Asakura Masaki, Hayashi Tatsuhide, Tsuruta Shozo, Yamamoto Mitsunori, Kobayashi Shuichiro, Mieki Akimichi, Kawai Tatsushi
Department of Dental Materials Science, School of Dentistry, Aichi Gakuin University.
Department of Endodontics, School of Dentistry, Aichi Gakuin University.
Dent Mater J. 2017 Nov 29;36(6):700-705. doi: 10.4012/dmj.2016-164. Epub 2017 Jun 15.
The purpose of this study is to develop a method for quantifying the fluidity of flowable resin composites using determinations of yield stress. Five commercially available composites (AliteFlo LV, Flow-it ALC, Venus flow, Tetric N-flow, Revolution Formula2) were investigated. Yield stress values were obtained by plotting shear stresses for a range of shear rates, followed by fitting of Casson fluid models to flow curve data and extrapolation to the stress axis. To confirm that yield stress reflected fluidity, apparent viscosity at the lower shear rate (0.2 s) was calculated from flow curves. Yield stresses ranged from 5.4 to 43.1 Pa, and were found to capture differences in the fluidity of composites that were not captured by viscosity measurement at the low shear rate. Yield stress is directly proportional to fluidity, and could serve as a simple and precise indicator for selecting flowable resin composites for use in various clinical applications.
本研究的目的是开发一种通过测定屈服应力来量化可流动树脂复合材料流动性的方法。对五种市售复合材料（AliteFlo LV、Flow-it ALC、Venus flow、Tetric N-flow、Revolution Formula2）进行了研究。通过绘制一系列剪切速率下的剪应力，然后将卡森流体模型拟合到流动曲线数据并外推到应力轴来获得屈服应力值。为了确认屈服应力反映了流动性，根据流动曲线计算了较低剪切速率（0.2 s）下的表观粘度。屈服应力范围为5.4至43.1 Pa，发现其能够捕捉到低剪切速率下粘度测量未捕捉到的复合材料流动性差异。屈服应力与流动性成正比，可作为选择用于各种临床应用的可流动树脂复合材料的简单而精确的指标。
