摘要
目的:观察水粉比对超硬石膏制取全牙列模型精度和表面硬度的影响。方法:制取一个标准下颌牙列金属母模。用两种水粉比(22∶100;25∶100)调拌超硬石膏材料,制取20个模型,每组10个。用测量显微镜测量模型各标志点的距离,用布洛维硬度机测量模型表面硬度,所得数据进行统计分析。结果:①不同水粉比制备超硬石膏模型,模型各线段长度变化无明显统计学意义(P>0.05);②当超硬石膏的水粉比增大为25g∶100g时,模型的表面硬度出现显著的变化(P<0.01),从数值可看出为硬度的降低。结论:①适当增加水粉比,模型仍可获得较高的精度。②随着水粉比的增加,模型表面硬度和抗磨损性降低。
Objective: To study the effect of water/powder ratio on accuracy and hardness of die stone models. Methods: A metal lower jaw dental cast was used as a master model. Twenty die stone models were made with the water/powder ratios at 22:100 and 25:100 respectively, I0 models in each group, The dimensions between landmarks were measured under microscope and the hardness was measured by hardness sclerometer. Results: ①Change of water/powder ratio of die stone from 22g: 100g to 25: 100g didn' t affect the accuracy of models(P〉0.05);② When water/powder ratios of die stone rose to 25:100,the hardness of model decreased significantly(P〈0.01). Conclusions: ③ Water/powder ratio of die stone had no significant effect on its dimensional accuracy, ④Surface hardness and abrasion resistance of models decreased greatly when the W/P ratio of die stone changed from 22g: 100g to 25: 100g.
出处
《口腔颌面修复学杂志》
2005年第4期290-292,共3页
Chinese Journal of Prosthodontics
关键词
牙科
模型材料
超硬石膏
水粉比
dental
modeling material
die stone
water/powder ratio