藻酸盐印模的不同保存状态对尺寸稳定性的影响

Effect of various conditions on size stability of alginate impression

目的探讨藻酸盐印模在非密封或密封状态下放置不同时间对尺寸稳定性的影响。方法实验分为藻酸盐印模非密封10min组4、0min组和80min组,藻酸盐印模密封10min组、40min组和80min组,另设1组空白对照。分别用普通石膏、硬石膏和超硬石膏制取模型,电子数显卡尺测量标准实物及石膏模型尺寸,进行ANOVA比较(α=0.05)。结果在藻酸盐印模非密封10min、40min和80min三组中,普通石膏、硬石膏和超硬石膏所灌注的模型尺寸表现为逐渐增加的趋势;在藻酸盐印模密封10min4、0min和80min三组中,三种石膏模型尺寸变化表现为先减小后增大的趋势。各组间存在显著性差异(P<0.05)。结论随放置时间的延长,藻酸盐印模在非密封和密封不同状态下,可发生不同的印模尺寸变化。

Objective To observe the size stability of alginate impression under sealed and non - sealed condi- tions. Methods A blank group and six experimental groups included： 10min sealed group, 10rain non - sealed group, 40rain sealed group, 40min non - sealed group, 80rain sealed group and 80rain non - sealed group. Impressions were poured by using common gypsum, anhydrite gypsum and ultrahard gypsum, respectively. The measured data were used to carry out ANOVA （ α = 0.05）. Results Size of sealed groups took on expansive tendency, but non - sealed groups took on decreasing tendency firstly and expansive tendency followed （ P 〈 0.05 ）. Conclusions Alginate impression took on different size stability under sealed and non - sealed conditions because of permeation and syneresis mechanism.