Laboratory Bioengineering and Nanosciences, University of Montpellier, Montpellier, France.
Department of Prosthetic Dentistry, Faculty of Odontology, Montpellier University, France.
J Dent Res. 2023 Mar;102(3):295-301. doi: 10.1177/00220345221138500. Epub 2022 Dec 23.
The aim of this study is to visualize and characterize by ultra-high-speed imaging (UHSI) the failure phenomena at the resin-ceramic bonding interface of lithium disilicate (LiSi2) samples bonded with gold-standard protocol (Monobond Plus [MB]) and the nontoxic one (Monobond Etch & Prime [MEP]) subjected to mechanical loading. Unprecedented frame rate, image resolution, and recording time were reached by using the most advanced UHSI camera. The finite element analysis (FEA) of the proposed mechanical test confirmed that the specific design of our samples enables a combined shear and compression stress state, prone to test the bonding interface while being close to physiological stresses. Ten LiSi2 samples were pretreated by gold standard (MB, = 5) and self-etching primer (MEP, = 5). Axial compression loading gradually increased until catastrophic failure was performed. As shown by the FEA, the angle between the bonding interface and load direction leads to shear-compression stresses at the resin-ceramic bonding interface. Failure was recorded by UHSI at 300,000 fps. All recorded images were analyzed to segregate events and isolate the origin of fracture. For the first time, thanks to the image recording setup, it was observed that debonding is the first event before breakage, highlighting that sample fracture occurs by interfacial rupture followed by slippage and cohesive failure of materials. Failure mode could be described as mixed. MEP and MB showed similar results and behavior.
本研究旨在通过超高速成像（UHSI）可视化和表征锂硅（LiSi2）样本在树脂-陶瓷结合界面的失效现象，这些样本分别采用金标准方案（Monobond Plus [MB]）和非毒性方案（Monobond Etch & Prime [MEP]）进行结合，并承受机械载荷。通过使用最先进的 UHSI 相机，实现了前所未有的帧率、图像分辨率和记录时间。所提出的机械测试的有限元分析（FEA）证实，我们的样本的特定设计能够实现剪切和压缩复合应力状态，有利于在接近生理应力的情况下测试结合界面。10 个 LiSi2 样本分别经过金标准预处理（MB，n=5）和自酸蚀底漆预处理（MEP，n=5）。轴向压缩载荷逐渐增加，直至发生灾难性失效。如 FEA 所示，结合界面和载荷方向之间的角度导致树脂-陶瓷结合界面的剪切-压缩应力。通过 UHSI 以 300,000 fps 的帧率记录失效。对所有记录的图像进行分析，以分离事件并隔离断裂的起源。首次通过图像记录设置观察到，脱粘是断裂之前的第一个事件，这突出表明样本断裂是由界面破裂引起的，随后是材料的滑动和内聚失效。失效模式可以描述为混合模式。MEP 和 MB 表现出相似的结果和行为。
