Hutton J E, Marshall G W
University of California, School of Dentistry, Department of Restorative Dentistry, San Francisco, USA.
J Prosthet Dent. 1995 Feb;73(2):126-31. doi: 10.1016/s0022-3913(05)80150-7.
This study investigated the thermal expansion of phosphate-bonded investment materials. Three investments were mixed with either distilled water or their special liquids and allowed a setting time of 1 or 24 hours. Hydration and thermal expansions were measured with a vertical dilatometer and were analyzed for interactive and main effects. The amount of expansion attributed to hydration was minimal, whereas thermal expansions varied and were of greater magnitudes. Material I exhibited the greatest thermal expansion. Materials II and III recorded smaller thermal expansions that increased when the materials were mixed with their special liquids. Setting time did not substantially influence hydration expansions but did influence thermal expansions, and heating the materials to 800 degrees C instead of 700 degrees C did not dramatically elevate expansions.
本研究调查了磷酸盐结合包埋材料的热膨胀情况。将三种包埋材料分别与蒸馏水或其专用液体混合，并设定凝固时间为1小时或24小时。使用垂直膨胀仪测量水化和热膨胀，并对交互作用和主效应进行分析。水化引起的膨胀量极小，而热膨胀则有所不同且幅度更大。材料I表现出最大的热膨胀。材料II和III记录的热膨胀较小，当与专用液体混合时热膨胀会增加。凝固时间对水化膨胀影响不大，但对热膨胀有影响，将材料加热到800℃而非700℃并不会显著提高膨胀率。
