Department of Conservative Dentistry and Dental Research Institute, Seoul National University, Yeongeon-Dong, Jongro-Ku, South Korea.
Dent Mater. 2010 May;26(5):443-8. doi: 10.1016/j.dental.2010.01.003. Epub 2010 Feb 18.
The aim of this study was to develop a method for measuring the slumping tendency of flowable resin composites and to correlate the results with those obtained from standard rheological methods.
Five commercial flowable composites (Aeliteflo: AF, Filtek flow: FF, DenFil flow: DF, Tetric flow: TF and Revolution: RV) were used. A fixed volume of each composite was extruded from a syringe onto a glass slide using a custom-made loading device. The composite was allowed to slump for 10s at 25 degrees C and light cured. The aspect ratio (height/diameter) of the cone or dome shaped specimen was measured to estimate the slumping tendency of the composites. In order to investigate the relationship between the slumping tendency and the rheological properties of the composites, the complex viscosity eta* of each composite was measured by a dynamic oscillatory shear test over a range of angular frequency omega=0.1-100rad/s using a rheometer. The aspect ratios of the composites were compared by one-way ANOVA and Tukey's post hoc test at the 5% significance level. Regression analysis was performed to investigate the relationship between the aspect ratio and the complex viscosity.
Slumping tendency based on the aspect ratio varied among the five materials (AF<FF<DF<TF<RV). Flowable composites exhibited pseudoplasticity in which the complex viscosity decreased with increasing frequency. Slumping resistance increased with increase in the complex modulus.
The slumping tendency could be quantified by measuring the aspect ratio of slumped flowable composites. This method may be applicable to evaluate the clinical handling characteristics of these materials.
本研究旨在开发一种测量可流动性树脂复合材料流变性的方法，并将结果与标准流变学方法的结果进行相关联。
使用五种商业可流动性复合材料（Aeliteflo：AF、Filtek flow：FF、DenFil flow：DF、Tetric flow：TF 和 Revolution：RV）。使用定制的加载装置，从注射器中挤出每种复合材料的固定体积，涂覆在载玻片上。在 25°C 下允许复合材料在 10 秒内塌缩并进行光固化。测量锥形或圆顶形试样的高宽比（高度/直径），以评估复合材料的塌缩趋势。为了研究塌缩趋势与复合材料流变性能之间的关系，使用流变仪在 0.1-100rad/s 的角速度范围内通过动态振荡剪切测试测量每种复合材料的复合粘度 eta*。使用单向方差分析和 Tukey 事后检验在 5%显著水平上比较复合材料的高宽比。进行回归分析以研究高宽比与复合粘度之间的关系。
基于高宽比的塌缩趋势在五种材料之间存在差异（AF<FF<DF<TF<RV）。可流动性复合材料表现出假塑性，即复合粘度随频率的增加而降低。塌缩阻力随复合模量的增加而增加。
通过测量塌缩可流动性复合材料的高宽比，可以定量评估塌缩趋势。这种方法可能适用于评估这些材料的临床操作特性。
