Farzin Mitra, Derafshi Reza, Giti Rashin, Kalantari Mohammad-Hassan
Department of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
Biomaterials Research Center, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
J Int Soc Prev Community Dent. 2020 Mar 5;10(2):196-204. doi: 10.4103/jispcd.JISPCD_469_19. eCollection 2020 Mar-Apr.
Dimensional accuracy of impressions is crucial to the quality of fixed restorations. This accuracy can be highly affected by the type of core and impression materials. This study aimed to assess the effect of different core materials on dimensional accuracy of two silicone impression materials.
In this study, three master core models were fabricated of amalgam, composite resin, and nickel-chromium. Of each model, 30 impressions were taken; 15 with additional and 15 with condensational silicone impression material. The accuracy of impressions of the three core materials was assessed by measuring two linear dimensions and one vertical dimension on the stone casts.
Data were analyzed with two-way analysis of variance and Scheffe test (α = 0.05).
Accuracy of the three measured dimensions was significantly affected by both the impression and core materials ( < 0.05). Additional silicone was significantly more accurate in linear dimensions, and impressions of the amalgam core were significantly more accurate than other cores in linear dimensions.
Additional silicone impression material had more detail reproduction, and the impressions of amalgam core were more accurate than the composite and nickel-chromium core materials.
印模的尺寸精度对固定修复体的质量至关重要。这种精度会受到核材料和印模材料类型的高度影响。本研究旨在评估不同核材料对两种硅橡胶印模材料尺寸精度的影响。
在本研究中，用汞合金、复合树脂和镍铬合金制作了三个主核模型。每个模型取30个印模；15个用加成型硅橡胶印模材料，15个用缩合型硅橡胶印模材料。通过测量石膏模型上的两个线性尺寸和一个垂直尺寸来评估三种核材料印模的精度。
数据采用双向方差分析和谢费检验（α = 0.05）进行分析。
三种测量尺寸的精度均受到印模材料和核材料的显著影响（P < 0.05）。加成型硅橡胶在线性尺寸上显著更精确，汞合金核的印模在线性尺寸上比其他核的印模显著更精确。
加成型硅橡胶印模材料具有更好的细节再现性，汞合金核的印模比复合树脂和镍铬合金核材料的印模更精确。
