Bone formation in the goat maxillary sinus induced by absorbable collagen sponge implants impregnated with recombinant human bone morphogenetic protein-2.

This study assessed the efficacy, safety, and technical feasibility of inducing bone formation in an animal model of maxillary sinus floor augmentation using recombinant human bone morphogenetic protein-2 (rhBMP-2) impregnated on an absorbable collagen sponge (ACS). Bilateral antral maxillary sinus floor elevation procedures were surgically performed in six adult female Alpine-Saanen goats. Bone formation in response to the implant was evaluated using sequential radiographs, computerized tomography, and gross pathologic and histologic analysis performed at necropsy. Computerized tomographic scans documented nonosseous radiopacity in both sinuses postimplantation. Sinuses implanted with the rhBMP-2/ACS subsequently demonstrated increasing radiopacity local to the implant site, while radiopacity of the negative control sinuses remained unchanged or decreased. The results demonstrated the ability of an rhBMP-2/ACS implant to induce substantive new bone formation within the maxillary sinus of goats without adverse sequelae. The rhBMP-2/ACS composite implant may represent an acceptable alternative to traditional bone grafts and bone substitutes for maxillary sinus floor augmentation procedures in humans.