Tibolone, alendronate, and simvastatin enhance implant osseointegration in a preclinical in vivo model

Objectives: The objective of the study was to evaluate and compare the effect of different drugs such as simvastatin, alendronate, and tibolone for titanium implant osseointegration enhancement.

Materials and methods: Eighty female albino Wistar rats were equally divided into five groups: Group I (ovariectomy), Group II (sham ovariectomy), Group III (alendronate + ovariectomy), Group IV (simvastatin + ovariectomy), and Group V (tibolone + ovariectomy). Three months after ovariectomy, we performed bilateral titanium intramedullary nailing in all groups, followed by oral administration of alendronate, simvastatin, or tibolone for 12 weeks. Examinations included micro-CT, mechanical pull-out test, histology, and bone serum markers.

Results: Peri-implant micro-CT analysis showed a significantly higher overall bone tissue in tibolone compared to the ovariectomy group, while no significant difference was found between the treatment groups. Sham ovariectomy, alendronate, and tibolone groups had a higher body mass density compared to ovariectomy and simvastatin groups. All treatment groups had a greater thickness of the peri-implant compact bone layer compared to ovariectomy group, but the results were not statistically significant. Tibolone presented the highest values in pull-out test, but alendronate showed more consistently positive results compared to Other groups. Osteocalcin had in the tibolone group almost three times the value in the ovariectomy group, but the results were not statistically significant.

Conclusion: The hypothesis that alendronate, simvastatin, and tibolone enhance the osseointegration process of intramedullary titanium implants in ovariectomized rats has been accepted, while tibolone could offer the best results.