含镁羟基磷灰石涂层对卵巢摘除大鼠种植体骨整合的影响

目的探讨羟基磷灰石涂层(hydroxyapatite,HA)中加入镁元素对植入卵巢摘除(ovariectomized,OVX)大鼠体内种植体的稳固性的影响。方法采用溶胶-凝胶法制备种植体表面涂层,对照组为传统的羟基磷灰石涂层,实验组为用镁元素替代羟基磷灰石中10%钙元素的涂层(magnesium-containing hydroxyapatite,MgHA)。另取18只OVX大鼠,随机分为2组,一组在双侧股骨远心端各植入1枚HA涂层种植体,另一组则植入MgHA涂层种植体。12周后,连同周围骨组织取出种植体进行组织形态计量分析、Micro-CT评价、生物力学测试。结果 MgHA组骨-种植体接触率、骨面积比率分别为(52.57±4.73)%、(36.76±3.31)%,HA组为(34.06±5.20)%、(27.26±2.92)%;MgHA组的最大推出强度、界面剪切强度为(63.98±4.08)N,(2.63±0.25)N/mm2,HA组为(41.44±7.07)N,(2.22±0.33)N/mm2,P<0.01。此外,MgHA组骨体积分数(24.5±6.1)%、骨小梁厚度(80.6±11.9)μm、骨小梁数量(5.8±0.5)mm-1、骨小梁分离度(194.7±38.2)μm、连接密度(51.9±5.6)mm-3、骨整合率(58.6±6.2)%;而HA组为(16.6±4.3)%、(68.4±10.3)μm、(5.2±0.6)mm-1、(220.8±30.6)μm、(44.1±4.5)mm-3、(45.1±3.8)%,除骨小梁分离度无统计学差异外,其余P<0.05。结论镁元素能改善骨质疏松骨中种植体的生物性能。

Effect of magnesium-containing hydroxyapatite coating on implant osseointegration in ovariectomized rats

Objective To investigate the effects of magnesium-containing hydroxyapatite(MgHA) coating on implant fixation in ovariectomized(OVX) rats.Methods Control group possessed hydroxyapatite(HA) coating prepared by sol-gel method,while the experimental group used coating of MgHA with 10% Ca2+ replaced by Mg2+ prepared in the same way.18 OVX rats were randomly divided into two groups;one group received a HA implant separately in the bilateral femoral telecentric end and the other group got MgHA implants.12 weeks later,implants together with surrounding bone tissue were harvested for histomorphometry,Micro-CT evaluation,and biomechanical testing.Results In MgHA group,bone-to-implant contact rate and bone area ratio were(52.57±4.73)%,(36.76±3.31)%,while those in HA group were(34.06±5.20)%,(27.26±2.92)%.The maximum push-out force and interfacial shear strength were(63.98±4.08)N,and(2.63±0.25)N/mm2 in MgHA group,while those in HA group were(41.44±7.07)N,(2.22±0.33)N/mm2.In addition,bone volume fraction,trabecular thickness,trabecular number,trabecular separation,connectivity density,and osseointegration rate in MgHA group were(24.5±6.1)%,(80.6±11.9)μm,(5.8±0.5)mm-1,(194.7±38.2)μm,(51.9±5.6)mm-3,(58.6±6.2)%,while those in HA group were(16.6±4.3)%,(68.4±10.3)μm、(5.2±0.6)mm-1、(220.8±30.6)μm、(44.1±4.5)mm-3、(45.1±3.8)%.All the differences were statistically significant(P<0.05) except trabecular separation.Conclusions Magnesium element can improve biological performance of implants in osteoporosis bone.