2013 年 10 巻 3 号 p. 123-130
The objective of this study was to assess the effects of vertical bone augmentation using a novel bone substitute. Porous composite uncalcined hydroxyapatite (u-HA; 70 wt%) and poly-DL-lactide (PDLLA; 30 wt%) blocks were grafted onto the cranial bone of 18 rabbits. Animals were sacrificed 1, 3, and 6 months after implantation. The molecular weight of PDLLA was measured and histological and histomorphometrical analyses were performed to evaluate new bone formation and material degradation. The molecular weight of PDLLA decreased significantly at each time-point. The blocks directly contacted with the original bone. New bone formation was observed whereas the block was gradually absorbed. Significantly more bone had been formed at 3 and 6 months than at 1 month. Similarly, bone height at 3 and 6 months was significantly greater than that at 1 month. The present study demonstrates that the u-HA/PDLLA block is biodegradable and osteogenic, suggesting that this material is a useful material for vertical bone augmentation.