어골에서 추출한 천연 Hydroxylapatite(HAP-B)의 골친화성에 관한 실험적 연구 = An Experimental Study on Bone-Compatibility of Natural Hydroxylapatite(HAP-B) Extracted from Fish Bone

다국어 초록 (Multilingual Abstract)

There have been many ways to repair accidental, pathological or congenital bone befects. Autogenous bone graft has been frequently used for this purpose, but some disadvantages have made it necessary to develop synthetic implant materials.
Recently hydroxylapatite has been investigated intensively and reported many advantages. Though hydroxylapatite has been used widely, developed synthetic hydroxylatite is expensive.
The purpose of this study was to evaluate three types of hydroxylapatite extracted cheaply and easily from fish bone(HAP-B) as regards to tissue response, histocompatibility, aspect of bone formation and interface with bone.
The 28 rabbits, weighing about 2.0kg, were used as experimental animais and divided into 7 groups. Each group consisted of 2 units, which is composed of 2 rabbits. Among 2 rabbits of each experimental unit, the author prepared 4 intrabony defects of 6×4×3mm at both right and left sides of mandibular inferior border. The one intrabony defect was used as control which was not grafted at all, and the other 3 defects were grafted with three types of HAP-B.
At 4 days, 1, 2, 4, 8, 12 and 24weeks postoperatively, the animals were sacrificed, and were observed under light microscope and electron microscope following routine prepared processing.
The obtained results were as follows :
1. Inflammatory reaction was found in all of the experimental groups and control group at 4 days. But at 1 week, experimental groups showed no inflammatory reaction, no foreign body reaction, and showed osteoid tissue formation around the HAP -B. In control group, inflammatory reaction was still found and no osteoid tissue formation was found.
2. At 2 weeks, osteoblast lining on surface of new bone was found and more bone formation around HAP-B without connective tissue layer was observed, therefore both edges of bone defect began to connect each other early. In control group, bone formation was observed from the wall of bone defect, and no bone formation was found at central portion.
3. Until 2 weeks, bone fomation was active in the order of HAP -B(C), (A), and (B), but at 4weeks, more bone formation was observed, however no significant difference in activity of bone formation among HAP -B types was recognized.
4. After 4 weeks, bone defect was almost filled and repaired with HAP -B and new bone in experimental groups. But in control groups healed bony surface was slightly concave. No resorption of HAP -B was recognized until 24 weeks.
5. In transmission electron microscopic examination, at 1 week HAP -B was surrounded by amorphous layer with various width and collagen fiber, and then bone formation was occured gradually around the HAP-B, and the osteocyte of new bone was observed near the HAP-B at 2, 4 weeks. Amorphous layer showed a tendency to shrink after 1 week, and it appeared that HAP-B directly contacted with new bone at 8, 12 weeks, and slight bone growth into micropore of HAP-B was observed at 12 weeks.