Development and Its application of Calcium Phosphate Glass-Ceramics for biomaterials

本研究的目的是开发用于医疗和牙科的新型钙磷酸盐微晶玻璃，并检测其植入后的生物相容性。发展了两种微晶玻璃，一种是单向析晶的CaO-P_2O_5微晶玻璃，另一种是以磷酸钙为主的随机析晶微晶玻璃。单向晶化微晶玻璃具有高的抗弯强度和韧性，与天然骨具有良好的粘结性能。我们认为，骨植入材料的杨氏模数应接近于天然骨，从这个角度来看，单向晶化微晶玻璃是更好的选择。但它们的缺点是化学耐久性不高，机械强度不会随着时间的增加而降低。CaO-Al_2O_3-P_2O_5和CaO-TiO_2-P_2O_5系无定形微晶玻璃在熔融状态下浇注时具有较高的精密铸造性(可成型性)。这些材料具有高的可成形性、高的机械强度以及高的化学耐久性，适合用于人工牙冠材料。采用酸性Na_2O-CaO-TiO_2-P_2O_5微晶玻璃浸出法制备了微孔微晶玻璃。医学研究人员已经对磷酸钙微晶玻璃的生物相容性进行了测试。

The purpose of this investigation is to develop new calcium phosphate glass-ceramics for sugical and dental use, and to examine how they are biocompatible or not when implanted. Two kinds of glass-ceramics have been developed; one is unidirectionally crystallized CaO-P_2O_5 glass-ceramics, and the other is randomly crystallized glass-ceramics based on mainly calcium phosphate.(1). The unidirectionally crystallized glass-ceramics exhibit high bending strength and high toughness, and good bonding properties with natural bone. We believe that bone implant materials should have low Young's modulus as nearlly as natural bone's; from this view point, the unidirectionally crystallyzed glass-ceramics are to be preferable. However, they have weak points in that chemical durability is not so high to be decreased in mechanical strength with increasing time.(2). The randomly crystallized glass-ceramics in the system of CAO-A1_2O_3-P_2O_5 and CaO-TiO_2-P_2O_5 have high precise castability(shapability) when cast from the molten state. These are suitable for artificial dental crown materials, because of its high shapability, high mechanical strength,as well as high chemical durability. Micro-porous glass-ceramics have been developed by leaching with acid Na_2O-CaO-TiO_2-P_2O_5 glass-ceramics.(3). Biocompatibility has been examined for calcium phosphate glass-ceramics by medical researchers.