晶化温度对牙科用云母微晶玻璃微观结构的影响

Influence of crystallization temperature on microstructures of mica-based glass-ceramics for dental restorations

目的 研究晶化温度对牙科 CAD/ CAM加工用四硅氟云母微晶玻璃微观结构的影响 .方法 选用 K2 O- Mg O-Mg F2 - Si O2 系统来制备云母微晶玻璃 ,通过差热分析 (DTA)、X射线衍射分析 (XRD)、扫描电子显微镜观测 (SEM)及三点弯曲强度的测试 ,比较了三种不同晶化温度对四硅氟云母微晶玻璃的晶化特性、微观结构及抗弯强度的影响 .结果 随着晶化温度的逐步升高 ,四硅氟云母晶粒的形态由球形转变为片层状 ,晶粒尺寸和径厚比逐步增大 ,微晶玻璃的抗弯强度也逐步升高 ,但其晶相组成未发生明显变化 .

AIM To investigate the influence of crystallization temperature on microstructures of mica based machinable glass ceramics used for CAD/CAM dental restorations. METHODS According to the requirements of dental restorative materials, K 2O MgO MgF 2 SiO 2 glass ceramics system was chosen to make tetrasilicic fluormica glass ceramics and three different temperatures were used to finish the crystallization procedure. Differential thermal analysis (DTA), X ray diffractometry (XRD) and scanning electron microscopy (SEM) were used to observe the crystallization behavior, crystalline phases and microstructures of the glass ceramics. Three point bending strength was also measured. RESULTS Grain shape changes from spherical to platelike as crystallization temperature went up. Improving crystallization temperature was increase the grain size, aspect ratio and flexural strength of the mica, while the crystalline phase is not affected by temperature changes. CONCLUSION Microstructures of the glass ceramics are determined by crystallization temperature.