Takahashi J, Okazaki M, Kimura H, Haeuchi Y, Kubo F
Department of Dental Technology, Osaka University Faculty of Dentistry, Japan.
J Dent Res. 1988 Oct;67(10):1278-83. doi: 10.1177/00220345880670100701.
Twenty experimental phosphate-bonded investments were prepared by the mixing of two types of fillers (spherical glass beads and irregularly shaped silica particles) with five types of filler aggregates of different porosities, and two different ratios of MgO to NH4H2PO4. These investments were mixed with three different liquids, and their setting expansion, time until setting expansion began (induction time), and fluidity were measured under constant experimental conditions. The following results were obtained: (1) The setting expansion was significantly related to bulk porosity of filler aggregates, not to packed porosity, despite variations in type of filler, ratio of MgO to NH4H2PO4 or type of liquid; and (2) the fluidity and the time until setting expansion began were also related to the bulk porosity of the filler aggregates.
通过将两种类型的填料（球形玻璃珠和不规则形状的二氧化硅颗粒）与五种不同孔隙率的填料聚集体以及两种不同比例的氧化镁与磷酸二氢铵混合，制备了20种实验性磷酸盐粘结包埋材料。将这些包埋材料与三种不同的液体混合，并在恒定的实验条件下测量它们的凝固膨胀、开始凝固膨胀的时间（诱导时间）和流动性。得到以下结果：（1）尽管填料类型、氧化镁与磷酸二氢铵的比例或液体类型存在差异，但凝固膨胀与填料聚集体的总体孔隙率显著相关，与堆积孔隙率无关；（2）流动性和开始凝固膨胀的时间也与填料聚集体的总体孔隙率有关。
