EFFECT OF FLUORIDE NUCLEATION ON GLASS-CERAMIC FORMATION

各种形式的磷酸钙陶瓷的生物相容性， 在文献中有很好的记载。 它的类羟基磷灰石 组合物使其作为潜在的骨和/或牙齿特别有吸引力 替换材料。 这些陶瓷，像所有传统陶瓷一样， 表现出低的拉伸强度，这限制了它们的应用。 微晶玻璃技术已被用于生产细颗粒钙 高强度磷酸盐陶瓷，硬度值与搪瓷相似， 对柠檬酸的耐化学性比牙釉质好。 的 玻璃陶瓷工艺具有特殊的特性， 应用。 由于该材料起源于玻璃，因此它具有 可能被铸造并且可能容易地结合到金属上， 熔化状态的玻璃会“润湿”其他材料。 含有少量第三组分的磷酸钙玻璃可 形成玻璃陶瓷。 氧化铝已被报道为成核剂， 磷酸钙微晶玻璃生产中的助剂。 氟是一 在许多玻璃-陶瓷系统中常用的成核剂。 拟议 研究项目旨在获得特定的热，化学和 氧化铝组成范围的机械性能数据， 氟化钙成核磷酸钙微晶玻璃。 该提案将试图解决两个核心问题。 首先， 与氧化铝成核剂相反，氟化物的使用改善了 或降低所述材料的某些物理、化学和机械性能， 产生的玻璃陶瓷？ 其次，做粘性和热膨胀 容易实现的玻璃-金属密封的性能？ 的应用 这种技术既可用于种植体，也可用于牙冠和牙桥的制作， 在这些领域改进现有技术的潜力。

The Biocompatibility of Calcium Phosphate Ceramics, in various forms, have been well documented in the literature. Its hydroxyapatite-like composition makes it especially attractive as a potential bone and/or tooth replacement material. These ceramics, like all conventional ceramics, exhibit low tensile strength which limits their use. Glass-ceramic techniques have been used to produce fine grained calcium phosphate ceramics of high strength, a hardness value similar to enamel and better chemical resistance to citric acid than tooth enamel. The glass-ceramic process has special characteristics which allow new processes to be applied. Since the material originates as a glass, it has the potential to be cast and perhaps easily bonded to metal based on the fact that glass in its molten state will "wet" other materials. Calcium phosphate glasses containing small amounts of a third component can form a glass-ceramic. Alumina-oxide has been reported as a nucleating agent in the production of calcium phosphate glass-ceramics. Fluoride is a commonly used nucleating agent in many glass-ceramic systems. The proposed research project is designed to obtain specific thermal, chemical and mechanical property data on a compositional range of alumina-oxide and calcium fluoride nucleated calcium phosphate glass-ceramics. This proposal will attempt to address two central questions. First, does the use of fluoride as opposed to alumina-oxide nucleating agents improve or diminish certain physical, chemical and mechanical properties of the resulting glass-ceramic? Secondly, do the viscous and thermal expansion properties of an easily achievable glass-metal seal? The application of this technique to both implant and crown and bridge fabrication offers the potential to improve current technology in these areas.