Characterising the micro-mechanical behaviour of the carious dentine of primary teeth using nano-indentation
Characterising the micro-mechanical behaviour of the carious dentine of primary teeth using nano-indentation
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DOI：
10.1016/j.jbiomech.2004.07.012
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发表时间：
2005-07-01
影响因子：
2.4
通讯作者：
Kilpatrick, N
中科院分区：
文献类型：
--
作者：
Angker, L;Swain, MV;Kilpatrick, N
更好地认识龋齿本质的特性将在龋病评估和治疗中具有临床优势。本研究的目的是了解细菌脱矿过程对牙本质力学性能的影响以及扫描电子显微镜下观察到的牙本质结构的变化。8颗乳磨牙有未处理的龋性牙本质，对其进行轴位切片和精细抛光，以便进行纳米压痕。在每个标本上，使用纳米压痕(超微压痕系统，UMI-2000)从牙髓到病变腔底平行于小管方向，在病变组织中均匀分布六条压痕，另外两条压痕以相同的方式在相邻的牙本质健全区域上形成压痕。所有的测试都是在水合的样品上进行的。硬度和弹性模量值分别在0.56~0.001 GPa和14.55~0.015 Gpa范围内向空洞底板方向逐渐降低。力学性能的变化是作为病变深度的函数的特定模式，其中硬度可以符合指数函数，而整个病变的弹性模量的变化符合幂函数关系。对弹性模数数据的更严格的评估表明，两个截然不同的指数函数与结果非常吻合。这些弹性模数的变化也与整个病变的结构变化相匹配，这些结构变化与主要是肾小管周围溶解转变为肾小管间溶解有关。(C)2004爱思唯尔有限公司。保留所有权利。
A better appreciation of the properties of carious dentine would be of clinical advantage in carious assessment and management. The aim of this study is to understand the deterioration of the mechanical properties of carious dentine as a result of bacterial demineralising process as well as change in dentine structures observed under scanning electronic microscope. Eight primary molar teeth with untreated carious dentine were axially sectioned and fine polished for nano-indentation. On each specimen, six lines of indentation, evenly distributed through the lesion, were made from the pulp to lesion cavity floor parallel to tubule direction using nano-indentation (Ultra Micro Indentation System, UMIS-2000), while another two indentation lines were made on an adjacent region of sound dentine in the same manner. All tests were conducted on hydrated specimens. Hardness and elastic modulus decreased significantly and progressively toward the cavity floor varying from 0.56 to 0.001 GPa and 14.55 to 0.015 GPa, respectively. The change in mechanical properties was in a specific pattern as a function of lesion depth, in which the hardness could be fitted to an exponential function, while the variation of the elastic modulus across the entire lesion was fitted to a power law relationship. More critical evaluation of the elastic modulus data indicated that two distinct exponential functions provided an excellent fit to the results. These changes in elastic modulus also matched the structural changes seen across a lesion, which were associated with a change from primarily peritubular to intertubular dissolution. (c) 2004 Elsevier Ltd. All rights reserved.