[Effect of alendronate sodium on torque-out testing on implant-bone interfaces in estrogen-deficient rabbits with alendronate systemic administration].

Objective: To investigate the influence of systemic application of Alendronate sodium, a bone resorption inhibitor, on the osseointegration of implant-bone interface in estrogen-deficient rabbits through mechanical assessment.

Methods: 27 five-month-old Japanese white female rabbits were randomly divided into three groups (9 rabbits each group). An ovariectomy group (OVX), an ovariectomy and Alendronate sodium group (ALN) and a shamed-operated group (S). 12 weeks after operation, implants were installed into bilateral distal femurs and proximal tibias in each group. Alendronate sodium was administrated by intraperitoneal injection in ALN group; meanwhile equivalent of normal saline was administrated by intraperitoneal injection in OVX group and S group. Bone mineral density was measured right after the implant operation and also in 4, 8, 12 weeks. Torque-out values were measured in 4, 8, 12 weeks after animal sacrifice.

Results: Bone mineral density of tibias in ALN group was closed to S group and was significantly different from OVX group (P < 0.05) after 8 weeks. While after 12 weeks, the bone mineral density of tibias and femurs in ALN group was both closed to S group and was significantly different from OVX group (P < 0.05). The torque-out values of tibias in ALN group were closed to S group and were significantly different from OVX group (P < 0.05) after 8 weeks. After 12 weeks, the torque-out values of tibias and femurs in ALN group were both closed to S group and were significantly different from OVX group (P < 0.05).

Conclusion: Systemic application of Alendronate sodium in osteoporosis rabbits can improve the bone-implant osseointegration significantly.