Department of Endodontics, Faculty of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
Aust Dent J. 2012 Sep;57(3):349-54. doi: 10.1111/j.1834-7819.2012.01703.x. Epub 2012 Jun 14.
Resin-based cements are brittle materials and the major shortcomings of these materials are manifested in their sensitivity to flaws and defects. Although various mechanical properties of resin luting cements have been described, few fracture toughness test data for resin-based luting cements using the short rod design have been published.
Specimens were prepared from five resin luting cements. For each material a total of 36 disc-shaped specimens were prepared using a custom-made mould. Specimens were randomly divided into six groups of six, immersed in two solutions: distilled water and 0.01 mol/L lactic acid at 37 °C for 24 hours, 1 month or 3 months. The specimens were loaded using a universal testing machine. The maximum load at specimen failure was recorded and the K(Ic) (MPa. M 0.5) was calculated.
There was a relationship between material, storage solution and time (p < 0.05). Nexus 3 showed the highest K(Ic) followed by Panavia F, Calibra, Smart Cem2 and seT.
The fracture toughness of the resin luting cements was affected by both time and storage solution. Comparable fracture toughness of conventional resin cement and self-adhesive resin cements was observed.
树脂基粘结剂是一种脆性材料，这些材料的主要缺点表现为对缺陷和瑕疵敏感。尽管已经描述了各种树脂粘结剂的机械性能，但使用短棒设计的树脂基粘结剂的断裂韧性测试数据却很少见。
从五种树脂粘结剂中制备试件。对于每种材料，使用定制模具总共制备了 36 个圆盘形试件。试件随机分为六组，每组六个，分别浸泡在两种溶液中：蒸馏水和 0.01mol/L 乳酸，在 37°C 下分别浸泡 24 小时、1 个月和 3 个月。使用万能试验机对试件进行加载。记录试件失效时的最大载荷，并计算 K(Ic)(MPa·m 0.5)。
材料、储存溶液和时间之间存在关系(p<0.05)。Nexus 3 的 K(Ic)最高，其次是 Panavia F、Calibra、Smart Cem2 和 seT。
树脂粘结剂的断裂韧性受到时间和储存溶液的影响。观察到传统树脂粘结剂和自粘结树脂粘结剂具有可比的断裂韧性。
