Montoya Carolina, Arola Dwayne, Ossa Edgar Alexander
School of Engineering, Universidad Eafit, Medellín, Colombia.
Department of Materials Science & Engineering, University of Washington, Seattle, WA, USA.
Gerodontology. 2018 Jun;35(2):95-100. doi: 10.1111/ger.12321. Epub 2018 Jan 25.
This study aimed to identify the changes in the time-dependent deformation response of coronal dentin with ageing and its relationship with changes in chemical composition.
The structural behaviour of dentin with ageing is affected by changes in the density and diameter of its dentinal tubules (ie porosity), as well as changes in chemical composition throughout the tooth. However, little is known about the time-dependent deformation behaviour of aged dentin and the importance of its hierarchical structure and variations in chemical composition.
The spherical indentation response of aged coronal dentin was analysed in the outer, middle and inner regions, and its time-dependent deformation response was modelled in terms of its microstructure and chemical composition using a model recently proposed for young dentin.
The viscous deformation behaviour of aged dentin followed a power-law response with a decrease in the stress exponent when compared to young dentin. These results can be explained by cross-linking of the collagen present in the tissue.
A decrease in the deformation ability of aged dentin was found. This behaviour could be a result of a dissolution process and reprecipitation of the minerals present in intertubular dentin into the dentinal tubules.
本研究旨在确定冠部牙本质随年龄增长的时间依赖性变形响应变化及其与化学成分变化的关系。
牙本质随年龄增长的结构行为受其牙本质小管的密度和直径变化（即孔隙率）以及整个牙齿化学成分变化的影响。然而，关于老化牙本质的时间依赖性变形行为及其层次结构和化学成分变化的重要性知之甚少。
分析了老化冠部牙本质在外部、中部和内部区域的球形压痕响应，并使用最近为年轻牙本质提出的模型，根据其微观结构和化学成分对其时间依赖性变形响应进行建模。
与年轻牙本质相比，老化牙本质的粘性变形行为遵循幂律响应，应力指数降低。这些结果可以通过组织中存在的胶原蛋白交联来解释。
发现老化牙本质的变形能力降低。这种行为可能是管间牙本质中存在的矿物质溶解并重新沉淀到牙本质小管中的结果。
