REPAIR OF EXPERIMENTAL MANDIBULAR DEFECTS IN RATS WITH AUTOGENOUS, DEMINERALIZED, FROZEN AND FRESH BONE

This prospective experimental study aimed to assess the regenerative c apability of demineralised bone autografts resected and replaced ortho topically, compared with traditional fresh and deep frozen mandibular autografts in rats. In 60 adult Wistar rats, a bone defect 4 x 4 mm wa s created at the left ascending mandibular ramus and the removed bone was used as a fresh (n=20), deep frozen (n=20), or demineralised (n=20 ) graft which was implanted orthotopically 2 weeks later. Ten rats in each group were killed at 2 and 6 weeks later. Outcome was measured by cellular proliferation on histological examination. The number of mes enchymal cells was significantly greater (P<0.05) at both 2 and 6 week s in the demineralised grafts than in the other two groups. There were no differences between the 2- and 6-week examinations of deep frozen bone, nor between the medullary and peripheral aspects. It was conclud ed that demineralised bony autografts cause greater osteoinduction bot h in the short (2 weeks) and the medium (6 weeks) term.