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

本研究的目的是开发用于外科和牙科的新型磷酸钙微晶玻璃，并研究它们在植入时的生物相容性。目前已开发出两种微晶玻璃；一种是单向结晶的CaO-P_2O_5微晶玻璃，另一种是以磷酸钙为主的随机结晶微晶玻璃。单向结晶微晶玻璃具有高抗弯强度和高韧性，与天然骨结合性能好。我们认为骨种植材料应具有接近天然骨的低杨氏模量；从这个角度来看，单向结晶的微晶玻璃是更可取的。然而，它们的缺点是化学耐久性不高，机械强度随时间的增加而降低。在CAO-A1_2O_3-P_2O_5和CaO-TiO_2-P_2O_5体系中随机结晶的微晶玻璃在熔融状态下浇注时具有较高的精密浇注性（成型性）。这些都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。用na22o - cao - tio_2 - p_2o_5酸浸法制备微孔微晶玻璃(3)。医学研究人员对磷酸钙微晶玻璃的生物相容性进行了研究。

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.