Dogan Sami, Schwedhelm E Ricardo, Heindl Harald, Mancl Lloyd, Raigrodski Ariel J
Assistant Professor, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash.
Clinical Associate Professor, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash.
J Prosthet Dent. 2015 Aug;114(2):217-22. doi: 10.1016/j.prosdent.2015.03.019. Epub 2015 May 12.
Impression making is a challenging clinical procedure for both patients and dentists.
The purpose of this clinical study was to compare a recently introduced fast-setting polyvinyl siloxane (PVS) impression material with heavy body/light body (HB/LB) combination (Imprint 4; 3M ESPE) (experimental group) with a conventional PVS impression material with HB/LB combination (Imprint 3; 3M ESPE) (control group), using the 1-step 2-viscosity impression technique.
Two definitive impressions (1 of each material combination) were made of 20 crown preparations from 20 participants. The quality of impressions was rated by 3 evaluators (clinical evaluator, clinical operator, and dental technician) and by the patients for the level of comfort and taste of the impression materials. The order in which the 2 impressions were made with each material combination was randomized for each crown preparation. A paired t test for paired means and McNemar test for paired proportions were used for statistical comparisons (α=.05).
Participants rated the comfort of the impression making with the experimental group significantly higher than that with the control group (P=.001). No significant differences were found in participants' rating for the taste of the impression materials (P=.46). The viscosity for tray material was rated as significantly better for the control group by the clinical operator (P=.004). The readability of the impression and visibility around the finish line were rated as significantly better for the experimental group than for the control group (P<.001). Except for the ease of removal of the stone (RS), the ratings for the 2 groups by the dental technician were similar. The ease of RS was rated as significantly better for the experimental group (P<.001). Eleven dies from the control and 9 from the experimental group were selected for fabrication of the definitive crowns (P=.65).
Within the limitations of this clinical study, no significant differences were found in the overall clinical performance of the experimental and the control groups. Impressions made with both materials were clinically acceptable. Participants rated the comfort provided by the experimental group significantly better than that of the control group.
制取印模对于患者和牙医来说都是一项具有挑战性的临床操作。
本临床研究的目的是使用一步法双粘度印模技术，将一种最近推出的快速凝固型聚乙烯基硅氧烷（PVS）印模材料与重体/轻体（HB/LB）组合（Imprint 4；3M ESPE）（实验组）与一种传统的PVS印模材料与HB/LB组合（Imprint 3；3M ESPE）（对照组）进行比较。
从20名参与者的20个牙冠预备体制取两种最终印模（每种材料组合各一个）。由3名评估者（临床评估者、临床操作者和牙科技师）以及患者对印模质量进行舒适度和印模材料味道方面的评分。对于每个牙冠预备体，每种材料组合制取两个印模的顺序是随机的。采用配对均值的配对t检验和配对比例的McNemar检验进行统计学比较（α = 0.05）。
参与者对实验组制取印模的舒适度评分显著高于对照组（P = 0.001）。在参与者对印模材料味道的评分方面未发现显著差异（P = 0.46）。临床操作者对对照组托盘材料的粘度评分显著更高（P = 0.004）。实验组印模的清晰度以及边缘线周围的可视性评分显著高于对照组（P < 0.001）。除了石膏脱模的难易程度（RS）外，牙科技师对两组的评分相似。实验组RS的难易程度评分显著更高（P < 0.001）。从对照组选取11个代型，从实验组选取9个代型用于制作最终牙冠（P = 0.65）。
在本临床研究的局限性范围内，实验组和对照组的总体临床性能未发现显著差异。两种材料制取的印模在临床上均可接受。参与者对实验组提供的舒适度评分显著高于对照组。
