Understanding and enhancing the mechanical performance of bioinspired zirconia-based dental materials

龋齿等口腔疾病是影响世界40%以上人口和英格兰30%以上有齿成年人的主要医疗挑战之一。这种疾病可能会导致牙齿功能丧失，从而损害饮食，并对一般健康造成不良后果。它还会导致牙齿失去美感，对患者的社会活动产生不利影响。牙冠可以恢复功能和美观(例如，瓷贴面氧化锆框)，这也有助于防止患者经历疼痛、敏感和感染。由于英国人口老化，他们需要复杂的牙齿护理来恢复和维护他们的牙齿，以及英国超过37%的有牙齿的成年人拥有一个或多个牙冠，因此对具有更长寿命的患者专用牙科修复产品(例如牙冠)的需求不断增长。尽管机械性能不断提高，传统的瓷贴面氧化锆支架仍存在较高的故障率(3至5年内约为6%-15%)。这些牙冠的主要失效模式是瓷贴面的近界面碎裂，这是由于在咀嚼过程中施加在牙冠的咀嚼或研磨表面的载荷(称为咬合载荷)。牙冠的失败会给患者带来广泛的不适，并对患者和临床医生都有很高的成本影响。因此，为了缓解这一问题，开发具有显著提高抗裂性的新型无瓷氧化锆基牙科修复材料是非常必要的。这些复合材料的灵感来自于天然牙齿，它们具有复杂的结构，使其具有非凡的机械性能，特别是抗断裂性能--尤其是在牙釉质中。牙釉质已被证明具有渐变的微结构和与弹性支持牙本质的极强的界面粘结。在这个项目中，我们建议了解和改进具有生物启发功能梯度和织构微结构的新型氧化锆基复合材料的力学性能。我们的目标是模拟天然牙釉质的结构和显著的机械性能。机械性能的提高将建立在对生物启发的微结构特征在决定机械性能中的作用以及如何通过微结构优化来增强性能的基本了解的基础上。为了实现这一目标，我们将开发和实施先进的微尺度机械和结构表征技术以及微观机械建模。我们将与学术和行业合作者密切合作，并接受临床投入。该项目的成果将指导下一代牙科产品开发周期的仿生材料设计和优化的制造和加工。患有牙病的患者将从这项工作中受益，通过对健康状况、个人幸福感和生活质量的深远改善。

Oral disease such as tooth decay is one of the major healthcare challenges that affects over 40% of the world's population and over 30% of dentate adults in England. Such disease can lead to a loss of function in teeth that can impair diet and have undesirable consequences for general health. It can also lead to a loss of aesthetics in teeth, which adversely influences social activity of the patients. Both function and aesthetics can be restored with dental crowns (e.g. porcelain-veneered zirconia frameworks), which can also help prevent patients from experiencing pain, sensitivity and infection. Driven by the ageing population in the UK who need complex dental care to restore and maintain their teeth throughout their lives, as well as the fact that over 37% of dentate adults in England have one or more crowns, there has been a growing demand for patient specific dental restorative products (e.g. dental crowns) with increased longevity. Despite a continuous improvement in the mechanical performance, the conventional porcelain-veneered zirconia frameworks still suffer from a high failure rate (approximately 6-15% over a 3- to 5- year period). The primary failure mode of these dental crowns is near-interface chipping of the porcelain veneer, due to the loads that are applied to the chewing or grinding surface of the crown during mastication (referred to as occlusal loads). Failure of dental crowns can cause extensive discomfort to patients and have high cost implications for both patients and clinicians. To alleviate the problem, it is therefore highly desirable to develop novel porcelain-free zirconia-based dental restorative materials with significantly improved resistance to cracking. Inspiration for these composites can come from natural teeth, which have an intricate architecture giving them remarkable mechanical properties, especially the resistance to fracture - particularly in tooth enamel. Tooth enamel has been shown to have graded microstructure and extraordinarily strong interfacial bonding to the resilient supporting dentine. In this project, we propose to understand and improve the mechanical performance of novel zirconia-based composites with bioinspired functionally graded and textured microstructures. Our aim is to mimic the structure and remarkable mechanical properties of natural tooth enamel. The improvement of the mechanical performance will be based on a fundamental understanding of the role of bioinspired microstructural features in determining the mechanical properties, and how the properties can be enhanced by microstructural optimisation. To achieve this, we will develop and implement advanced micro-scale mechanical and structural characterisation techniques and micromechanical modelling. We will be working in close collaboration with academic and industrial collaborators and receive clinical input. The outcomes of this project will direct the manufacturing and processing towards biomimetic materials design and optimisation for the development cycle of the next generation dental products. Patients suffering from dental disease will benefit from this work through far-reaching improvements in the state of health, personal happiness and quality of life.