DEVELOPMENT OF FUNCTIONAL BIOMATERIALS APPLIED APATITE-COATING SYSTEM

本研究以构筑技术为基础，采用两步融合的方法将磷灰石包覆在金属表面，制备了具有良好强度和生物相容性的磷灰石-金属复合生物材料。首先，对磷灰石涂层人工牙根的形状设计进行三维有限元分析，以检验临床使用时人工牙根的理想形状。通过对磷灰石陶瓷断裂韧性、断裂机理和疲劳寿命预测的研究，阐明了磷灰石与金属结合时，磷灰石陶瓷韧性降低的严重问题。采用激光对等离子体熔合中出现劣化的磷灰石涂层进行了质量改善。此外，为了进一步提高生物相容性和韧性，扩大应用范围，尝试了磷灰石胶原蛋白的组合，并通过将磷灰石沉积在胶原纤维上的基础实验，证实了磷灰石与胶原蛋白的化学结合。实验结果表明，所制备的磷灰石-胶原复合物是一种可吸收的人工骨填充材料。另一方面，合成碳酸盐磷灰石，烧结制备可吸收磷灰石陶瓷。通过对其烧结性和溶解度的详细研究，制成了与天然骨磷灰石相似的试验产品，并通过动物成骨实验验证了其可作为骨填充材料。此外，通过人工体液浸渍检测成骨细胞对磷灰石包覆钛的早期粘附能力，证实在钛表面沉积磷灰石晶体可有效提高细胞粘附能力。

In this invesitigation, the apatite-metal composite biomaterials excellent for both strength and biocompatibility have been developed by coating the apatite on the metal surface using two step fusion method based on the build-up technique. Before everything, the ideal shapes of artificial tooth roots in clinical use were examined by carrying out the three dimensional finite element analysis for the shape design of apatite coating artficial tooth root. And from the study of fracture toughness, fracture mechanism and fatigue and life prediction of apatite ceramics, it was clarified that the lower value of toughness of apatiteceramics was serious problem in case of combining apatite with metal.The improvement in quality of apatite coating layr which has deteriorated in fusing by plasma has been performed using by laser light. Moreover, for expanding the application by more increase of both biocompatibility and toughness, the apatite collagen combination was attempted, and was comfirmed that the apatite would bonded chemically with collagen together, through the basic experiment made to deposit the apatite on the collagen fiber. The trial apatite-collagen complexes were tested by the experiment with animals, and was found to be usefull for an absorbable artficial bone filling material.On the other hand, the carbonate apatite was synthesized and sintered to develop the absobable apatite ceramics. By the investigation on sinterability and solubility in detail, the trial products similar to natural bone apatite were made, and was verified to be available for a bone filling material by bone formation experiment using animals.Furthermore, the early stage adhesiveness of osteoblast on apatite-coated titanium was examined by dipping into the artificial body fluid, it was confirmed that the ability of cell adhesion increased effectively by depositing the apatite crystal on the surface of titanium.