注射安慰剂.4组大鼠分别为:对照组、雌激素组(E组)、二膦酸盐组(BPs组)、雌激素+二膦酸盐组(E+ BPs组).种植手术12周后,手术取出带有种植体的胫骨,用显微CT和推出试验来评估骨结合效果.结果:E+BPs组与空白对照组相比,种植体周围的相对骨体积增加了2.3倍,骨结合率增加了1.9倍,最大推出力增加了3.3倍.E组和BPs组种植体的固位力也增加了,但效果弱于E+BPs组.结论:全身应用雌激素和局部应用BPs对涂有HA涂层的种植体的骨结合具有累加效果.

The effects of estrogen replacement therapy and local application of bisphosphonates on the implant osseointegration in ovariectomized rats

Objective:To investigate the effect of local application of bisphosphonates(BPs) and systemic estrogen replacement therapy on the osseointergration of hydroxyapatite-coated implant in ovariectomized rats.Methods:12 weeks after ovariectomiy,each of the 20 female rats accepted 2 hydroxyapatite-coated implant screws in proximal tibiae,with and without immobilized BPs respectively on 2 sides.Half of the animals received subcutaneous injections of 17β-estradiol(E).Thus,there were 4 groups:control,estrogen (E),BPs and E + BPs.Tibiae with the implant screws were examined by μ-CT and push-out test was performed 12 weeks after implantation.Results:The bone volume ratio around screws and the percentage osteointegration in E + BPs group increased by 2.3-fold and 1.9-fold,and the push-out force by 3.3-fold respectively,compared to untreated controls.In group E the fixation of screws was also increased but less than that in group E + BPs.Conclusion:Systemic estrogen replacement therapy and locally immobilized BPs have additive effects on osseointergration of hydroxyapatite-coated implant screws in ovariectomized rats.