Short-term immunosuppressive therapy does not affect the density of the pre-existing bone around titanium implants placed in rabbits

Abstract

The aim of this study was to evaluate the influence of the administration and withdrawal of cyclosporin A/nifedipine on the bone density in a lateral area adjacent to implants placed in rabbits. Two screw-type titanium implants were placed bilaterally in twenty-eight New Zealand rabbits. The animals were assigned to one of the following groups and received daily subcutaneous injections for 14 days: Groups A and C: vehicle (dimethyl sulfoxide); Groups B and D: CsA (10 mg/kg) plus nifedipine (50 mg/kg). The animals in Groups A and B were sacrificed 14 days postoperatively and, in Groups C and D, 42 days postoperatively. After sacrifice, the tibiae were removed and undecalcified sections were obtained. Bone density was obtained in a 500 mm-wide zone lateral to the implant surface. Intergroup analysis showed no significant difference (p > 0.05) in the degree of bone density between control and test groups either on day 14 or on day 42. Thus, it appears that a short-term immunosuppressive therapy may not present a negative influence on the density of the pre-existing bone around titanium implants placed in rabbits.

Effect of the long-term administration of Cyclosporine A on bone healing around osseointegrated titanium implants: A histomorphometric study in the rabbit tibia

“…CsA therapy may affect bone healing due to its mechanism of action. T‐lymphocytes are the main target of CsA administration, and previous study (Duarte et al, ) in rats showed that T cells perturbations are associated with the development of primary osteoporosis. In this context, the immune system dynamically contributes in bone mineral metabolism and T‐lymphocytes play a pivotal role in the development of CsA‐induced osteopenia (Duarte et al, ).…”

“…T‐lymphocytes are the main target of CsA administration, and previous study (Duarte et al, ) in rats showed that T cells perturbations are associated with the development of primary osteoporosis. In this context, the immune system dynamically contributes in bone mineral metabolism and T‐lymphocytes play a pivotal role in the development of CsA‐induced osteopenia (Duarte et al, ). T cell suppression leads to a high metabolism state, in which bone turnover is increased resulting in elevated bone resorption rate compared to the bone formation, and subsequently a lower percentage of trabecular bone volume and development are achieved (Duarte et al, ; Movsowitz et al, ).…”

“…CsA therapy may affect bone healing due to its mechanism of action. T-lymphocytes are the main target of CsA administration, and previous study (Duarte et al, 2003b) in rats showed that T cells perturbations are associated with the development of primary osteoporosis.…”

“…In this context, the immune system dynamically contributes in bone mineral metabolism and T-lymphocytes play a pivotal role in the development of CsA-induced osteopenia (Duarte et al, 2003b). T cell suppression leads to a high metabolism state, in which bone turnover is increased resulting in elevated bone resorption rate compared to the bone formation, and subsequently a lower percentage of trabecular bone volume and development are achieved (Duarte et al, 2003b;Movsowitz et al, 1988Movsowitz et al, , 1989. Although the effects of CsA on bone metabolism have been described for more than a decade, the exact mechanism of action of this drug remains largely unknown (Duarte et al, 2001;Faulds et al, 1993;Sakakura et al, 2003Sakakura et al, , 2006Sakakura et al, , 2007.…”

“…Experimental data that investigate and compare the effects of CsA therapy on bone healing after implant osseointegration are scarce (Duarte, Nogueira Filho, Sallum, Sallum, & Nociti Junior, 2003b;Sakakura et al, 2003). Here, continuing our pre-clinical studies evaluating the influence of immunosuppressive agents on bone metabolism, we sought to investigate the effect of CsA therapy on bone healing around titanium implants with established osseointegration in the rabbit tibia by means of descriptive histologic and histomorphometric analyses.…”