Effects of aging on the mechanical behavior of human dentin
Effects of aging on the mechanical behavior of human dentin
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DOI：
10.1016/j.biomaterials.2004.10.029
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发表时间：
2005-06-01
期刊：
影响因子：
14
通讯作者：
Reprogel, RK
中科院分区：
文献类型：
--
作者：
Arola, D;Reprogel, RK
对人牙本质的力学行为及年龄的影响进行了实验研究。从17至80岁的患者（N = 70）获得的未拔磨牙（N=76）的冠状牙本质上切下具有矩形横截面的梁。梁加载在准静态的4点弯曲或4点弯曲疲劳失效和刚度，强度和疲劳性能进行了评价。在表征疲劳响应时，梁被分为两个年龄组，这两个年龄组被认为是年轻的（17小于或等于年龄小于或等于30，平均值+/-标准差）。dev. = 25+/-5岁）和老年（50岁以下或等于80岁以下，平均值+/-标准差。dev. = 64+/-9岁）牙本质。单调加载的结果表明，牙本质的弯曲强度和断裂应变均随年龄的增长而显著降低。牙本质的疲劳寿命随循环应力幅的减小而增加，在所有循环应力幅下，年轻牙本质的疲劳强度均大于老年牙本质。年轻牙本质的疲劳强度（107次循环）约为44 MPa，而老年牙本质的疲劳强度约为23 MPa。基于年轻和年老样本的断裂表面的力学行为和微观特征的差异，老化似乎导致牙本质中损伤起始和传播的速率增加。(C)2004爱思唯尔有限公司保留所有权利。
An experimental study on the mechanical behavior of human dentin and the influence of age was conducted. Beams with rectangular cross-section were sectioned from the coronal dentin of virgin extracted molars (N=76) that were obtained from (N=70) patients between 17 and 80 years of age. The beams were loaded in either quasi-static 4-point flexure or 4-point flexural fatigue to failure and the stiffness, strength and fatigue properties were evaluated. In characterizing the fatigue response the beams were divided into two age groups that were regarded as young (17less than or equal toageless than or equal to30, mean+/-std. dev. = 25+/-5 years) and old (50less than or equal toageless than or equal to80, mean +/- std. dev. = 64+/-9 years) dentin. Results from monotonic loading showed that both the flexural strength and strain to fracture of dentin decreased significantly with age. The fatigue life of dentin increased with a reduction in cyclic stress amplitude and the fatigue strength of young dentin was greater than that of old dentin at all cyclic stress amplitudes. The endurance strength of young dentin (at 107 cycles) was approximately 44MPa, whereas the old dentin exhibited an endurance strength of approximately 23 MPa. Based on differences in the mechanical behavior and microscopic features of the fracture surfaces from the young and old specimens, aging appears to result in an increase in both the rate of damage initiation and propagation in dentin. (C) 2004 Elsevier Ltd. All rights reserved.