Effect of Divided Dosage of rhBMP-2 on Bone Healing in Rat Calvarial Bony Defect
Soo-Woon LEE*,Seo-Jeong Hyun
Department of Oral and Maxillofacial surgery, Haeundae Paik hospital, Inje University
Purpose: To assess the effect of rhBMP-2 on bone healing when we applied the same dosage at one time and three times on time schedule. We hypothesized that using same dosage of rhBMP-2 in three times on time schedule have better bone healing effect compare to use it at one time.
Material and methods: Twenty eight Sprague-Dawley male rats were randomly divided into three groups: control group(4N): one time applied group(12N): three times applied group(12N). 5mm diameter bony defect were made on one side of frontal bone, and collagen sponge were prepared socked with 30µ° PBS only(control), 30µ° PBS including 2µg (one time applied group) or 30µ° PBS including 0.7µg (three time applied group),respectively then applied. After 2,and 4 day operation, rat of three times applied group were injected into bony defect on frontal bone with 30µ° PBS including 0.7µg rhBMP-2. Rats were euthanized 1,2,3,4 weeks interval , bone and periosteum was harvested.
Radiologic, histologic, histomorphometric, and immunohistochemical analysis were done.
Results: Compare to one time applied group, three times applied group have different healing pattern. At 1 week, three times applied group showed less new bone formation compare to one time applied group. At 2, 3 weeks, slightly over growing woven bone healing was shown in three times applied group. At 4 weeks, three times applied group showed more maturation to neighboring bone compare to one time applied group.
Conclusion: When we applied the rhBMP-2 on bone defect, serial apply would be one method for new bone formation and further study would be needed to the optimal concentration on clinical use.
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