论文部分内容阅读
随着齿科铸造技术的不断提高,铸造包埋料的研究也取得不少进展,现将有关问题综述如下。一、带模铸造模型材料强度的增强耐火模型材料的强度,除磷酸盐包埋料外,其它类型材料的强度多数是不够的,以石膏作为结合剂来提高强度,通常含量只占包埋料的25%,如超过40～50%,其热膨胀率就会显著下降,且使铸件表面粗糙。不用提高石膏的比例,而用松香溶液浸泡,或用松香溶液和硅溶胶液调拌石膏系包埋料,也能提高模型强度。此法尤其适用于嵌体、全冠、卡环等小型铸件的铸造。二、方石英的应用包埋料中如用二氧化硅的同素异构体方石英,提高包埋料的膨胀值较为理想。普通石英包埋料的膨胀值仅为0.5～1.0%,方石
With the continuous improvement of dental casting technology, research on casting embedded material has also made a lot of progress. The relevant issues are summarized as follows. First, die casting mold material strength enhancement Fire-resistant model material strength, in addition to phosphate-coated material, the strength of other types of material is not enough to gypsum as a binder to improve the strength, usually only accounted for the amount of embedded material Of 25%, such as more than 40 to 50%, the thermal expansion rate will be significantly reduced, and castings rough surface. Without increasing the proportion of gypsum, and soaked with rosin solution, or rosin solution and silica sol blending plaster embedding material, but also can improve the model strength. This method is especially suitable for casting inlays, crowns, snap rings and other small castings. Second, the application of Fang Shiyang Embedding material such as silica allotrope cristobalite, embedding material to improve the expansion value is more ideal. Ordinary quartz embedding material expansion value of only 0.5 to 1.0%, calamite