Abstract: Objective To study the possibility of using bFGFcollagen slow release system for repairing bone defect.Methods 60 Japanese white rabbits were randomly divided into three groups: the bFGF collagen sponge group,the collagen sponge group and the control group.Then the bone defects were made in the rabbits′ bilateral mandibles,and the biological materials corresponding with each group were inserted into defects.15 of animals were sacrificed at 2、6、8、12 weeks to be evaluated with anatomy,CT studies and histology.Results General observation and CT imaging showed a faster velocity of bone formation in the control groups.Histological observation showed that the effect of bone repairing in the experimental group was much better than that in the control group.The collagen in vivo lasted until 6 weeks ago,and the bFGF which was continuously released from it had obvious promoting effect on bone defect repair,while the action time was mainly 12 weeks ago.Conclusions The bFGFcollagen slow release system has great promoting effect on repairing rabbit mandibular defect,while the action time is mainly in the early stage of bone defect repairing.Besides,the collagen sponge itself also has promoting effect on mandibular defect repair.

Key words: basic fibroblast growth factor, collagen sponge, slow-release, critical size defect