Ridge regeneration of damaged extraction sockets using rhBMP-2: an experimental study in canine.

OBJECTIVES: This study evaluated the dimensional ridge alteration in a buccal-bone-deficient extraction socket, and ridge regeneration following socket grafting accompanied by recombinant human bone morphogenetic protein 2 (rhBMP-2) or a collagen membrane covering. MATERIAL AND METHODS: In five beagle dogs, entire buccal bone of the extracted sockets of premolars was surgically removed and immediately grafted using one of the following graft protocols: (1) sham surgery without any grafting, and grafting with (2) deproteinized bovine bone mineral (DBBM), (3) DBBM/rhBMP-2 and (4) DBBM covered with a collagen membrane (DBBM/Membrane). Quantitative/qualitative analyses were performed radiographically/histologically after 8 weeks. RESULTS: Buccal-deficient extraction sockets healed with significant reduction in buccolingual dimension along the entire length of the socket, but all grafting techniques reduced the dimensional changes compared to the non-grafted control sites. Histologically, sites received DBBM only exhibited minimal regeneration, whereas sites grafted with DBBM/rhBMP-2 or DBBM/Membrane exhibited greater new bone formation extending the entire augmented area. CONCLUSIONS: Buccal-bone-deficiency may lead to significant volume reduction after tooth extraction along the entire length of the socket, and socket grafting accompanied by rhBMP-2 or covered with a membrane can be candidate therapies for preservation of the buccolingual dimension and successful ridge regeneration.