DEVELOPMENT OF FUNCTIONAL BIOMATERIALS APPLIED APATITE-COATING SYSTEM

本研究以堆积技术为基础，采用两步熔融法在金属表面包覆磷灰石，研制出强度和生物相容性优良的磷灰石-金属复合生物材料。通过对磷灰石涂层人工牙根的形状设计进行三维有限元分析，验证了临床应用中理想的人工牙根形态。通过对磷灰石陶瓷的断裂韧性、断裂机理、疲劳寿命预测等方面的研究，阐明了磷灰石与金属复合时，磷灰石陶瓷韧性值偏低是一个严重的问题。此外，为了更好地提高生物相容性和韧性，扩大了应用范围，尝试了磷灰石与胶原的结合，并通过在胶原纤维上沉积磷灰石的基础实验，证实了磷灰石与胶原具有化学结合作用。通过动物实验验证了实验用磷灰石-胶原复合体是一种可吸收的人工骨填充材料。另一方面，合成了碳酸盐磷灰石，并将其烧制成可吸收的磷灰石陶瓷。通过对其烧结性和溶解性的详细研究，制备了与天然骨磷灰石相似的实验产品，并通过动物成骨实验验证了其作为骨填充材料的可行性；此外，通过浸泡人工体液检测了成骨细胞在磷灰石涂层钛表面的早期粘附性，证实了通过在钛表面沉积磷灰石晶体可以有效地提高细胞粘附性。

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.