Viscoelastic shear properties of porcine temporomandibular joint disc.
Viscoelastic shear properties of porcine temporomandibular joint disc.
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DOI：
10.1111/ocr.12088
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发表时间：
2015-04
影响因子：
3.1
通讯作者：
Yao H
中科院分区：
文献类型：
--
作者：
Wu Y;Kuo J;Wright GJ;Cisewski SE;Wei F;Kern MJ;Yao H
研究猪TMJ间盘的本征粘弹性剪切特性。选用6~8月龄幼猪新鲜TMJ骨盘12个。从TMJ盘的五个区域制备了厚度均匀(~1.2 mm)的圆柱形样品(直径5 mm)。在10%的压缩应变下进行扭转剪切试验。用两种方法进行了动态剪切试验：频率范围为0.01rad/10rad/S，恒定剪切应变幅度为0.025 rad；应变扫描测试范围为0.005-0.05rad，恒定频率为10rad/S，并进行了瞬时应力松弛试验，以确定平衡剪切特性。扫频试验中，随着扫频频率的增加，动态剪切复合模量值增大，取值范围为7~17kPa.相位角在11~15°范围内，没有随频率增加而呈现区域性变化的规律。动态剪切模数随剪应变的增大而减小。平衡剪切模量值在2~4.5kpa之间。后部的动态剪切模量值明显高于前部，而平衡剪切模量值的地区差异无统计学意义。我们的结果表明，在机械载荷作用下，TMJ圆盘的本征区域相关粘弹性剪切特性可能在决定TMJ圆盘的局部应变中起着关键作用。
To investigate the intrinsic viscoelastic shear properties in porcine TMJ discs. Twelve fresh porcine TMJ discs from young adult pigs (6-8 months) were used. Cylindrical samples (5 mm diameter) with uniform thickness (~1.2 mm) were prepared from five regions of the TMJ disc. Torsional shear tests were performed under 10% compressive strain. Dynamic shear was applied in two methods: a frequency sweep test over the frequency range of 0.01-10 rad/s with a constant shear strain amplitude of 0.025 rad, and a strain sweep test over the range of 0.005-0.05 rad at a constant frequency of 10 rad/s. Transient stress-relaxation tests were also performed to determine the equilibrium shear properties. As the frequency increased in the frequency sweep test, the dynamic shear complex modulus increased, with values ranging from 7 to 17 kPa. The phase angle, ranging from 11 to 15 degrees, displayed no pattern of regional variation as the frequency increased. The dynamic shear modulus decreased as the shear strain increased. The equilibrium shear modulus had values ranging from 2 to 4.5 kPa. The posterior region had significantly higher values for dynamic shear modulus than those in the anterior region while no significant regional difference was found for equilibrium shear modulus. Our results suggest that the intrinsic region-dependent viscoelastic shear characteristics of TMJ disc may play a crucial role in determining the local strain of the TMJ disc under mechanical loading.