| Objective: The influence of external basic fibroblast growth factor (bFGF or FGF-b) on the bone graft healing is investigated by establishing animal models of rat mandibula defects, which provides experimental basis of healing jaw defects through the combination of bFGF , Bio-oss bone and Bio-gide collagen membrane. Methods: 63 Wister rats, regardless of male or female, with the weight of about 450 g, are chosen and randomly divided into three groups —experimental group(30 rats), control group(30 rats) and blank control group(3 rats). Under the condition of total paralysis, the rat bone lamellas of left mandibular angle are exposed and a bone defect area of about 5mm×4mm×2mm is created. And get rid of the periosteum of the area . Every bone defect area represents a bone graft unit. In experimental group the Bio-oss bone covered with Bio-gide collagen membrane, and containing 1μg(40μg/ml ×25μl) recombinant rat fibroblast growth factor-basic(rRFGF-b) is planted in every bone graft unit. For control group, Bio-oss bone covered with Bio-gide collagen membrane, and containing 25μl physiological saline is planted in every bone graft unit. In blank control group no treatment is used in every bone defect area. The rats in the experimental and control groups are killed separately in the first week, second week, fourth week, sixth week and eighth week after operation, and the left mandibulas are collected as specimen. The rats except the ones which are killed in the first week after operation, are injected tetracycline hydrochloride twice in the abdomen 11 days before they are killed so as to be fluorescence labeled. The rats in the blank control group are killed in the eighth week after the operation, and the left mandibulas are collected as specimen. All the mandibula specimens are separately made into decalcifying paraffin sections and calcifying sclerous tissue sections and are tested through histology, fluorescence observation and bone histomorphometry. Results: Observation from histology shows that one week after operation, in control group the Bios-oss bone particles are surrounded by a lot of inflammatory corpuscles, osteoblasts can rarely be seen and no new bone can be formed. PCNA immunohistochemistry stain takes on weak positive. In experimental group,inflammatory corpuscles can rarely be seen around Bios-oss bone particles, but a lot of fibroblasts and osteoblasts can be seen with many new blood capillaries. New bone can't be seen, either. PCNA immunohistochemistry stain shows strong positive. Two weeks after operation, in control group a lot of phoroblasts and few osteoblasts exist around Bios-oss bone particles and new bones are rarely seen. PCNAimmunohistochemistry stain takes on weak positive. In experimental group, new bone lamellas with whole bone lacuna can be seen around the Bios-oss bone particles. A lot of osteoblasts and new blood capillaries exist between the particles. PCNA immunohistochemistry stain shows strong positive. Four weeks after operation, in control group, a good many osteoblasts and new blood capillaries can be seen around Bios-oss bone particles. Few new bone lamellas can be seen and PCNA immunohistochemistry stain shows middle positive. In experimental group new bone lamellas around the particles apparently increase, and begin to combine with each other. PCNA immunohistochemistry stain shows middle positive. Six weeks after operation, in control group no apparent changes are found and PCNA immunohistochemistry stain shows strong positive. In experimental group new bone lamellas become further wide and distributed more evenly. PCNA immunohistochemistry stain takes on weak positive. Eight weeks after operation, in control group, a good many osteoblasts and phoroblasts can be seen around Bios-oss bone particles. The number of new bone lamellas increased to munch extent and have combined with each other. PCNA immunohistochemistry stain shows middle positive. In experimental group Bios-oss bone particles are studded by new bone lamellas and Bios-oss bone particles start to be absorbed. The absorbing areas are replaced by new bone lamellas. PCNA immunohistochemistry stain nearly shows negative. In blank control group, a lot ofsurrounding inflammatory corpuscles can be seen, and osteoblasts and phoroblasts can be observed rarely , and no new bone can be detected. Observation of fluorescence microscope shows that two and four weeks after operation, the strength of tetracycline fluorescence and the width of double labeling line of bone graft areas in experimental group are both superior to those in control group. Six weeks after operation, the strength of tetracycline fluorescence and the width of double labeling line in both experimental and control group are equal. Eight weeks after operation, the strength of tetracycline fluorescence and the width of double labeling line in control group are superior to those in experimental group. Determination of bone histomorphometry shows that a week after operation the percentage of PCNA immunohistochemistry stain positive karyon in experimental group is much larger than that in control group (P<0.01). Two weeks after operation, new bone lamellas area in bone graft, the percentage of PCNA immunohistochemistry stain positive karyon and the amount of bone mineralization in experimental group are much higher than those in control group (P<0.05 or P<0.01). Four weeks after operation, new bone lamellas area in bone graft and the amount of bone mineralization in experimental group are much bigger than those in control group (P<0.05 or P<0.01 ). Otherwise, in the two groups the distinction of the percentage of PCNA immunohistochemistry stain positive karyon is inapparent (P>0.05). Six weeks after operation, new bone lamella area in...
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