Abstract: Objective To study the effects of nano-hydroxyapatite（nHA） and collagen compound membrane on the repair of mandibular defects. Methods Put nHA and combine together to prepare nHA and collagen compound membrane. 20 healthy adult New Zealand rabbits were prepared rectangle bone defects of about 1.0 cm×0.5 cm×0.5 cm at middle part of bottom edge of both mandibles. The right side was the experimental one, whose defect was covered with nHA and collagen compound membrane. While the left group was sutured without any membrane. 28, 56 d after implantation, the effectiveness of bone formation was evaluated by means of X-ray observation and histological examination. Results nHA and complex group: New bone formation in the implanted defects were observed 28 d after operation, and the defects were replaced by mature bone tissue 56 d after operation and most of nHA and complex membrane was degra-ded. Blank contrast group: Fibrous tissue was found in the bone defects
8 weeks after operation. Conclusion nHA and collagen compound membrane may be feasible in the repair of bone defects.

Key words: collagen, nano-hydroxyapatite, bone defect