Cooney J P, Doyle T M, Caputo A A
J Prosthet Dent. 1979 Apr;41(4):411-7. doi: 10.1016/0022-3913(79)90038-6.
Two phosphate-bonded investments and one calcium sulfate investment were evaluated for the surface smoothness and marginal fit they impart to gold castings. A modified technique was also evaluated for each phosphate-bonded investment, where the silica sol was not diluted and the spatulation time was reduced. The results of this study lead to the following conclusions: 1. The marginal fits obtained with all four phosphate-bonded methods were comparable to each other and superior to that obtained with the calcium sulfate investment. 2. The presence of nodules on the surface of the castings was more prevalent with the phosphate-bonded investments. However, this effect was not statistically significant. 3. Clinical assessment of the roughness of the castings revealed that all the methods tested produced clinically acceptable castings. 4. Visual observation by five dentists revealed that both the recommended and modified techniques for one of the phosphate-bonded investments (Ceramigold) produced a smoother surface than any other investment tested. Rating of scanning electron microscope photographs (X600) revealed no difference in the surface roughness between any of the castings. Consequently, no definitive relation between investment type or technique and surface roughness was established. 5. No correlation was demonstrated between surface roughness, as evaluated by either clinical observation or scanning electron microscope photography, and marginal fit of the castings.
对两种磷酸盐粘结包埋材料和一种硫酸钙包埋材料进行了评估，以考察它们赋予金铸件的表面光洁度和边缘适合性。还对每种磷酸盐粘结包埋材料评估了一种改良技术，即不稀释硅溶胶并缩短搅拌时间。本研究结果得出以下结论：1. 所有四种磷酸盐粘结方法获得的边缘适合性相互可比，且优于硫酸钙包埋材料获得的边缘适合性。2. 磷酸盐粘结包埋材料铸造的铸件表面出现结节的情况更为普遍。然而，这种影响在统计学上并不显著。3. 对铸件粗糙度的临床评估表明，所有测试方法生产的铸件在临床上均可接受。4. 五名牙医的视觉观察表明，一种磷酸盐粘结包埋材料（Ceramigold）的推荐技术和改良技术所生产的铸件表面比其他任何测试包埋材料都更光滑。扫描电子显微镜照片（X600）评级显示，任何铸件之间的表面粗糙度均无差异。因此，未确定包埋材料类型或技术与表面粗糙度之间的明确关系。5. 通过临床观察或扫描电子显微镜摄影评估的表面粗糙度与铸件的边缘适合性之间未显示出相关性。
