Walker Mary P, Petrie Cynthia S, Haj-Ali Reem, Spencer Paulette, Dumas Chris, Williams Karen
Department of Restorative Dentistry, University of Missouri-Kansas City School of Dentistry, MO 64108, USA.
J Prosthodont. 2005 Sep;14(3):158-63. doi: 10.1111/j.1532-849X.2005.04024.x.
This investigation evaluated and compared the dimensional accuracy and surface detail reproduction of two hydrophilic polyvinylsiloxane (PVS) and two polyether (PE) impression materials when used under dry and moist conditions.
Impressions were made of stainless steel dies as described in ANSI/ADA specification no. 19, with two vertical and three horizontal lines inscribed on the die superior surface. Impressions were made under dry and moist conditions (17 impressions per condition for each material). Dimensional accuracy was measured by comparing the average length of the middle horizontal line in each impression with the same line on the metal die using a measuring microscope with an accuracy of 0.001 mm. Surface detail reproduction was evaluated by using criteria similar to ADA specification no. 19: continuous replication of at least two of the three horizontal lines.
The mean percent dimensional change and SD values ranged from -0.135% (0.035) to 0.053% (0.031). A two-way analysis of variance (ANOVA) indicated that moisture did not cause significant adverse effects on the dimensional accuracy of any material (p > 0.05); however, significant differences were found between the materials (p < .05). The surface detail evaluation indicated that moisture had a significant effect on detail reproduction of PVS materials (Pearson's Chi square, p < 0.05). Under dry conditions, all materials produced satisfactory detail reproduction 100% of the time; however, under moist conditions, only 29% of Aquasil and Genie Ultra PVS impressions produced satisfactory detail reproduction, while 100% of Permadyne Garant and Impregum Penta Soft PE impressions still met the surface detail criteria.
Although moisture may not adversely affect the dimensional accuracy of either PE or hydrophilic PVS material, the evidence suggests that PE material is more likely to produce impressions with superior detail reproduction in the presence of moisture.
本研究评估并比较了两种亲水性聚乙烯基硅氧烷（PVS）印模材料和两种聚醚（PE）印模材料在干燥和潮湿条件下使用时的尺寸精度和表面细节再现性。
按照美国国家标准学会/美国牙科协会（ANSI/ADA）第19号规范制作不锈钢模具的印模，在模具上表面刻有两条垂直线和三条水平线。在干燥和潮湿条件下制作印模（每种材料每种条件下制作17个印模）。使用精度为0.001 mm的测量显微镜，通过比较每个印模中水平中线的平均长度与金属模具上同一条线的长度来测量尺寸精度。使用与ADA第19号规范类似的标准评估表面细节再现性：三条水平线中至少两条的连续复制。
平均尺寸变化百分比和标准差范围为-0.135%（0.035）至0.053%（0.031）。双向方差分析（ANOVA）表明，湿度对任何材料的尺寸精度均未产生显著不利影响（p>0.05）；然而，材料之间存在显著差异（p<0.05）。表面细节评估表明，湿度对PVS材料的细节再现具有显著影响（Pearson卡方检验，p<0.05）。在干燥条件下，所有材料在100%的时间内都能产生令人满意的细节再现；然而，在潮湿条件下，只有29%的Aquasil和Genie Ultra PVS印模产生了令人满意的细节再现，而100%的Permadyne Garant和Impregum Penta Soft PE印模仍符合表面细节标准。
尽管湿度可能不会对PE或亲水性PVS材料的尺寸精度产生不利影响，但有证据表明，在有湿度的情况下，PE材料更有可能产生具有优异细节再现性的印模。
