In order to evaluate coral as a bone graft substitute in repair of bone defect, particulates of coral were implanted into skull bone defect of rabbit, 1.5 cm in diameter. Hydroxyapatite and blank were taken as controls. The rabbits were sacrificed at the second, fourth, eighth and twelveth weeks after the operation. The specimens were taken and performed histological examination and histomorphometry observation. Results were as follows: at the second week many multinucleus giant cells infiltrated. As time elapsed, the coral were progressively degenerated and new bone was formed to fill the defect. Up to the twelveth week, the coral degenerated completely and new bone formed in the center of the defect. Percentage of new bone was in defect was 36.9%. Compared with the controls, there were significant differences (P lt; 0.01). It was suggested that coral had good osteoconductility. Howevel, coral underwent rapid degeneration, it might result in inconplete repair of bone defect.
