The effects of estrogen replacement therapy and local application of bisphosphonates on the implant osseointegration in ovariectomized rats / 实用口腔医学杂志

ABSTRACT

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 groupscontrol,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.