The effect of inorganic trace elements on dentin apatite

非技术摘要：我们的牙齿是由硬组织组成的，包括牙釉质和牙本质。牙本质是牙釉质外层下面的部分，负责牙齿的机械强度。牙本质主要由一种名为羟基磷灰石的化合物组成，它由钙、磷和氢氧化物离子组成。在特定条件下，羟基磷灰石中的钙离子可以被其他大小相近的离子所取代。这些取代可能会影响羟基磷灰石的机械和结构特性，从而影响牙本质。虽然已经对牙釉质和骨骼等材料进行了类似的研究，但这项研究侧重于牙本质，到目前为止，它还没有得到太多关注。这项研究的目的是研究牙本质羟基磷灰石在不同离子溶液存在下的行为以及它们是否改善了它的性能。方法探索羟基磷灰石的各种结构和力学性能。与他们的研究工作相结合，首席研究员提出了一项教育倡议，包括为本科生开发牙科材料课程，并为高中生组织研讨会和研讨会。这项基础性研究可能会产生深远而广泛的影响，因为它最终可能导致新的干预措施来提高牙本质的强度，特别是在硬组织可能因糖尿病、类风湿性关节炎、心血管疾病和多发性硬化症等疾病而受损的情况下。技术摘要：本研究项目旨在调查无机微量矿物(IoTM)对牙本质羟基磷灰石(HAP)结构和力学性能的影响，同时为不同教育水平的学生开展多种教育和推广活动。这项拟议的项目旨在调查物联网，特别是锰、铜和锂对牙本质的结构和力学性能的影响，牙本质是牙齿的重要组成部分。通过采用多学科的方法，结合材料科学、生物学和生物化学，该团队试图扩大对微量矿物如何影响牙本质材料特性的理解。本研究的研究目标是回答以下问题：(1)IoTM(在牙本质中测量，无论是自然发生的还是通过外部/内部暴露)如何影响牙本质结构，进而影响其机械性能？(2)什么结构特性驱动机械变化，这些变化如何随IoTM类型(Mn、Cu或Li)和暴露时间的不同而变化？这些目标将通过先进的成像和光谱技术实现，使用X射线衍射仪、短角/广角X射线散射、电感耦合等离子体质谱和扫描电子显微镜来研究IoTM取代的HAP、晶体性质和晶格性质。还将测试力学性能，包括塑料参数和溶解度，以确定使用人体模型的物联网暴露。除了科学研究，这个项目还包含了重要的教育目标。它旨在促进牙科材料科学的跨学科研究，培养本科生对STEM领域的兴趣，并为STEM中代表性不足的少数民族和妇女提供机会。这项研究的结果可以促进改进技术和生物材料的开发，从而加强对患有影响微量矿物质调节的条件的个人的牙科治疗。同时，它将为矿化组织领域的科学知识做出贡献，并促进STEM教育倡议。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical Abstract:Our teeth are made of hard tissues, including enamel and dentin. Dentin is the part under the outer layer of enamel and is responsible for the mechanical strength of teeth. Dentin is mostly composed of a compound called hydroxyapatite, which consists of calcium, phosphate, and hydroxide ions. Under specific conditions, the calcium ions in hydroxyapatite can be substituted by other ions of similar size. These substitutions may impact hydroxyapatite's mechanical and structural properties and, consequently, dentin. While similar studies have been conducted on materials like enamel and bones, this research focuses on dentin, which has yet to receive much attention thus far. The goal of this study is to study how dentinal hydroxyapatite behaves in the presence of different ionic solutions and if they improve its properties. Methods exploring various structural and mechanical properties of hydroxyapatite will be employed in this study. In conjunction with their research efforts, the principal investigator proposes an educational initiative that involves developing a curriculum on dental materials for undergraduate students and organizing workshops and seminars for high school students. This foundational study can have far-reaching broader impacts, as it can eventually lead to new interventions that improve the strength of dentin, especially as hard tissues may be compromised due to diseases such as diabetes, rheumatoid arthritis, cardiovascular disease, and multiple sclerosis.Technical Abstract:This research project aims to investigate the influence of inorganic trace minerals (IoTM) on the structure and mechanical properties of dentinal hydroxyapatite (HAp) while engaging in multiple education and outreach activities for students at various education levels. The proposed project aims to investigate the influence of IoTM, specifically Mn, Cu, and Li, on dentin's structure and mechanical properties, a vital component of teeth. By employing a multidisciplinary approach, combining materials science, biology, and biochemistry, the team seeks to expand the understanding of how trace minerals impact dentin's material properties. The research objectives of this study are to answer the following questions: (1) How does IoTM (as measured in the dentin, either occurring naturally or through extrinsic/intrinsic exposure) affect dentin structure and, in turn, its mechanical properties? (2) What structural properties drive the mechanical changes, and how do these changes vary according to IoTM type (Mn, Cu, or Li) and exposure duration? These objectives will be accomplished via advanced imaging and spectroscopy techniques using X-Ray diffractometry, short/wide angle X-Ray scattering, inductively coupled plasma mass spectrometry, and scanning electron microscope to study the IoTM substitution in HAp, crystal properties, and lattice properties. The mechanical properties, including the plastic parameters and solubility, will also be tested to determine the IoTM exposure using human models. In addition to the scientific research, this project incorporates important educational goals. It seeks to promote interdisciplinary studies in dental material science, foster interest in STEM fields among undergraduate students, and provide opportunities for underrepresented minorities and women in STEM. The outcomes of this research can facilitate the development of improved technologies and biomaterials, leading to enhanced dental treatments for individuals with conditions impacting trace mineral regulation. Simultaneously, it will contribute to scientific knowledge in the field of mineralized tissues and promote STEM education initiatives.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.