2003 Volume 28 Issue 1 Pages 16-26
It is well known that bone morphogenetic protein (BMP) encourages bone formation strongly. This study evaluated bone regeneration using rhBMP-2 in bone defects of the mandible. Bone defects 20 mm wide were surgically created in mandibular bones of adult male beagles and implants were placed into the bone defects. Experimental groups comprised a rhBMP-2 (+) group, a rhBMP-2 (-) group and a control group (no bone defects created). Animals were killed 12 weeks postoperatively, followed by quantitative, radiological and histological evaluations. Bone mineral measurement using dual energy X-ray absorptiometry (DEXA) revealed significant differences between the rhBMP-2 (+) group and, the rhBMP-2 (-) and control groups in bone mineral density (BMD) (p<0.01). Elementary analysis using particle induced X-ray emission (PIXE) revealed significant differences between the rhBMP-2 (+) group and, the rhBMP-2 (-) and control groups in concentrations of Mg and Ca (p<0.05, p<0.01). Using soft X-ray, the rhBMP-2 (+) group displayed better absorption of implants and new bone formation than the rhBMP-2 (-) group. Using microfocus X-ray CT, the rhBMP-2 (+) group displayed better absorption of implants, bone regeneration and internal structure of mandible than the rhBMP-2 (-) group. In histology, the rhBMP-2 (+) group displayed better absorption of implants and new bone formation than the rhBMP-2 (-) group. This study therefore suggested the utility of rhBMP-2 in bone regeneration.
