Tissue reactions to titanium implants containing bovine bone morphogenetic protein: a scanning electron microscopic investigation.

Cylindric titanium implants treated with bovine bone morphogenetic protein (bBMP) (Group I) and with bovine serum albumin (BSA) (Group II) were implanted in the edentulous mandibles of 15 adult dogs. They were examined 1, 2, 4, 8, and 12 weeks after insertion of the implants by scanning electron microscopy (SEM). In all specimens from Group I, active bone formation had occurred between the implant and host bone, with a well-adapted fit between the implant and the newly formed bone 4 weeks after implantation. The surrounding bone was of normal structure by week 8. However, 3 months after implantation, fibrous tissue was consistently seen surrounding parts of the implants in Group II. The results of this study suggest that the implants treated with bBMP are capable of forming new bone of normal structure at a faster rate than BSA controls and that this new bone is closely adapted to the implant surface.