热铸型陶瓷包埋料的研制和铸造精度的检测

The study of a special investment used for the heat pressed ceramics

目的 :根据新型热铸型玻璃陶瓷的性能 ,研制出专用包埋材料 ,并对其性能和铸造精度进行检测。方法 :通过组分筛选和工艺合成得出优选配方 ,对包埋料的物理性能进行检测 ;并用研制的包埋料铸造陶瓷全冠 ,用片切法观察代型与全冠之间的粘固膜厚度。结果 :热铸型陶瓷包埋料为石英磷酸盐包埋料 ,凝固时间 8.5 -9min ,凝固膨胀率 2h后为 0 .5 8% ,80 0℃热膨胀率为 0 .78% ,总膨胀率为 1.3 6% ,抗压强度 2 4h后 2 9MPa ,80 0℃焙烧后为 17MPa。代型与陶瓷全冠之间的粘固膜厚度 ,与对照组之间无显著性差异 (P >0 .0 5 )。结论 :热铸型陶瓷专用包埋料具有适宜的凝固时间、膨胀率及抗压强度 ,能够制作出适合性良好的陶瓷修复体。

Objective:The purpose of this study was to form a special phosphate bonded investment which was used for the heat pressed glass ceramics.Method:The new investment was formed according to the component analysis and selection and then its mechanical properties and casting accuracy were tested.Result:The setting time was 8.5～9min,the setting expansion was 0.58%,thermal expansion was 0.78%,the total expansion was 1.36%.The compressive strength of the material was 29MPa(24h),17MPa(after heat in 800℃).The results of cement film thickness revealed there were no significant differences between the two groups.Conclusion:The new investment had exhibited the clinically acceptable setting time.setting and thermal expansion and compressive strength. The expansion of the new investment can compensate the shrinkage of the heat-pressed ceramics.