The purpose of this study is to evaluate the efffect of the bone morphogenetic protein, bone matrix gelatin and collagen matrix on the amount and shape of generating new bone adjacent to the implant.
Implants were inserted in the mandible of adult dogs at 2 months after teeth extraction. Artificial bony defects, 3mm in width and 4mm in depth were made at the mesial and distal side of implant. Experimental groups were divided into three groups; Group 1 : Defects filled with collagen matrix and bone morphogenetic protein. Group 2; Defects filled with bone matrix gelatin, Control group: Defects filled with only collagen matrix.
After implantation, the animals were sacrificed at 1, 3, 5 and 10 weeks for light microscopic examination. For the fluorescent microscopic examination, each tetracycline Hcl and calcein were injected at 1, 3, 5, 8 and 10 weeks after implantation.
The results obtained were as follows:
1. The molecular weight of bovine BMP was about 18,100 by hydroxyapatite chromatography.
2. Osseointegration was observed in experimental groups 1 & 2, and BMG and BMP had an excellent bone forming capability as a filling materials to the repair of the bone defects.
3. The degree of healing of bone defect area, the experimental group 1 showed more prominent bone formation than control group, and the control group showed fibrous connective tissue between the implant and the bone.
4. In the fluorescent microscopic findings, bone remodelling was observed regenerative lamellar bone at defect area in experimental group 1, and partial remodelling in experiment group 2. In the control group, fibrous connective tissue was observed between the implant and bone surface and sign of remodelling was not appeared.
Above results suggest that BMP has rapid osteoinductive property and can be used clinically as a bone substitute on bone defects around implants.
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