Department of Prosthodontics, Dental School, University of Southern Santa Catarina, Tubarão, SC, Brazil.
Braz Oral Res. 2010 Jul-Sep;24(3):336-41. doi: 10.1590/s1806-83242010000300013.
Dental impression is an important step in the preparation of prostheses since it provides the reproduction of anatomic and surface details of teeth and adjacent structures. The objective of this study was to evaluate the linear dimensional alterations in gypsum dies obtained with different elastomeric materials, using a resin coping impression technique with individual shells. A master cast made of stainless steel with fixed prosthesis characteristics with two prepared abutment teeth was used to obtain the impressions. References points (A, B, C, D, E and F) were recorded on the occlusal and buccal surfaces of abutments to register the distances. The impressions were obtained using the following materials: polyether, mercaptan-polysulfide, addition silicone, and condensation silicone. The transfer impressions were made with custom trays and an irreversible hydrocolloid material and were poured with type IV gypsum. The distances between identified points in gypsum dies were measured using an optical microscope and the results were statistically analyzed by ANOVA (p < 0.05) and Tukey's test. The mean of the distances were registered as follows: addition silicone (AB = 13.6 µm, CD=15.0 µm, EF = 14.6 µm, GH=15.2 µm), mercaptan-polysulfide (AB = 36.0 µm, CD = 36.0 µm, EF = 39.6 µm, GH = 40.6 µm), polyether (AB = 35.2 µm, CD = 35.6 µm, EF = 39.4 µm, GH = 41.4 µm) and condensation silicone (AB = 69.2 µm, CD = 71.0 µm, EF = 80.6 µm, GH = 81.2 µm). All of the measurements found in gypsum dies were compared to those of a master cast. The results demonstrated that the addition silicone provides the best stability of the compounds tested, followed by polyether, polysulfide and condensation silicone. No statistical differences were obtained between polyether and mercaptan-polysulfide materials.
印模是制作义齿的重要步骤，因为它提供了牙齿和相邻结构的解剖和表面细节的再现。本研究的目的是评估使用个体壳树脂覆盖印模技术获得的不同弹性体材料的石膏印模的线性尺寸变化。使用具有固定义齿特征的不锈钢制成的母模，带有两个预备基牙以获得印模。在基牙的咬合和颊面记录参考点（A、B、C、D、E 和 F）以记录距离。使用以下材料获得印模：聚醚、硫醇-聚硫、加成硅酮和缩合硅酮。使用定制托盘和不可逆转的水胶体材料获得转移印模，并使用 IV 型石膏进行浇铸。使用光学显微镜测量石膏模型中已识别点之间的距离，并通过方差分析（p < 0.05）和 Tukey 检验对结果进行统计学分析。记录的距离平均值如下：加成硅酮（AB = 13.6 µm，CD=15.0 µm，EF = 14.6 µm，GH=15.2 µm）、硫醇-聚硫（AB = 36.0 µm，CD = 36.0 µm，EF = 39.6 µm，GH = 40.6 µm）、聚醚（AB = 35.2 µm，CD = 35.6 µm，EF = 39.4 µm，GH = 41.4 µm）和缩合硅酮（AB = 69.2 µm，CD = 71.0 µm，EF = 80.6 µm，GH = 81.2 µm）。所有在石膏模型中发现的测量值均与母模进行了比较。结果表明，加成硅酮提供了测试化合物中最好的稳定性，其次是聚醚、聚硫和缩合硅酮。聚醚和硫醇-聚硫材料之间未获得统计学差异。
