两种牙科切削陶瓷材料可切削性的比较

Comparison of machinability of two types of dental machinable ceramic

目的 对作者研制的一种新型含钙云母玻璃陶瓷PMC Ⅰ型陶瓷的可切削性能与VitaMKⅡ陶瓷进行定量比较 ,探讨PMC Ⅰ型陶瓷强度与其可切削性的关系。方法 采用钻孔实验方法 ,测定A、B、C、D4组不同晶化处理的PMC Ⅰ型陶瓷及VitaMKⅡ陶瓷材料 60 0s的钻孔深度 ,同时测定4组PMC Ⅰ型陶瓷的 3点抗弯强度。结果 VitaMKⅡ的钻孔深度为 0 71mm ;4组PMC Ⅰ型陶瓷的钻孔深度分别为 0 88mm、1 40mm、0 40mm和 0 90mm。其中 ,B组样品与其余组别及VitaMKⅡ陶瓷的差异有显著性 (P <0 0 5)。 4组PMC Ⅰ型陶瓷的 3点抗弯强度分别为 1 37 7、2 1 0 2、1 1 8 0和 1 0 6 0MPa。结论 新型PMC

Objective In terms of the problems of now available dental machinable ceramics, a new type of calcium mica glass ceramic, PMC Ⅰ ceramic, was developed, and its machinability was compared with that of Vita MKII quantitatively. Moreover, the relationship between the strength and the machinability of PMC Ⅰ ceramic was studied. Methods Samples of PMC Ⅰ ceramic were divided into four groups according to their nucleation procedures. 600 seconds drilling tests were conducted with high speed steel tools(Φ=2 3 mm) to measure the drilling depths of Vita MKII ceramic and PMC Ⅰ ceramic, while constant drilling speed of 600 rpm and constant axial load of 39 2 N were used. And the 3 point bending strength of the four groups of PMC Ⅰ ceramic were recorded.Results Drilling depth of Vita MKII was 0 71 mm, while the depths of the four groups of PMC Ⅰ ceramic were 0 88 mm?1 40 mm?0.40 mm and 0 90 mm, respectively. Group B of PMC Ⅰ ceramic showed the largest depth of 1 40 mm and was statistically different from other groups and Vita MKII. And the strength of the four groups of PMC Ⅰ ceramic were 137 7?210 2?118 0 and 106 0 MPa, respectively.Conclusion The machinability of the new developed dental machinable ceramic of PMC Ⅰ could meet the need of the clinic.