Papadoyannis J, Helvatzoglou-Antoniadis M, Sapountzis M, Kalinderis E
Odontostomatol Proodos. 1989 Dec;43(6):513-20.
The creep and recovery of microspecimens of glass-ionomer cements was studied using a tortional creep apparatus. The purpose was to investigate viscoelastic behavior in a low stress that might result from normal chewing forces. Small stress (2,048 MPa), below the composite resin's proportional limit, was maintained for 3 h and after the stress was released. Recovery was followed for 50 h. The measurements were made on specimens: aged 24 h stored dry at 21 degrees C, aged 24 h stored in distilled water at 21 degrees C, aged 24 h stored in distilled water at 37 degrees C, aged 1 week stored in distilled water at 37 degrees C. The glass-ionomer cements exhibited linear viscoelastic behavior at low deformations. The materials did not recover their original shape after 50 h after the stress was removed. The least amount of creep and permanent deformation exhibited the specimens aged for 1 week in distilled water at 37 degrees C. The influence of dehydration was apparent on specimens measured dry at 21 degrees C. They exhibited the greatest amount of creep and permanent deformation.
使用扭转蠕变仪研究了玻璃离子水门汀微试样的蠕变和恢复情况。目的是研究在正常咀嚼力可能产生的低应力下的粘弹性行为。在低于复合树脂比例极限的小应力（2048兆帕）下保持3小时，然后释放应力。跟踪恢复情况50小时。对以下试样进行了测量：在21℃干燥储存24小时、在21℃蒸馏水中储存24小时、在37℃蒸馏水中储存24小时、在37℃蒸馏水中储存1周。玻璃离子水门汀在低变形时表现出线性粘弹性行为。应力去除50小时后，材料未恢复其原始形状。在37℃蒸馏水中老化1周的试样表现出的蠕变和永久变形量最少。脱水对在21℃干燥测量的试样的影响很明显。它们表现出最大量的蠕变和永久变形。
