抄録
Purpose: This investigation examined the influence of water absorption on creep compliance and fluidity of acrylic tissue conditioners.
Methods: Six commercially available acrylic tissue conditioners were used in this investigation. All materials were mixed for 20 sec according to the mixing proportion recommended by the manufacturer and allowed to set at room temperature (23±0.5 °C). Each specimen was stored immediately after preparation in an air cabinet or in a water bath maintained at either 23±0.5 °C or 37±0.5 °C. Two measurements were taken using an electronic balance to determinate water absorption and using a creep testing instrument under constant load to examine creep behavior.
Results: The specimen weight in all materials containing ethyl alcohol decreased markedly from the start of immersion in water. In the case of ethyl alcohol-free material, the specimen weight increased immediately after immersion in water. The relative creep compliances (J(2)95/23, J(60)95/23, and J(120)95/23) and the relative fluidity (φ95/23) decreased linearly with increases in the amount of water absorption.
Conclusion: With an increase in the amount of water absorption, each material showed increased resistance to deformation and accelerated the deterioration of its flow property.
