Microtensile bond strength testing and failure analysis of two dentin adhesives
Microtensile bond strength testing and failure analysis of two dentin adhesives
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DOI：
10.1016/s0109-5641(98)00008-6
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发表时间：
1998-01-01
期刊：
影响因子：
5
通讯作者：
Keller, JC
中科院分区：
文献类型：
--
作者：
Armstrong, SR;Boyer, DB;Keller, JC
目标.这项调查进行，以确定两种牙科粘合剂的拉伸粘结强度，使用最近推出的“微拉伸”粘结强度测试设计，并验证每个测试样本的失效模式与扫描电子显微镜（SEM）。将提取的人磨牙安装在石头上，并垂直于牙齿的长轴从咬合面去除釉质。根据制造商的说明，使用每种牙科粘合剂系统在平坦的牙本质表面形成复合树脂冠。24小时后，垂直于粘合剂接头对粘合试样进行切片，每个牙齿产生6至7个薄板。将这些牙本质/粘合剂/复合树脂板从石块上切下，并安装到定制的树脂玻璃固定装置中进行修剪，随后在粘合后7 d进行拉伸粘合强度测试。两种粘接剂的粘接强度比较采用t检验。用扫描电镜检查断裂试样，以确定断裂位置或失效模式。每种粘合剂系统的失效被分类为界面（联合或混合）或基底（牙本质和复合材料），并通过Fisher精确检验进行评估。All-Bond 2（Bisco）和Optibond FL（Kerr）的拉伸粘合强度和失效模式无显著差异。60%（12/20）的断裂涉及所有粘合剂2，发生在界面处，7例完全保持在关节内，而Optibond FL有35%（7/20）涉及界面的相同部分，2例完全在关节内。牙本质或复合材料的内聚性断裂占总失效模式的55%（21/ 40）。剩余牙本质厚度对所测的抗张强度无显著影响。这种多功能的新方法允许从单个牙齿或修复体内的小表面积进行多次测量，但需要仔细解释失效模式，以防止对测试实用性得出不适当的结论。(C)1998年牙科材料学院。出版社：Elsevier Science Ltd
Objectives. This investigation was conducted to determine the tensile bond strength of two dental adhesives using a recently introduced "microtensile" bond strength testing design and to verify the failure mode for each test specimen with scanning electron microscopy (SEM).Methods. Extracted human molars were mounted in stone and the enamel was removed from the occlusal surface perpendicular to the long axis of the tooth. A composite resin crown was formed an this fiat dentin surface utilizing each dental adhesive system according to manufacturer's instructions. Twenty-four hours later the bonded test specimens were sectioned perpendicular to the adhesive joint, producing six to seven thin slabs per tooth. These dentin/adhesive/composite resin slabs were sectioned free from the stone block and mounted into custom Plexiglas fixtures for trimming and subsequent tensile bond strength testing at 7 d post-bonding. The bond strength of the two adhesives was statistically compared with the t test. The broken specimens were examined with SEM to determine the fracture location or failure mode. Failures for each adhesive system were categorized as either interfacial (joint or mixed) or substrate (dentin and composite) and evaluated by Fisher's exact test.Results. The tensile bond strength and failure modes of All-Bond 2 (Bisco) and Optibond FL (Kerr) were not significantly different. Sixty per cent (12/20) of fractures involving All Bond 2 occurred at the interface, with seven being entirely maintained within the joint, whereas Optibond FL had 35% (7/20) involving same portion of the interface, two totally within the joint. Cohesive fractures of either dentin or composite accounted for 55% of the total failure modes (21/ 40). The remaining dentin thickness did not affect the measured tensile bond strength.Significance. This versatile new method permits multiple measurements from a single tooth or small surface areas within a restoration but careful interpretation of the failure mode is required to prevent inappropriate conclusions about the utility of the test. (C) 1998 Academy of Dental Materials. Published by Elsevier Science Ltd.