Marghalani Hanadi Y, Watts David C
DRBBA-Research Group, Operative Dentistry Division, Conservative Dental Science Department (CDS), Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.
Dent Mater. 2013 Sep;29(9):963-70. doi: 10.1016/j.dental.2013.07.009. Epub 2013 Jul 31.
To study time-dependent viscoelastic deformation (creep and recovery) of resin-composites, after conditioning in food-simulating solvents, under a compressive stress at 37°C.
Five dimethacrylate-based composites: (Spectrum TPH, Premise Body, Tetric Ceram HB, Filtek P60, X-tra fil), and two Ormocers (Experimental Ormocer V 28407, Admira) were studied. Three groups of cylindrical specimens (4mm×6mm) were prepared and then conditioned in 3 solvents: methyl ethyl ketone (MEK), ethanol, and water for 1 month at 37°C. The compressive creep-strain under 35MPa in 37°C water was recorded continuously for 2h and then the unloaded recovery-strain was monitored for another 2h. The data were analyzed by one-way ANOVA and Bonferroni's test.
The materials all exhibited classic creep and recovery curves, with most parameters being significantly different (p<0.0001) for each solvent condition. All materials showed lower creep-strain in water than in ethanol or MEK solvents. Maximum creep-strain and permanent-set gave negative linear-regression (r(2)>0.98) with logarithm of the solvent solubility-parameter. The % mean (SD) creep-strain ranged from a minimum of 0.82 (0.01) for the Exp. Ormocer in water to the maximum of 4.19 (0.30) for Admira in MEK. Similar trends were found for permanent-set. The dimethacrylate-based composites behaved as an intermediate group, apart from X-tra fil that had similar stability to the Exp. Ormocer.
The viscoelastic stability (low creep and permanent-set) of the Exp. Ormocer, compared to many dimethacrylate-based composites, in food-simulating solvents may be due to its diluent-free formulation. This was closely matched by a highly-filled dimethacrylate material (X-tra fil).
研究在37°C压缩应力下，树脂复合材料在食品模拟溶剂中处理后的时间依赖性粘弹性变形（蠕变和恢复）。
研究了五种基于二甲基丙烯酸酯的复合材料（Spectrum TPH、Premise Body、Tetric Ceram HB、Filtek P60、X-tra fil）和两种有机硅氧烷聚合物（实验性有机硅氧烷聚合物V 28407、Admira）。制备三组圆柱形试样（4mm×6mm），然后在37°C下于三种溶剂（甲基乙基酮（MEK）、乙醇和水）中处理1个月。连续记录在37°C水中35MPa下的压缩蠕变应变2小时，然后再监测2小时的卸载恢复应变。数据采用单因素方差分析和Bonferroni检验进行分析。
所有材料均呈现出典型的蠕变和恢复曲线，每种溶剂条件下的大多数参数均存在显著差异（p<0.0001）。所有材料在水中的蠕变应变均低于在乙醇或MEK溶剂中的蠕变应变。最大蠕变应变和永久变形与溶剂溶解度参数的对数呈负线性回归（r(2)>0.98）。平均（标准差）蠕变应变百分比范围从水中实验性有机硅氧烷聚合物的最小值0.82（0.01）到MEK中Admira的最大值4.19（0.30）。永久变形也发现了类似趋势。除X-tra fil与实验性有机硅氧烷聚合物具有相似稳定性外，基于二甲基丙烯酸酯的复合材料表现为中间组。
与许多基于二甲基丙烯酸酯的复合材料相比，实验性有机硅氧烷聚合物在食品模拟溶剂中的粘弹性稳定性（低蠕变和永久变形）可能归因于其无稀释剂配方。一种高填充二甲基丙烯酸酯材料（X-tra fil）与之密切匹配。
