熔模类型及放置时间对冠熔模精度影响的研究

Precision of Wax Pattern Crown with Different Materials at Different Time

目的:研究3种不同熔模材料的蜡型及放置时间对冠熔模精密性的影响。方法:用同一标准模具翻制30个石膏代型,随机分为3组,每组10个,分别用日本松风公司、德国BEGO公司和国产的嵌体蜡在石膏代型上采用滴蜡法各制作10个熔模,于蜡型完成0、10、20、30、60、120、240min后,用投影测量仪测量蜡型边缘的浮出量,比较其边缘的密合性。结果:3种材料的冠蜡型在前20min的边缘浮出量与20min后的边缘浮出量有高度差异性(P<0.01),30min的边缘浮出量与60、120、240min的浮出量无差异性(P>0.05);在各个时间点,松风蜡及BEGO蜡的边缘浮出量和国产蜡的边缘浮出量有高度差异性(P<0.01),在0、10和20min,松风蜡与BEGO蜡间有差异性(P<0.05)。结论:不同种类的熔模材对冠蜡型的精度影响不同,在本试验中,松风蜡冠熔模的密合性较好;熔模完成后在0min时精度最高,30min后对精度的影响较小。

Objective：To evaluate the influence of different pattern materials on the marginal precision of wax pattern at different time.Methods：Standard specimens simulating post tooth crown were made.3 groups of wax patterns were completed on the standard specimens with three kinds of pattern wax.There were 10 wax crowns in every group.The marginal opening of the wax pattern was measured under projector-measure-meter at the time of 0,10,20,30,60,120,240 minutes.The data were statistically analyzed using one-way ANOVA at a significance level of 0.05.Results：There was significant difference among 0,10,20,30 minutes and other time in every groups（P〈0.01）.There was no significant difference between 30 minutes and the remains（P〉0.05）.And there was significant difference between the first two groups and the last group in every periods（P〈0.01）.Some difference was also found between the first group and the second group at 0,10,20 minutes.Conclusion：Within the limitation of this study,precision of pattern crown was affected by the type of wax used and the time.