The effect of a low dose of transforming growth factor β1 (TGF-β1) on the early bone-healing around oral implants inserted in trabecular bone

Transforming growth factor β1 (TGF-β1) has been shown to stimulate bone healing in several animal models and may influence bone response directly after implant installation. Aim of the present study is to investigate the effect of a low dose of TGF-β1, on the early bone-healing around oral implants placed in trabecular bone (femoral condyle of goats).Twenty-four cylindrical screw type implants were used and TGF-β1 in two different concentrations were applied on sixteen of them. Each animal received three implants: one Ti (control), one Ti loaded with 0.5 μg TGF-β1 (Ti-TGF0.5), and one Ti loaded with 1.0 μg TGF-β1 (Ti-TGF1.0). The eight animals were euthanized at 6 weeks after implantation and implants with surrounding tissue were retrieved for histological preparation and histomorphometrical evaluation. Light microscopical analysis showed the occurrence of an intervening fibrous tissue layer around about half of the TGF-β1 loaded implants. Further, the histomorphometrical measurements revealed that the Ti implants demonstrated the highest percentage of bone-implant contact (65 ± 4%), while Ti-TGF1.0 implants showed the lowest amount (45 ± 12%). The difference between these two groups was statistically significant. On basis of the results, it is concluded that a low dose of TGF-β1 has a negative effect on the integration of oral implants in trabecular bone during the early post-implantation healing phase.