IXdent: Integrative X-ray techniques for chemical and structural characterizations of dental interzones

牙科治疗包括用人工不可降解材料修复退化的牙齿组织，目的是获得持久的机械和美学耐用性。在健康的牙齿组织和牙齿修复之间不可避免地会形成一层厚厚的界面(区间)。我们将充填和牙齿组织之间的过渡区确定为一个不同的区域，我们此后将其命名为牙间带，其中的成分不同于充填物和组成充填物的牙齿组织。因此，牙间带包括各种牙科材料和牙釉质或牙本质等自然硬组织的分级结构之间的复杂微几何和化学梯度。在牙科研究中，对材料成分的不稳定性、老化、变化以及对充填和牙齿基质之间的间隙的影响进行的方法学研究有限。追踪并列材料中的动态降解是具有挑战性的，因为它们在主要成分(天然牙齿组织中以轻元素为主，而填充材料中典型的是重元素)、密度和结构上不同。该项目的目的是通过将同步X射线折射射线照相术(SXRR)和体层摄影术(SXRCT)以及微X射线CT成像(µXCT)和微X射线荧光(µXRF)相结合，提出一种适用于牙间带的多模式定量成像方法。为此，所使用的方法将根据调查对象进行调整，3D数据集将被耦合(注册)，包括不确定性评估在内的定量考虑将使该方法成为真正的分析工具。这一进展将为绘制牙齿修复失败图铺平道路，并有助于了解牙齿组织和人工充填材料之间及其周围的可预测变化。这是朝着控制有害的化学和结构/密度降解迈出的重要一步，并可能成为牙科研究的一种新的标准方法工具。未来的最终目标是支持和加强临床治疗程序。

Dental treatment includes restoration of degraded tooth tissue with artificial non-degradable materials with the aim of achieving long-lasting mechanical and aesthetic durability. Inevitably a thick interface (interzone) is formed between healthy tooth tissue and dental restoration. We identify the transition region between filling and tooth tissue as a distinct region that we henceforth name 'dental interzone', where composition is different from both the filling and dental tissue that comprise the filling. Thus, dental interzones comprise complex micro-geometries and chemical gradients, between a variety of dental materials and the hierarchical structure of natural hard tissues such as enamel or dentin. Degradation in such interzones is often the reason for restoration failure and a need for retreatment.In dental research there have been limited methodological studies on material composition instability, ageing and changes and effects on the immediate vicinity of interzones between filling and tooth substrate. Tracking of dynamic degradation in the juxtaposed materials is challenging, as they differ in main constituents (light elements prevail in the natural tooth tissue, whereas heavy elements are typical for fillings), density and structure. The aim of this project is to advance a multi-modal quantitative imaging methodology adapted to dental interzones by coupling synchrotron X-ray refraction radiography (SXRR) and tomography (SXRCT) as well as micro X-ray CT imaging (µXCT) with micro-X-ray fluorescence (µXRF) in 2 and 3 dimensions. For this purpose, the used methods will be adapted to the objects of investigation, the 3D data sets will be coupled (registered) and quantitative considerations including uncertainty evaluations will render the methodology into a true analytical tool.This development will pave the way to mapping tooth restoration failure and help understand predictable changes close to and around the interzones between dental tissue and artificial filling material. This is an important step towards controlling unwanted chemical and structural/density degradation and might become a new standard methodological instrument in dental research. The ultimate goal in the future is to support and enhance clinical treatment procedures.