Cyclosporine-a and bone density around titanium implants: a histometric study in rabbits

Aim Cyclosporine A (CsA) is an immunosuppressive agent common- ly used to prevent organ transplantation rejection. It has been demonstrated that CsA may negatively affect osseointegration around dental implants. Therefore, the aim of this study was to eva- luate the effect of CsA administration on bone density around tita- nium dental implants. Materials and Methods Fourteen New Zealand rabbits were ran- domly divided into 2 groups with seven animals each. The test group (CsA) received daily subcutaneous injection of CsA (10mg/kg body weight) and the control group (CTL) received saline solution by the same route of administration. Three days after the beginning of immunosuppressive therapy, one machined dental implant (7.00 mm in lenght and 3.75 mm in diameter) was inserted bilaterally at the region of the tibial methaphysis. After 4 and 8 weeks the animals were sacrificed and the histometrical procedures were performed to analy- se the bone density around the first four threads of the coronal part of the implant. Results A significant increase in the bone density was observed from the 4- to the 8 week-period in the control group (37.41% + 14.85 versus 58.23% + 16.38 - p < 0.01). In contrast, bone density con- sistently decreased in the test group overtime (46.31% + 17.38 ver- sus 16.28 + 5.08 - p <0.05). In the 8-week period, there was a significant difference in bone density between the control and the test groups (58.23 + 16.38 eand16.28 + 5.08 - p= 0.001). Conclusion Within the limits of this study, long-term CsA admini- stration may reduce bone density around titanium dental implants during the osseointegration process.