Zhang Zihou, Mutluay Mustafa, Tezvergil-Mutluay Arzu, Tay Franklin R, Pashley David H, Arola Dwayne
Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD, USA.
Adhesive Dentistry Research Group, Department of Cariology, Institute of Dentistry, University of Turku, Turku, Finland.
Dent Mater. 2017 Aug;33(8):904-914. doi: 10.1016/j.dental.2017.04.006. Epub 2017 May 31.
Application of collagen cross-linkers to demineralized dentin improves bond durability. While the benefits of cross-linking treatments to bond strength and fatigue resistance have been explored, changes in hybrid layer stiffness with aging have not been examined.
To examine the influence of a cross-linking treatment using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) on hybrid layer stiffness of resin-dentin adhesive bonds, using spatially-resolved nanoscopic Dynamic Mechanical Analysis (nanoDMA).
Bonded interface specimens were prepared using a two-step (SB) or three-step (SBMP) etch-and-rinse adhesive. Adhesive bonding of the treated groups was preceded by a 1min application of an experimental EDC conditioner to the acid-etched dentin. Control specimens did not receive EDC treatment. The bonded interfaces were evaluated using nanoDMA to determine the dynamic mechanical properties after storage in artificial saliva at 37°C for 0, 3 and 6 months.
The EDC treatment had no influence on the dynamic mechanical properties of the hybrid layer immediately after bonding. There was also no reduction in the hybrid layer stiffness after 3 and 6 months aging as defined by the complex modulus and storage modulus. However, there was a significant reduction in the loss modulus and tanδ components (i.e. viscous behavior) of the hybrid layers with aging. Degradation occurred to both adhesive systems with storage, but was greatest for SB. Without EDC treatment, the reduction in tanδ of the hybrid layer prepared with SB exceeded 80% in 6 months.
The application of EDC to acid-etched dentin helps maintain the viscoelasticity of hybrid layers.
将胶原蛋白交联剂应用于脱矿牙本质可提高粘结耐久性。虽然已经探讨了交联处理对粘结强度和抗疲劳性的益处，但尚未研究混合层刚度随老化的变化。
使用空间分辨纳米动态力学分析（nanoDMA）研究1-乙基-3-（3-二甲基氨基丙基）碳二亚胺（EDC）交联处理对树脂-牙本质粘结剂混合层刚度的影响。
使用两步法（SB）或三步法（SBMP）蚀刻冲洗粘结剂制备粘结界面标本。在处理组进行粘结之前，先对酸蚀牙本质应用1分钟的实验性EDC调节剂。对照标本未接受EDC处理。使用nanoDMA评估粘结界面，以确定在37°C人工唾液中储存0、3和6个月后的动态力学性能。
EDC处理对粘结后立即混合层的动态力学性能没有影响。在3个月和6个月老化后，由复数模量和储能模量定义的混合层刚度也没有降低。然而，随着老化，混合层的损耗模量和tanδ分量（即粘性行为）显著降低。两种粘结系统都会随着储存而降解，但SB降解最严重。未经EDC处理，用SB制备的混合层tanδ在6个月内降低超过80%。
将EDC应用于酸蚀牙本质有助于维持混合层的粘弹性。
