Sykora O, Sutow E J
Department of Dental Clinical Sciences, Dalhousie University, Faculty of Dentistry, Halifax, N. S., Canada.
J Prosthet Dent. 1997 Feb;77(2):205-8. doi: 10.1016/s0022-3913(97)70236-1.
Although relatively well-fitting dentures are produced at low cost and with easy-to-manipulate material, current denture base materials are not ideal. Because acrylic resin complete and removable partial dentures change dimensionally as a result of polymerization and thermal contractions, a high expansion stone was tested in this study to determine its ability to compensate for some of the dimensional change.
Maxillary complete dentures were processed on type III dental stone and high expansion stone casts. The accuracy of fit along the posterior palatal border was measured and compared after the prostheses were trimmed and polished and after their immersion in water at 23 degrees C at 1-day and 1-week intervals.
Statistical analysis of the data revealed that at every measurement interval the maxillary complete dentures processed on high expansion stone had posterior palatal border openings that were significantly smaller when compared with type III dental stone (p < 0.001).
尽管使用低成本且易于操作的材料能制作出相对贴合的假牙，但目前的义齿基托材料并不理想。由于丙烯酸树脂全口义齿和可摘局部义齿会因聚合反应和热收缩而发生尺寸变化，本研究对一种高膨胀石膏进行了测试，以确定其补偿部分尺寸变化的能力。
在上颌全口义齿的Ⅲ型石膏模型和高膨胀石膏模型上制作义齿。在义齿修整、抛光后，以及在23摄氏度的水中浸泡1天和1周后，测量并比较沿后腭缘的贴合精度。
数据的统计分析显示，在每个测量间隔，与Ⅲ型石膏相比，在高膨胀石膏上制作的上颌全口义齿后腭缘开口明显更小（p < 0.001）。
