Novel Nanostructured Dental Glass-Ionomers for Advanced Dental Restoratives

描述（由申请人提供）：目前，市售的玻璃离子水门汀（GIC）由于其耐磨性差和机械强度低而未用于I类和II类置换，尽管这些水门汀与复合树脂相比具有许多优点。我们已经证明，新的星形聚酸结构的混合玻璃离子水门汀具有出色的和可比的耐磨性，以及目前的复合树脂的机械强度。此外，纳米填料增强的GIC显示出显着改善的硬度和耐磨性。结合表面改性的纳米填料，上述星形聚合物构建的GIC可以发展成为一种新型的牙科修复体，用于需要耐磨性和高强度的牙齿修复部位。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系统，具有与当前牙科复合树脂相当的耐磨性和机械强度，以响应NIDCR的纳米结构牙科复合修复材料FOA。本研究采用先进的水相ATRP技术，合成了一系列具有高分子表面修饰的星形聚丙烯酸及其纳米粒子。纳米级功能聚合物和填料将被表征并用于构建新型生物相容性高强度光固化GIC。该体系将基于分子量、纳米填料表面上聚合物的长度、聚合物上甲基丙烯酸酯的束缚比、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、硬度和粘度将用作评价的主要筛选工具。耐磨性和断裂韧性将用作二次筛选工具。还将评估其他重要的机械和物理性能。采用MTT法评价新系统的体外生物相容性。该项目将建立在具有强大聚合物合成经验的牙科材料科学家和具有强大牙科材料研究背景的临床牙医之间的持续合作基础上。该项目目标的成功实现将通过提供一种新的有吸引力的粘合剂牙科修复体，对修复牙科和早期龋齿干预领域产生积极影响。该项目还将为生物医学工程学生和牙科材料学生提供理想的培训环境，因为它将使他们能够通过与来自不同学科的合作者的密切互动，发展牙科材料研究的广阔前景。

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.