Experimental Study On Repair Of Mandible Defects By Basic Fibroblast Growth Factor Combined With Partly Demineralized Xenogeneic Bone In Rabbits

[Objective] The present study was designed to investigate the osteogenetic effect and the level of vascular endothelial growth factor (VEGF) expression in repairing mandible defects in rabbits with bone graft, which was constructed by basic fibroblast growth factor (bFGF) of different concentration and partly demineralized xenogeneic bone (PDXB), to analysis the correlation among the concentration of bFGF, the amount of newly formed bone and the level of VEGF protein expression; at the same time, to explore the repair mechanism of bFGF combined with PDXB that warrants further clinical investigation.[Methods] 15mm×5mm bilateral mandibular periosteum bone defects were made surgically in 66 New Zealand adult rabbits. All the animals were divided into 6 groups randomly. Four groups (the group I～IV) of 96 defects each were grafted with bFGF of different concentration (0.1～100ng/mm~3) reconstituted in PDXB. The group V of 12 rabbits (24 defects) each was grafted with autogenous mandibular bone and PDXB in bilateral defects randomly. The group VI of 6 rabbits (12 defects) each was grafted with nothing as the control. 22 animals each were sacrificed 2 , 4, and 8 weeks after surgery respectively and the specimens were harvested and processed for histological and immunohistochemical examinations. The amount of newly formed bone and the percentage of VEGF positive staining area were quantified by image analysis. Then the correlation between levels of VEGF production and the amounts of newly formed bone was also analyzed by using statistics software.[Results] (1) Gross and histological observation showed that the major osteogenetic pattern was "creeping substitute" in the implant of the group V (grafted with PDXB alone), and was both osteoconduction and osteoinduction in that of the group I～IV (grafted with PDXB/bFGF). (2) Quantitative analysis by using Masson staining...