晶化温度对齿科用微晶玻璃物理性能的影响

Influences of crystallization temperature on physical properties of mica-based glass-ceramics for dental restorations

根据齿科CAD/CAM加工用修复材料的要求 ,采用K2 O MgO MgF2 SiO2 微晶玻璃系统 ,通过差热分析 (DTA)、X射线衍射分析 (XRD)、扫描电子显微镜 (SEM )观测及物理性能测试 ,研究了 3种不同晶化温度对四硅氟云母微晶玻璃的晶化特性、微观结构及物理性能的影响。研究结果表明 ,随着晶化温度的逐步升高 ,四硅氟云母晶粒尺寸和径厚比逐步增大 ,抗弯强度和断裂韧性亦逐渐增高 ,维氏硬度和脆性指数随温度升高而降低 ;而提高晶化温度对密度无明显影响。

According to the requirements of dental restorative materials. K2-MgO-MgF2-SiO2 glass-ceramics system was chosen to make a machinable tetrasilicic fluormica glass-ceramics used for dental CAD/CAM restorations and the influences of three different crystallization temperatures on it's physical properties were investigated. Differential thermal analysis (DTA), X-ray diffractometer (XRD) and scanning electron microscopy (SEM) were sued to observe the crystallization behavior, crystal phases and microstructures of the glass-ceramics. Physical properties of the glass-ceramics were compared. The results show that improving crystallization temperature can increase the grain sizes of the mica and improve the three-point bending strength and fracture toughness of the glass-ceramics. Vickers hardness and the index of brittleness decrease with increasing of temperature, but density is not affected by temperature changes.