Photomechanical characterization of dentin hard tissue mechanics

牙本质硬组织是一种复杂的、水合的生物复合材料，形成牙齿的主要部分。尽管已知牙本质的无机和有机部分与机械性能的相关性，但牙本质对机械力的响应的微观结构变化和材料性能梯度的影响尚未得到很好的确定。了解功能适应的微观结构和材料性能梯度对重要结构生物材料（如牙本质）的机械完整性的作用一直是一个具有挑战性的问题;然而，过去的研究没有共同努力调查组织各向异性对牙科硬组织功能反应的影响。缺乏对牙齿硬组织功能特征的理解是牙齿断裂和牙齿修复/假体/种植体遇到的其他许多问题的主要原因。光力学实验是高分辨率的全场实验，提供实时原位信息，在生理负荷。目前的研究计划将集中在发展光力学实验，以确定牙本质硬组织的微观应变，研究成分变化和微观结构变化对牙本质对机械载荷的响应的作用。采用光力学实验、有限元分析和体外牙本质模型实验。所提出的基于微应变/应力的牙本质组织对力的响应的理解不仅将为生物材料的开发提供良好的力学基础，而且还有助于开发模型来预测牙本质在不同模拟条件下的生物力学响应。该项目将在硬组织表征和硬组织康复方面开辟新的前景。

Dentin hard-tissue is a complex, hydrated, biocomposite that forms the major bulk of teeth. Though the relevance of the inorganic and organic fractions of dentin on the mechanical properties is known, the effect of microstructural variations and material property gradients on the response of dentin to mechanical forces is not well established. Understanding the role of functionally adapted microstructural and material property gradients on the mechanical integrity of an important structural biomaterial such as dentin has always been a challenging problem; however, past research have made no concerted effort to investigate the effect of tissue-anisotropy on the functional response of dental hard-tissues. This dearth in the understanding of the functional characteristics of dental hard-tissue is the primary reason for tooth fracture and other numerous problems encountered with restorations/prostheses/implants. Photomechanical experiments are high resolution whole-field experiments that provide real-time in situ information, under physiological loads. The current research program will focus on developing photomechanical experiments to determine the microstrains of dentin hard tissue, study the role of compositional changes and microstructural changes on the response of dentin to mechanical loads. Photomechanical experiments, Finite Element Analysis and in vitro experiments on dentin models will be employed. The proposed microstrain/stress based understanding of the dentin tissue response to forces will not only provide a sound mechanistic basis for biomaterial development, but also aid in developing models to predict biomechanical response of dentin at different simulated conditions. This project will open new vistas in hard-tissue characterization and rehabilitation of hard-tissues.