Bone regeneration in the rat mandible with bone morphogenetic protein-2: a comparison of two carriers.

OBJECTIVE: To compare mandibular bone regeneration with bone morphogenetic protein-2 (BMP-2) delivered with two carriers: a hyaluronic acid polymer (HY), and a collagen carrier complexed with calcium hydroxyapatite and tricalcium phosphate (collagen/HA/TCP). STUDY DESIGN: Defects were created in the bilateral mandibular bodies of 16 Sprague-Dawley rats. The defects were filled with the HY carrier, the HY carrier loaded with BMP-2, the collagen/HA/TCP carrier, or the collagen/HA/TCP carrier loaded with BMP-2. Animals were euthanatized after 6 weeks, and the hemi-mandibles were analyzed histomorphologically. RESULTS: Specimens containing BMP-2 had significantly larger new bone and marrow volumes than control specimens. Specimens in the hyaluronan/BMP-2 group tended to have larger volumes of new bone and osteoid than collagen/HA/TCP/BMP-2 specimens, though these differences were not statistically significant. CONCLUSION: The HY and collagen/HA/TCP carriers had comparable efficacy for bone healing with BMP-2. SIGNIFICANCE: Bone morphogenetic proteins can be delivered with commercially available alloplasts as osteogenic bone substitutes for the repair of craniofacial bone defects. EBM rating: B-2.