IMPROVED CHARACTERIZATION OF DENTAL BIOMATERIALS

目前普遍认为， 用于牙科的树脂系统，例如前牙和后牙 需要大量的改进。为了使所需 复合材料的改进，我们必须更充分地了解是什么原因 现有系统的缺陷，需要改进 表征技术。 此外，为了充分评估新的 对于改进复合材料的化学概念， 已经改进了表征技术。例如，一个更好的 我们需要了解在分子水平上发生了什么， 复合材料暴露于口腔的非常侵蚀性的环境中， 腔 考虑到上述情况，本试验性提案有一个新颖的两部分， 推力首先，该提案概述了为发展 电子自旋共振（ESR）成像作为一种非常强大的 在分子水平上观察扩散和变化的方法 复合材料.该方法，迄今尚未探索的牙科复合材料， 提供新的和重要的信息， 牙科材料的特性。第二，我们要证明 ESR成像是一个很好的工具来帮助指导合成， 表征和开发新的化学方法， 牙科和其他生物医学用高性能复合材料 应用. 在最初的努力中，模型（对照）树脂系统和目前的 可用的可见光固化（VLC）复合材料将在37 ℃的水中老化 摄氏度的各种时间段，与水含有可溶性 氮氧化物自旋探针。ESR成像将用于研究非均匀， VLC材料的吸湿膨胀或溶胀特性。 测量扩散速率和/或过程以及 分子水平，由于水的吸附，将是ESR研究的一个领域， 并将结果与重量分析和NMR成像数据进行比较。在 同时，将对ESR技术进行研究，以研究失效 商业和对照牙科生物材料的机制。模型 系统将被配制成比现有的复合材料更疏水， 具有更大的抗蠕变性、改善的抗压强度等，作为 与基于BisGMA的（对照）VLC系统相比。 本研究中开发的表征方法应有助于确定 目前市场上的哪些材料最值得使用， 如何修改它们以实现更好的性能。因此，实现 预期的目标应有助于使牙科椅得到改善， 高性能材料，有助于增强牙齿健康。

It is commonly accepted that the service performance of current composite resin systems used in dentistry, such as anterior and posterior restoratives, need substantial improvement. In order to make needed improvements in composites we must more fully understand what causes deficiencies in existing systems, which calls for improved characterization techniques. In addition, to adequately evaluate new chemical concepts for improved composites it is also very important to have improved characterization techniques. As an example, a better understanding is needed for what happens at the molecular level when composites are exposed to the very aggressive environment of the oral cavity. In consideration of the above, this pilot proposal has a novel two-part thrust. First, the proposal outlines studies for the development of electron spin resonance (ESR) imaging as an extraordinarily powerful method for observing diffusion and changes at the molecular level in composites. The method, heretofore unexplored for dental composites, holds great promise for giving new and significant information on the characteristics of dental materials. Secondly, we propose to demonstrate that ESR imaging is an excellent tool to help guide the synthesis, characterization, and development of new chemistry for improved performance composites used in dentistry and other biomedical applications. In the initial effort, model (control) resin systems and currently available visible light cured (VLC) composites will be aged in water at 37 degrees C for various time segments, with the water containing a soluble nitroxide spin probe. ESR imaging will be used to study non-homogeneous, hygroscopic expansion or swelling characteristics of the VLC materials. Measurement of diffusion rates and/or processes and changes at the molecular level, due to water sorption, will be one area of ESR study, with results compared with gravimetric analysis and NMR imaging data. At the same time, the ESR technique will be examined for study of the failure mechanisms of both commercial and control dental biomaterials. The model system will be formulated to be more hydrophobic than existing composites, have greater creep resistance, improved compressive strength, etc., as compared to BisGMA based (control) VLC systems. Characterization methods developed in this study should help ascertain what materials currently in the market place are most worthy of use and how they may be modified to achieve improved performance. Thus, achieving the intended goals should facilitate bringing to the dental chair improved performance materials, contributing to enhanced dental health.