Papadogianis Y, Boyer D B, Lakes R S
J Biomed Mater Res. 1985 Jan;19(1):85-95. doi: 10.1002/jbm.820190108.
The creep of microspecimens of posterior dental composites was studied using a torsional creep apparatus. Shear stresses were maintained for 3 h and recovery was followed for 50 h. Creep curves were obtained at 21, 37, and 50 degrees C and four torque levels. The effect of conditioning the specimens in water up to 8 weeks was studied. The posterior composites exhibited linear viscoelastic behavior at low deformations. They had higher shear moduli and greater resistance to creep than conventional and microfilled composites. In aging experiments, maximum shear moduli occurred when specimens were 48 h to 1 week old. Subsequent softening was attributed to water absorption. Residual strain was highest when the composites were stressed within 24 h of initiating polymerization. Residual strain was very low in specimens 48 h to 8 weeks of age.
使用扭转蠕变仪研究了后牙复合材料微观样本的蠕变情况。剪切应力保持3小时，并跟踪50小时的恢复情况。在21、37和50摄氏度以及四个扭矩水平下获得了蠕变曲线。研究了将样本在水中处理长达8周的效果。后牙复合材料在低变形时表现出线性粘弹性行为。它们比传统复合材料和微填料复合材料具有更高的剪切模量和更强的抗蠕变能力。在老化实验中，样本在48小时至1周龄时出现最大剪切模量。随后的软化归因于吸水。当复合材料在引发聚合反应后24小时内受力时，残余应变最高。在48小时至8周龄的样本中，残余应变非常低。
