Nakabayashi N, Watanabe A, Arao T
Institute for Medical and Dental Engineering, Tokyo Medical and Dental University, Japan.
J Dent. 1998 May;26(4):379-85. doi: 10.1016/s0300-5712(97)00021-3.
To determine the efficacy of a miniaturized dumbbell test procedure designed to more easily identify defect(s) in bonded dentine test specimens.
Extracted human dentine substrates were pre-conditioned with 10-3 solution for 10, 30 or 60 s prior to dentine bonding with 4-META/MMA-TBB resin. Miniaturized dumbbell-shaped test specimens were prepared from the resin bonded samples. After 24 h storage in 37 degrees C water, the specimens were tensile-loaded to failure. Fractured surfaces and cross-sections were examined and compared under scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
Cohesive failure within the bonding resin was observed in specimens pre-conditioned for 10 s. The tensile bond strength of these was excellent. Bond strengths of specimens that were pre-conditioned for 30 and 60 s were significantly lower, and defects in these specimens, formerly difficult or impossible to identify, were readily identified under SEM and TEM microscopy.
The proposed method of tensile stressing to failure and microscopically examining fractured miniaturized dumbbell-shaped test specimens is a simple and reproducible test procedure. The protocol is capable of clearly elucidating defective resin infiltration of demineralized dentine in bonded interfaces. These defects are difficult to visualize by conventional and/or ISO recommended methods.
确定一种小型哑铃测试程序的有效性，该程序旨在更轻松地识别粘结牙本质测试样本中的缺陷。
在使用4-META/MMA-TBB树脂粘结牙本质之前，将提取的人牙本质基质用10⁻³溶液预处理10、30或60秒。从树脂粘结样本中制备小型哑铃形测试样本。在37℃水中储存24小时后，对样本进行拉伸加载直至破坏。在扫描电子显微镜（SEM）和透射电子显微镜（TEM）下检查并比较断裂表面和横截面。
在预处理10秒的样本中观察到粘结树脂内的内聚破坏。这些样本的拉伸粘结强度极佳。预处理30秒和60秒的样本的粘结强度明显较低，并且这些样本中以前难以或无法识别的缺陷在SEM和TEM显微镜下很容易识别。
所提出的拉伸至破坏并通过显微镜检查断裂的小型哑铃形测试样本的方法是一种简单且可重复的测试程序。该方案能够清晰地阐明粘结界面中脱矿牙本质的树脂浸润缺陷。这些缺陷通过传统方法和/或ISO推荐方法很难观察到。
