Prager Martin, Pierce Mark, Atria Pablo J, Sampaio Camila, Cáceres Eduardo, Wolff Mark, Giannini Marcelo, Hirata Ronaldo
Department of Cariology and Comprehensive Care, New York University College of Dentistry.
Department of Biomedical Engineering Rutgers, The State University of New Jersey.
Dent Mater J. 2018 Jun 8;37(3):393-399. doi: 10.4012/dmj.2017-136. Epub 2018 Jan 26.
The understanding of cuspal deflection and volumetric shrinkage of resin composites is necessary to assess and improve the placement techniques of resin-based materials. The aim of this study was to investigate the cuspal deflection and its relationship with volumetric polymerization shrinkage of different bulk-fill resin composites. The investigation was conducted using non-contact phase microscopy and micro-computed tomography. Thirty custom-milled aluminum blocks were fabricated for microscopy analysis and thirty-six tooth models with standardized Class I cavities were used for micro-computed tomography analysis. Results showed that high-viscosity composites present higher cuspal deflection compared to bulk-fill composites. The filler loading of resin composites seems to have an effect on cusp deflection, since the higher the filler content percentage, the higher the cusp deflection. On the other hand, it seems to have an opposite effect on volumetric shrinkage, since higher filler loadings produced lower volumetric shrinkage percentages.
了解树脂复合材料的牙尖偏斜和体积收缩对于评估和改进树脂基材料的填充技术很有必要。本研究的目的是调查不同大块充填树脂复合材料的牙尖偏斜及其与体积聚合收缩的关系。该调查采用非接触相显微镜和显微计算机断层扫描进行。制作了30个定制研磨的铝块用于显微镜分析，并使用36个具有标准化I类洞的牙齿模型进行显微计算机断层扫描分析。结果表明，与大块充填复合材料相比，高粘度复合材料呈现出更高的牙尖偏斜。树脂复合材料的填料含量似乎对牙尖偏斜有影响，因为填料含量百分比越高，牙尖偏斜越高。另一方面，它似乎对体积收缩有相反的影响，因为较高的填料含量产生较低的体积收缩百分比。
