Montoya C, Arola D, Ossa E A
School of Engineering, Universidad Eafit, Medellín, Colombia.
Department of Materials Science & Engineering, University of Washington, Seattle, WA, USA; Departments of Restorative Dentistry and Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA, USA.
Arch Oral Biol. 2017 Apr;76:20-29. doi: 10.1016/j.archoralbio.2017.01.003. Epub 2017 Jan 4.
The viscoelastic behavior of dentin and its ability to undergo time dependent deformation are considered to be important to oral functions and its capacity to resist fracture. There are spatial variations in the microstructure of dentin within the crown, which could be important to the viscous behavior. However, a spatially resolved description for the viscoelastic behavior of coronal dentin has not been reported.
In this investigation spherical indentations were made in three regions of coronal dentin including the outer, middle and inner regions. Power law relations were developed to quantitatively describe the stress-strain responses of the tissue.
Results showed that the deformation behavior was strongly dependent on the composition (mineral to collagen ratio) and microstructure (tubule density), which contributed to an increase in the rate of viscous deformation with increasing proximity to the pulp.
A model accounting for spatial variations in composition and microstructure was developed to describe the steady-state time dependent deformation behavior of coronal dentin, and a good agreement was found with the experimental results.
牙本质的粘弹性行为及其随时间产生变形的能力被认为对口腔功能及其抗断裂能力很重要。牙冠内牙本质的微观结构存在空间差异，这可能对粘性行为很重要。然而，尚未有关于牙冠部牙本质粘弹性行为的空间分辨描述的报道。
在本研究中，在牙冠部牙本质的三个区域（包括外层、中层和内层区域）进行了球形压痕试验。建立了幂律关系以定量描述该组织的应力-应变响应。
结果表明，变形行为强烈依赖于组成（矿物质与胶原蛋白的比例）和微观结构（小管密度），随着靠近牙髓，粘性变形速率增加。
建立了一个考虑组成和微观结构空间变化的模型来描述牙冠部牙本质的稳态时间依赖性变形行为，并且该模型与实验结果吻合良好。
