Effect of Different Concentrations of Escherichia Coli-Derived rhBMP-2 Coating on Osseointegration of Implants in Dogs

The aim of the present study was to evaluate the effect of different concentrations of Escherichia coli-derived recombinant human BMP-2 (ErhBMP2) coating on osseointegration of implants (Cowellmedi, Pusan, Korea) in dogs. Three beagle dogs were used in this study. The lower premolars were extracted without causing bone destruction and cared for 8 weeks, which was considered as the bone healing period. The implants were coated with 4 different concentrations (0.1 mg/mL, 0.3 mg/mL, 0.5 mg/mL, and 1.0 mg/mL) of ErhBMP-2, and then installed in the extraction socket in the mandible and bone formation was assessed after 8 weeks. After the dogs were euthanized, histological samples were obtained and bone volume (BV) and bone-to-implant contact (BIC) were measured. The BV ratio was the highest in the ErhBMP-2 0.3 mg/mL group; however, the differences in the BV ratio between the treatment groups were not statistically significant. The level of BIC was higher in the ErhBMP-2 1.0 mg/mL group and the ErhBMP-2 0.3 mg/mL group than that in the other groups, but again the differences in the levels of BIC were not statistically significant. In addition, the level of BIC at all sites was relatively lower when compared to that in the previous studies. In this study, the ErhBMP-2 coating on the implants was not found to be useful for improving BV and BIC in the healthy alveolar bone. Further studies are needed to compare the level of BIC of the ErhBMP-2-coated implant and non-coated implant.