纯钛冠桥铸造包埋料配方的确定

Study on investment of titanium crown and bridge (Part 1): Preliminary determination of controlled ingredients

目的:研制口腔科铸造纯钛冠桥专用包埋料。方法:选择A、B两种粘结剂、C砂、D粉。按照9.625∶1、7.500∶1、6.083∶1的粉液比,将C、D分别与两种粘结剂调和,包埋预先制作的片状(7mm×7mm×0.6mm)蜡熔模24片铸造。观察浆料的操作性能、型壳表面状态、铸件颜色等。筛选出较为理想的粘结剂,按1、3、5日测定其动力黏度、密度、PH值。结果:粘结剂A,浇注腔形成不规则的蜂窝状,有粉料堵塞浇注口,型壳外表面均有裂纹,无法完成铸件的浇注;粘结剂B粉液比7.500∶1组初凝时间合适,焙烧后型壳表面无裂纹,浇注腔壁完整光滑,铸件表面经喷砂呈明亮的金属色。粘结剂B 1、3、5日的黏度、密度、PH值无显著差别。结论:(1)粘结剂B与C砂、D粉按照粉液比7.500∶1混合后包埋蜡熔模、铸造,能够获得良好的铸件;(2)在实用环境下粘结剂B在5日内具有良好的性能指标。

Objective: Research on dental investment of titanium crown and bridge. Methods: Bond A and B togetherwith sand C and powder D were selected. C and D were mixed into A or B according to water/powder ratio 1∶9.625, 1∶7.500 and 1∶6.083. 24 wax sheet patterns (7mm×7mm×0.6mm) were invested. Then castings were fabricated.Manipulation performance, appearance of the casting mold and color of the castings were observed. Dynamic viscosity,consistency and pH value of bond B which was perfect were measured on different days (1, 3 or 5 days). Results:Alveolate structure was formed in molds for bond A. Some powder jammed the cast gate. There were cracks on the outersurface of the mold. And castings could not be produced. There were appropriate primary gel time, intact mold and castgate for group water/powder ratio 1∶7.500 of band B. And the surface of the castings showed bright metal color. Dynamicviscosity, consistency and pH value of different days for bond B had no significant difference. Conclution: (1) Favorablecastings could be fabricated for bond B when the water/powder ratio was 1∶7.500. (2) Bond B had steady capability in 5days in the practical condition.