FOR 2804: The Materials Science of Teeth in Function: Principles of Durable, Dynamic Dental Interphases

当临床需要出现时，牙齿会用不可吸收的生物材料修复。这通常意味着人造牙科材料需要在口腔内恶劣的循环载荷条件下运行多年。最初，牙科医生在放置填充物或牙冠之前移除病理性/断裂的组织(如龋齿)。为了保持修复体的位置，修复体和剩余的健康牙齿组织之间必须建立密切的联系。良好的接触是通过形成由具有不同微观形貌、成分和性能的中间层组成的“中间带”、3D片状结构来实现的。尽管有大量的聚合物、陶瓷和金属化合物，但人工构建的牙齿修复材料中的间隙永远不会像天然修复材料那样好，后者通常由简单的轻有机和矿物成分组成。造成这种差异的原因人们知之甚少。因此，牙医经常过度设计或未充分利用容错材料。我们认为，更深入地了解区域间失效在哪里以及如何开始，以及对底层微观结构的高分辨率分析，可以为设计更持久的区域间铺平道路。在这里，我们建议成立一个研究单位“InterDent”，作为材料科学家、工程师和牙科临床医生在六个互补项目中进行亲密互动的平台。虽然项目1将解决牙本质中化学老化的特性和动力学，但项目2将揭示牙本质-牙本质-牙本质结合处令人印象深刻的抗剪切疲劳的原理。项目3试图从填充物和牙本质之间糟糕的区间中学习，同时试图对修复体附近的龋齿预测指标进行基准测试。项目4检查附着在牙科修复体上的生物膜的物理化学线索。项目5主要集中在牙冠材料和水泥的主要类别，以生成大量不同类型损伤的高分辨率模拟。项目6评估在有限的根管治疗空间内的修复硬化的动力学。通过在跨学科研究人员之间转移技术诀窍和数据，我们将确定预测退化所需的关键参数，我们希望将这些参数反馈到临床。位于柏林的InterDent的独特环境将先进的材料科学实验室与牙科临床医生结合在一起，是开展鼓舞人心的合作的理想沃土，从而在InterDent领域进行了新颖的观察。协调项目的一个主要目标是在各学科之间建立一种协作文化，以便更好地了解区域间现象，并最终更好地进行牙科治疗。

When the clinical need arises, teeth are restored with non-resorbable biomaterials. This usually means that man-made dental materials need to operate for many years under harsh, cyclic loading conditions in the mouth. Initially, the dental surgeon removes pathologic/fractured tissue (e.g. caries) before placing fillings or crowns. To retain the restorations in place, intimate contacts must become established between the restorations and the remaining healthy tooth tissues. Good contact is achieved through formation of ‘interzones’, 3D sheet-like structures comprising intermediate layers with distinct micro-morphologies, compositions and properties. Despite a large range of polymer, ceramic and metal compounds, interzones in artificially constructed tooth restorations are never as good as their natural counterparts that are usually made of simple light organic and mineral components. The reasons for this discrepancy are poorly understood. As a result, dentists often overdesign or underutilize defect-tolerant materials. We propose that a deeper understanding of where and how interzone failure starts, and high resolution analysis of the underlying microstructures can pave the way to designing more durable interzones. Here we propose a research unit "InterDent" that will serve as a platform where materials scientists, engineers and dental clinicians intimately interact within six complementary projects. Whereas project 1 will address the properties and dynamics of chemical aging in dentine, project 2 will unravel the principles of the impressive shear fatigue resistance of the cemento-dentine-junction. Project 3 tries to learn from poor interzones between fillings and dentine, while attempting to benchmark predictors of caries near restorations. Project 4 examines the physical-chemical clues of biofilms attached to dental restorations. Project 5 focuses on the main classes of crown materials and cements to generate a large number of high-resolution simulations of different kinds of damage. Project 6 assesses the dynamics of restoration hardening in the confined space of root canal treatment. By transfer of know-how and data between interdisciplinary researchers, we will identify key parameters needed to predict degradation which we hope to feed back into the clinic. The unique setting of InterDent in Berlin combining advanced material science laboratories with dental clinicians is the ideal fertile soil for an inspiring cooperation leading to novel observations in the fields of InterDent. A major objective of the coordination project is to establish a culture of collaboration between the disciplines for the benefit of a better understanding of interzone phenomena and ultimately better dental treatment.