Abstract: Objective: Through the establishment of a simple model of bone defect, the complex of escoral hydroxyapatite(CHA)and platelet rich fibrin(PRF), the complex of coral hydroxyapatite and autogenous bone, the complex of coralline hydroxyapatite and recombinant human bone morphogenetic protein-two (rhBMP-2) and pure coral hydroxyapatite, four types of bone graft materials were implanted into four same bone defect areas. Then the ability of bone defect repair was compared between the four groups of bone graft materials in early different stages. Methods: Four bone defect areas were prepared in the six beagle dogs of canine bilateral tibial metaphyseal and were implanted with PRF/CHA, autogenous bone/CHA, rhBMP-2/CHA and CHA. The neck subcutaneou of six beagle dogs was injected with tetrac- ycline rochloride, calcein, alizarin red after second, fourth and eighth week, The six beagle dogs were executed and drawn after twelfth week, then bone growth condition of four bone graft areas was observed by gross specimen, hard tissue slices were made to compare the new bone formation in different bone graft area at different time by measuring fluorescence labeling rate. Results: Four groups of bone defect areas were completely closed in the gross specimen and there was no significant difference between the four groups of bone defect areas. Hard tissue slices observation result:four groups of bone defect areas showed orange fluorescence band after second week,namely new bone was found, the quantity of new bone:autogenous bone/CHA group>PRF/CHA group≈rhBMP-2/CHA group>CHA group, the green fluorescence band was increased significantly after second to fourth week, namely osteogenic ability was enhanced, the quantity of new bone:autogenous bone/CHA group>PRF/CHA group≈rhBMP-2/CHA group>CHA group, the four groups of bone defect areas showed red fluorescence after fourth to eighth week, the quantity of new bone:PRF/CHA group>autogenous bone/CHA group>rhBMP-2/CHA group>CHA group. Conclusion: During the twelve weeks, the osteogenesis effects of three kinds of composite bone graft materials were significantly better than that the pure coral hydroxyapatite, In the early stage, the quantity of new bone of three groups of composite bone graft materials were different in different time and autogenous bone/CHA group was best, PRF/CHA group was better than rhBMP-2/CHA group, after second week of operation, new bone was found in four groups of bone defect areas, the longer,the more of the quantity of new bone.

Key words: bone defect repair, composite bone graft material, fluorescence mark rate, bone growth factor