Bacchi Atais, Feitosa Victor Pinheiro, da Silva Fonseca Andrea Soares Quirino, Cavalcante Larissa Maria Assad, Silikas Nikolaos, Schneider Luis Felipe Jochins
Department of Prosthetic Dentistry, School of Dentistry, Meridional Faculty - IMED, Passo Fundo, RS, Brazil.
Department of Restorative Dentistry, School of Dentistry, Federal University of Ceará, Fortaleza, Ceará, Brazil.
J Conserv Dent. 2015 Sep-Oct;18(5):384-8. doi: 10.4103/0972-0707.164051.
to evaluate the shrinkage, polymerization stress, elastic and bulk modulus resulting from composites formulated by siloranes, 2(nd) generation ormocers, and dimethacrylates.
The bonded disc method was used to evaluate volumetric shrinkage. The polymerization stress was evaluated by mean of the Bioman. Cylindrical specimens (5 mm thickness and 6 mm diameter) were submitted to gradual loading. Young's and bulk modulus were obtained from the slope of the stress/strain curve. Data were analyzed using one-way analysis of variance and Tukey's test (5%).
Grandio and ormocer showed significant higher elastic and bulk modulus. Silorane presented significant lowest bulk modulus and maximum shrinkage. Ormocer and silorane presented lower values for the maximum rate of shrinkage. Extra-low shrinkage (ELS) composite presented the greatest maximum shrinkage. The higher maximum rate of shrinkage was attained by Grandio and ELS, statistically similar from each other. The silorane showed lower values of maximum stress and maximum rate of stress. The higher values of maximum stress were presented by ELS and Grandio, statistical similar between them. Grandio showed the significantly greatest maximum rate of stress.
Silorane showed to promote lower shrinkage/stress among the composites, with the lowest elastic modulus. Ormocer showed lower shrinkage/stress than methacrylates despite of its high modulus.
评估由硅氧烷、第二代有机金属陶瓷和二甲基丙烯酸酯配制的复合材料的收缩率、聚合应力、弹性模量和体积模量。
采用粘结圆盘法评估体积收缩率。通过Bioman评估聚合应力。将圆柱形试件（厚度5mm，直径6mm）进行逐步加载。从应力/应变曲线的斜率获得杨氏模量和体积模量。使用单向方差分析和Tukey检验（5%）分析数据。
Grandio和有机金属陶瓷显示出显著更高的弹性模量和体积模量。硅氧烷的体积模量显著最低，收缩率最大。有机金属陶瓷和硅氧烷的最大收缩率较低。超低收缩（ELS）复合材料的最大收缩率最大。Grandio和ELS的最大收缩率较高，两者在统计学上相似。硅氧烷的最大应力和最大应力率较低。ELS和Grandio的最大应力值较高，两者在统计学上相似。Grandio的最大应力率显著最大。
硅氧烷在复合材料中表现出较低的收缩率/应力，弹性模量最低。有机金属陶瓷尽管模量较高，但收缩率/应力比甲基丙烯酸酯低。
