Oskui Iman Z, Hashemi Ata
Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran.
Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran.
J Biomech. 2016 Mar 21;49(5):756-764. doi: 10.1016/j.jbiomech.2016.02.020. Epub 2016 Feb 13.
As a support to the tooth, the mechanical response of the periodontal ligament (PDL) is complex. Like other connective tissues, the PDL exhibits non-linear and time-dependent behavior. The viscoelasticity of the PDL plays a significant role in low and high loading rates. Little information, however, is available on the short-term viscoelastic behavior of the PDL. Also, due to the highly non-linear stress-strain response, it was hypothesized that the dynamic viscoelastic properties of the PDL would be greatly dependent on the preload. Therefore, the present study was designed to explore the dynamic tensile properties of the bovine PDL as a function of loading frequency and preload. The in vitro dynamic tensile tests were performed over a wide range of frequencies (0.01-100Hz) with dynamic force amplitude of 1N and different preloads of 3, 5 and 10N. The generalized Maxwell model was utilized to describe the non-linear viscoelastic behavior of the PDL. The low loss factor of the bovine PDL, measured between 0.04 and 0.08, indicates low energy dissipation due to the high content of collagen fibers. Moreover, the influence of viscous components in the linear region of the stress-strain curve (10N preload) was lower than those of the toe region (3N preload). The data reported in this study could be used in developing accurate computational models of the PDL.
作为牙齿的一种支撑结构，牙周韧带（PDL）的力学响应较为复杂。与其他结缔组织一样，PDL表现出非线性和时间依赖性行为。PDL的粘弹性在低加载速率和高加载速率下都起着重要作用。然而，关于PDL短期粘弹性行为的信息却很少。此外，由于其高度非线性的应力-应变响应，有人推测PDL的动态粘弹性特性将极大地依赖于预负荷。因此，本研究旨在探讨牛PDL的动态拉伸特性与加载频率和预负荷的关系。体外动态拉伸试验在0.01 - 100Hz的宽频率范围内进行，动态力幅值为1N，预负荷分别为3N、5N和10N。采用广义麦克斯韦模型来描述PDL的非线性粘弹性行为。牛PDL的损耗因子较低，在0.04至0.08之间，这表明由于胶原纤维含量高，能量耗散较低。此外，在应力-应变曲线的线性区域（10N预负荷）中粘性成分的影响低于趾部区域（3N预负荷）。本研究报告的数据可用于开发精确的PDL计算模型。
