Dentin Bonding Testing Using a Mini-interfacial Fracture Toughness Approach
Dentin Bonding Testing Using a Mini-interfacial Fracture Toughness Approach
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DOI：
10.1177/0022034515618960
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发表时间：
2016-03-01
影响因子：
7.6
通讯作者：
Van Meerbeek, B.
中科院分区：
文献类型：
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作者：
Pongprueksa, P.;De Munck, J.;Van Meerbeek, B.
与传统的粘合强度测试相比，界面断裂韧性（iFT）的测量被认为是评估粘合有效性的更有效的方法。然而，常见的断裂韧性测试非常费力，并且需要相对较大的样本尺寸。本研究旨在评估一种新的简化和小型化 iFT（mini-iFT）测试。将代表主要粘合剂类别的四种牙本质粘合剂和 1 种玻璃离子水门汀应用于平坦的牙本质上。 Mini-iFT（1.5 x 2.0 x 16 至 18 毫米）和微拉伸粘合强度（μ TBS；1.5 x 1.5 x 16 至 18 毫米）样本由同一颗牙齿制备。对于mini-iFT标本，在水冷下用150μm金刚石刀片在粘合剂-牙本质界面处切出单个凹口；样品在 4 点弯曲测试装置中加载直至失效。有限元分析用于分析 mini-iFT 测试期间的应力分布。检查了平均 mini-iFT 和 mu TBS 之间的相关性，发现具有显着性；发现了很强的正相关性（r(2) = 0.94，P = 0.004）。 Weibull 数据分析表明 mini-iFT 的变化小于 mu TBS。 mini-iFT 和 mu TBS 都显示出相同的性能顺序，其中 3 步蚀刻和冲洗粘合剂的性能优于 2 步自蚀刻和 2 步蚀刻和冲洗粘合剂，其次是 1 步 SE 粘合剂，最后是玻璃离聚物粘固剂。扫描电子显微镜失效分析显示，在微型 iFT 测试中，粘合剂-牙本质界面在实际界面处失效更多，而 mu TBS 样本在牙本质和复合材料中失效更多。有限元分析证实了这一发现，显示在微型 iFT 加载和裂纹扩展期间应力集中在界面处。总之，新的 mini-iFT 测试在评估粘合有效性方面比 mu TBS 更具辨别力和有效性；尽管如此，后一种测试仍然更加通用。样本大小和工作量相似，使得 mini-iFT 测试成为流行的 mu TBS 测试的有效替代方案。
Measurement of interfacial fracture toughness (iFT) is considered a more valid method to assess bonding effectiveness as compared with conventional bond strength testing. Common fracture toughness tests are, however, laborious and require a relatively bulky specimen size. This study aimed to evaluate a new simplified and miniaturized iFT (mini-iFT) test. Four dentin adhesives, representing the main adhesive classes, and 1 glass ionomer cement were applied onto flat dentin. Mini-iFT (1.5 x 2.0 x 16 to 18 mm) and microtensile bond strength (mu TBS; 1.5 x 1.5 x 16 to 18 mm) specimens were prepared from the same tooth. For the mini-iFT specimens, a single notch was cut at the adhesive-dentin interface with a 150-mu m diamond blade under water cooling; the specimens were loaded until failure in a 4-point bending test setup. Finite element analysis was used to analyze stress distribution during mini-iFT testing. The correlation between the mean mini-iFT and mu TBS was examined and found to be significant; a strong positive correlation was found (r(2) = 0.94, P = 0.004). Weibull data analysis suggested the mini-iFT to vary less than the mu TBS. Both the mini-iFT and the mu TBS revealed the same performance order, with the 3-step etch-and-rinse adhesive outperforming the 2-step self-etch and 2-step etch-and-rinse adhesive, followed by the 1-step SE adhesive and, finally, the glass ionomer cement. Scanning electron microscopy failure analysis revealed the adhesive-dentin interface to fail more at the actual interface with the mini-iFT test, while mu TBS specimens failed more within dentin and composite. This finding was corroborated by finite element analysis showing stress to concentrate at the interface during mini-iFT loading and crack propagation. In conclusion, the new mini-iFT test appeared more discriminative and valid than the mu TBS to assess bonding effectiveness; the latter test nevertheless remains more versatile. Specimen size and workload were alike, making the mini-iFT test a valid alternative for the popular mu TBS test.