Biomaterials Science Research Group, School of Dentistry, University of Manchester, United Kingdom; College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
Biomaterials Science Research Group, School of Dentistry, University of Manchester, United Kingdom.
Dent Mater. 2016 Aug;32(8):998-1006. doi: 10.1016/j.dental.2016.05.006. Epub 2016 May 28.
To investigate a set of resin-composites and the effect of their composition on polymerization shrinkage strain and strain kinetics, shrinkage stress and the apparent elastic modulus.
Eighteen commercially available resin-composites were investigated. Three specimens (n=3) were made per material and light-cured with an LED unit (1200mW/cm(2)) for 20s. The bonded-disk method was used to measure the shrinkage strain and Bioman shrinkage stress instrument was used to measure shrinkage stress. The shrinkage strain kinetics at 23°C was monitored for 60min. Maximum strain and stress was evaluated at 60min. The shrinkage strain rate was calculated using numerical differentiation.
The shrinkage strain values ranged from 1.83 (0.09) % for Tetric Evoceram (TEC) to 4.68 (0.04) % for Beautifil flow plus (BFP). The shrinkage strain rate ranged from 0.11 (0.01%s(-1)) for Gaenial posterior (GA-P) to 0.59 (0.07) %s(-1) for BFP. Shrinkage stress values ranged from 3.94 (0.40)MPa for TET to 10.45 (0.41)MPa for BFP. The apparent elastic modulus ranged from 153.56 (18.7)MPa for Ever X posterior (EVX) to 277.34 (25.5) MPa for Grandio SO heavy flow (GSO).
The nature of the monomer system determines the amount of the bulk contraction that occurs during polymerization and the resultant stress. Higher values of shrinkage strain and stress were demonstrated by the investigated flowable materials. The bulk-fill materials showed comparable result when compared to the traditional resin-composites.
研究一组树脂复合材料及其组成对聚合收缩应变和应变动力学、收缩应力和表观弹性模量的影响。
研究了 18 种市售的树脂复合材料。每种材料制作 3 个试件（n=3），并用 LED 装置（1200mW/cm²）光固化 20s。采用粘结盘法测量收缩应变，用 Bioman 收缩应力仪测量收缩应力。在 23°C 下监测收缩应变动力学 60min。在 60min 时评估最大应变和应力。使用数值微分法计算收缩应变率。
收缩应变值范围从 Tetric Evoceram（TEC）的 1.83（0.09）%到 Beautifil flow plus（BFP）的 4.68（0.04）%。收缩应变率范围从 Gaenial posterior（GA-P）的 0.11（0.01%s-1）到 BFP 的 0.59（0.07）%s-1。收缩应力值范围从 TET 的 3.94（0.40）MPa 到 BFP 的 10.45（0.41）MPa。表观弹性模量范围从 Ever X posterior（EVX）的 153.56（18.7）MPa 到 Grandio SO heavy flow（GSO）的 277.34（25.5）MPa。
单体系统的性质决定了聚合过程中发生的总体收缩量和产生的应力。所研究的流动性材料表现出更高的收缩应变和应力值。与传统的树脂复合材料相比，块状填充材料表现出相当的结果。
