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

本研究的目的是开发新的外科和牙科用磷酸钙玻璃陶瓷，并检查它们在植入时的生物相容性。研制了两种微晶玻璃，一种是以磷酸钙为主的CaO-P_2 O_5系定向晶化微晶玻璃，另一种是以磷酸钙为主的无规晶化微晶玻璃。（一）.定向晶化微晶玻璃具有高抗弯强度和高韧性，与天然骨结合良好。我们认为，骨植入材料应具有与天然骨接近的低杨氏模量，从这一点来看，单向结晶微晶玻璃是优选的。然而，它们的缺点在于，化学耐久性不是很高，机械强度不会随着时间的增加而降低。（二）、CaO-Al_2 O_3-P_2O_5系统和CaO-TiO_2-P_2O_5系统的随机晶化微晶玻璃，从熔融状态浇铸时，具有高的可铸性（可成形性）。这些都是适用于人工牙冠材料，因为它的高成型性，高机械强度，以及高化学耐久性。采用酸性Na_2 O-CaO-TiO_2-P_2O_5系统微晶玻璃，通过溶出法制备了微孔微晶玻璃。（三）、生物相容性已被医学研究人员检查的钙磷酸盐玻璃陶瓷。

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.