二次熔融烧结法制备牙科用可切削云母基玻璃陶瓷

Fabrication of dental machinable mica base glass-ceramics with incorporation and sintering

目的:通过二次熔融烧结法制备以云母为主晶相的牙科用可切削玻璃陶瓷。方法:在1500℃下熔融K2O-MgO-Al2O3-SiO2-F系统基础玻璃,其玻璃粉经过冷等静压成型后无压烧结获得牙科用可切削玻璃陶瓷。采用DTA-TGA确定基础玻璃的核化和晶化温度,采用XRD和SEM分析烧结体的物相组成和微观形貌,以及采用三点弯曲法和压痕法测定烧结体的力学性能。结果:K2O-MgO-Al2O3-SiO2-F系统的核化温度和晶化温度分别选择680℃和1020℃。烧结体的整体析晶比较缓慢,结晶度约为35.48%,主晶相为氟硅云母,晶体呈立方或扁平状,交错排列。烧结体的弯曲强度和断裂韧性分别为(144.50±9.75)MPa和(1.25±0.26)MPa.m1/2。结论:二次熔融烧结法制备的云母基玻璃陶瓷能够满足临床牙体缺损修复的要求。

AIM： To fabricate machinable mica glass - ceramics with incorporation and sintering for dental restorations. METHODS： K2O-MgO-Al2O3-SiO2-F system was chosen to be melted for the base glass at 1500℃, and the glass biscuit was formed with cold isostatic pressing, and then was sintered for dental machinable mica base glass - ceramics. The nucleation and crystallization temperatures of this system were determined with differential thermal analysis （DTA） and thermal gravimetric analysis （TGA）. The sintered body was analysed with X -ray diffrac- tion （XRD） to determine the crystalline phases. The microstructure of the sintered body was investigated with scanning electron microscopy （SEM）. Then mechanical properties of the sintered body were detected. RESULTS： The nuclea- tion and crystallization temperatures of K2O-MgO-Al2O3-SiO2-F system were 680℃ and 1020℃. The crystalliza- tion of the sintered body was slow and the crystalline rate was 35.48%. The main crystalline phases were fluorosilicic mica, which consisted of cubic or plate crystal, arranged interlacedly. The flexible strength of the sintered body reached 144.50±9.75MPa, and its fracture toughness was 1.25 ±0.26 MPa ·ml/2. CONCLUTION： The sintered body can satisfy requirements of the clinical restorations for tooth defect.