Novel Nanostructured Dental Glass-Ionomers for Advanced Dental Restoratives

描述（由申请人提供）：目前，市面上没有一种玻璃离子聚合物胶合剂（gic）用于I类和II类修复体，因为它们的耐磨性差，机械强度低，尽管这些胶合剂比复合树脂有许多优点。我们已经证明，新型星形聚酸构建的杂化玻璃离子聚合物水泥具有优异的耐磨性和与现有复合树脂相当的机械强度。此外，纳米填料增强的GIC具有明显的硬度和耐磨性。结合表面改性纳米填料，上述星形聚合物构建的GIC可能发展成为一种新型的牙科修复体，用于需要耐磨和高强度修复的部位。本研究的目的是开发一种新型的生物相容性纳米结构光固化玻璃离子体系，其耐磨性和机械强度与目前的牙科复合树脂相当，以响应NIDCR对纳米结构牙科复合修复材料的FOA。本研究将采用先进的水溶液ATRP技术合成一系列具有聚合物表面修饰的星形聚丙烯酸及其纳米颗粒。纳米功能聚合物和填料将被表征并用于构建一种新型的生物相容性高强度光固化GIC。该体系将根据分子量、聚合物在纳米填料表面的长度、甲基丙烯酸酯在聚合物上的系聚比、纳米填料负载比、总填料粉末/聚合物液体比、工作粘度和引发剂体系的效率进行优化。抗弯强度、硬度和粘度将作为评价的主要筛选工具。耐磨性和断裂韧性将作为二级筛选工具。其他重要的机械和物理性能也将被评估。新系统的体外生物相容性将采用MTT法进行评估。该项目将建立在具有丰富聚合物合成经验的牙科材料科学家和具有丰富牙科材料研究背景的临床牙医之间持续合作的基础上。该项目的成功实现将提供一种具有吸引力的新型粘接牙科修复体，对修复牙科和早期龋齿干预领域产生积极的影响。该项目也将为生物医学工程专业的学生和牙科材料专业的学生提供一个理想的训练环境，因为它将使他们通过与不同学科的合作者的密切互动，发展牙科材料研究的广阔视野。

DESCRIPTION (provided by applicant): Currently, none of the commercially available glass-ionomer cements (GICs) are being used for Class I and II restorations due to their poor wear-resistance and low mechanical strengths, although these cements have numerous advantages over composite resins. We have demonstrated that novel star-shape polyacid-constructed hybrid glass-ionomer cement exhibits outstanding and comparable wear resistance as well as mechanical strengths to current composite resins. Further, nanofiller-strengthened GIC showed significantly improved hardness and wear-resistance. Combined with surface-modified nanofillers, the above star-shape polymer-constructed GIC may be developed into a novel dental restorative for sites requiring wear-resistance and high-strength restorations. The objective of this research is to develop a novel biocompatible nanostructured light-cured glass-ionomer system with comparable wear-resistance and mechanical strengths to current dental composite resins, in response to NIDCR's FOA for Nanostructured Dental Composite Restorative Materials. In this research, a series of starshape poly (acrylic acid)s and nanoparticles with polymer surface modification will be synthesized using advanced aqueous ATRP technology. Both nanosized functional polymers and fillers will be characterized and used to construct a novel biocompatible high-strength light-cured GIC. The system will be optimized based upon molecular weight, length of the polymer on nanofiller surface, tethering ratio of methacrylate on the polymer, nanofiller loading ratio, total filler powder/polymer liquid ratio, working viscosity, and efficiency of the initiator system. Flexural strength, hardness and viscosity will be used as primary screening tools for evaluation. Wear resistance and fracture toughness will be used as secondary screening tools. Other important mechanical and physical properties will also be evaluated. In vitro biocompatibility of the new system will be evaluated using MTT assay. This project will build on an ongoing collaboration between a dental materials scientist with strong polymer synthesis experience and a clinical dentist with strong dental materials research background. Successful achievement of the goals of this project will positively impact the fields of Restorative Dentistry and early caries intervention by providing a new attractive adhesive dental restorative. This project will also provide an ideal training environment for biomedical engineering students and dental materials students because it will allow them, through close interactions with the collaborators from different disciplines, to develop a broad perspective on dental materials research.