Material aging abutting restorations: predicting dentine sclerosis

在InterDent研究小组的范围内，项目1检查了化学老化的牙本质的微/纳米结构和化学属性，这是一种自然生物材料，经常变得硬化，特别是在牙齿填充物附近。为了预测牙本质硬化过程中牙本质结构和成分的动态变化，有必要对牙本质硬化过程中的这些化学和材料性质的变化进行定量的评估。尽管当代牙科粘合剂的临床性能普遍有所改善，但较小的侵入性治疗需要了解作为基质的先前处理过的化学老化牙本质的状态。我们假设牙本质与修复体的结合经历了微妙的微观结构和性质的变化，并随着时间的推移而积累。我们使用含锌的牙齿填充材料来探索这种化学老化过程的时空方面。随着逐渐的化学老化，小管内部和周围的成分发生变化，无论是在成分方面还是与小管上的距离都有一定的关系。在该项目中，通过三个研究所之间的合作，我们使用材料科学的方法来量化修复体附近牙本质密度和矿物属性的变化。高灵敏度的3DXRF方法将与衍射和成像研究相结合，以探索化学成分和机械变形能力的变化。利用高分辨率2D和3D方法，将这种天然材料转变为具有机械能力以维持修复牙齿的功能的过渡带的各个方面正在进行量化。我们将阐明关键元素的分布和化学状态的变化，如钙-牙本质的正常成分-和锌-一种主要通过扩散过程引入结构的元素。我们的总体目标是开发一种牙本质硬化症模型系统，以高灵敏度和高分辨率非破坏性地量化变化，并将不同分析技术获得的结果相互关联。我们期望获得更好的材料和对结构和元素组成变化的临床理解，我们将在模型系统和体内发育的硬化组织之间进行比较。

Within the scope of the research group InterDent, project 1 examines micro/nano structural and chemical attributes of chemically-aged dentine, a natural biomaterial that often becomes sclerotic especially near dental fillings. To predict the dynamics of structural and compositional changes incurred in treated dentine, it is necessary to assess these chemical and material property changes during the process of dentine sclerosis in a quantitative manner. Despite a general improvement in clinical performance of contemporary dental adhesives, less invasive treatment requires knowledge about the state of previously treated, chemically aged dentine that serves as a substrate. We hypothesize that dentine abutting restorations undergoes subtle microstructure and property changes, accumulating with time. We use Zn-containing dental filling materials to explore spatio-temporal aspects of this chemical aging process. With increased gradual chemical aging, the composition within and around tubules changes with some relation to the filling both in terms of composition and with relation to distance along tubules. Within the project and through cooperation between 3 institutes, we use material science methods to quantify changes in the density and mineral attributes of dentine near restorations. High sensitivity 3D XRF methods will be combined with diffraction and imaging investigations to explore changes in chemical composition and mechanical deformability. Various aspects of the transformation of this natural material into a transition 'interzone' that still has mechanical competence to sustain function within restored teeth are being quantified using high resolution 2D and 3D methods. We will elucidate changes in the distribution and chemical state of crucial elements such as Ca - normal constituent of dentine - and Zn - an element primarily introduced into the structure through diffusion processes. Our overall objectives are to develop a dentinal sclerosis model system, to quantify the changes non-destructively with high sensitivity and with high resolution and to correlate results obtained by different analytical techniques. We anticipate obtaining a better materials and clinical understanding about changes in structure and elemental composition which we will compare between model systems to in-vivo developing sclerotic tissue.