Primary alveolar cleft repair has a 41 to 73 percent success rate. Patients with persistent alveolar defects require secondary bone grafting. The authors investigated scaffold-based therapies designed to augment the success of alveolar repair.
Critical-size, 7 × 4 × 3-mm alveolar defects were created surgically in 60 Sprague-Dawley rats. Four scaffold treatment arms were tested: absorbable collagen sponge, absorbable collagen sponge plus recombinant human bone morphogenetic protein-2 (rhBMP-2), hydroxyapatite–tricalcium phosphate, hydroxyapatite–tricalcium phosphate plus rhBMP-2, and no scaffold. New bone formation was assessed radiomorphometrically and histomorphometrically at 4, 8, and 12 weeks.
Radiomorphometrically, untreated animals formed 43 ± 6 percent, 53 ± 8 percent, and 48 ± 3 percent new bone at 4, 8, and 12 weeks, respectively. Animals treated with absorbable collagen sponge formed 50 ± 6 percent, 79 ± 9 percent, and 69 ± 7 percent new bone, respectively. Absorbable collagen sponge plus rhBMP-2–treated animals formed 49 ± 2 percent, 71 ± 6 percent, and 66 ± 7 percent new bone, respectively. Hydroxyapatite–tricalcium phosphate treatment stimulated 69 ± 12 percent, 86 ± 3 percent (p < 0.05), and 87 ± 14 percent new bone, respectively. Histomorphometry demonstrated an increase in bone formation in animals treated with hydroxyapatite–tricalcium phosphate plus rhBMP-2 (p < 0.05; 4 weeks) compared with empty scaffold.
Radiomorphometrically, absorbable collagen sponge and hydroxyapatite–tricalcium phosphate scaffolds induced more bone formation than untreated controls. The rhBMP-2 added a small but significant histomorphometric osteogenic advantage to the hydroxyapatite–tricalcium phosphate scaffold.
New York, N.Y.
From the Institute of Reconstructive Plastic Surgery, New York University School of Medicine, and the Department of Biomaterials and Biomimetics, New York University College of Dentistry.
Received for publication December 19, 2008; accepted June 10, 2009.
Disclosure:To the best of the authors' knowledge, no financial support or benefits have been received by any coauthor, by any member of their immediate families, or by any individual or entity with whom or with which they have a significant relationship from any commercial source that is related directly or indirectly to the work reported in the article.
Absorbable collagen sponges, HA-TCP scaffolds, and rhBMP-2 were provided (free of charge) by Medtronic, Inc. (Memphis, Tenn.).
Stephen M. Warren, M.D.; Institute of Reconstructive Plastic Surgery; New York University School of Medicine; 560 First Avenue, TH-169; New York, N.Y. 10016; firstname.lastname@example.org