Application of Nanogel-modified Resins for Improved Polymeric Dental Materials

描述（由申请人提供）：在美国每年进行的超过10亿次牙科修复治疗中，大多数涉及树脂粘合复合材料的放置，并且承认牙医的大部分时间都花费在修改和更换这些修复体上，因此显然需要具有改进临床性能的材料。复合修复体不仅比牙科汞合金具有美学上的优势，而且还提供了一种将修复体粘附到牙本质和牙釉质上的方法。然而，由于聚合收缩应力从放置时起就会挑战这个关键界面，因此目前无法可靠地获得强大，完整的边缘。最近发展了一种高度通用的技术，用于制备纳米级（5 - 100纳米）聚合物颗粒，控制其分支，化学和反应位点的放置。这些反应性纳米凝胶可以很容易地以高浓度分散在二级单体中，然后渗透并随后与预聚物添加剂共聚。这种方法大大减少了聚合收缩和应力，并证明了提高牙科树脂和复合材料模型强度的能力。该项目将积极的初步结果扩展到用于修复应用的高填充、低应力、纳米凝胶改性复合材料的实际示例中，同时还将开发依赖互穿聚合物网络的新型密封材料，以在放置过程中显著降低游离单体的水平。基于纳米凝胶的生物活性密封剂，具有抗菌和潜在的mmp抑制特性，也将被开发和展示。该应用程序围绕三个目标构建：i)纳米凝胶合成的基础研究，旨在生产具有可预测性质的可控纳米凝胶结构，主要关注单体基质中高纳米凝胶含量与实际有用的粘度和光学性质之间的平衡；Ii)纳米凝胶在

DESCRIPTION (provided by applicant): With a majority of the more than 100,000 million dental restorative treatments performed in the US each year involving the placement of resin-bonded composite materials, and the acknowledgement that a large portion of a dentist's time is consumed with revising and replacing these restorations, there is a clear need for materials with improved clinical performance. Composite restoratives not only hold an esthetic advantage over dental amalgams, but they offer a means to adhesively bond the restoration to dentin and enamel. However, due to polymerization shrinkage stresses that challenge this critical interface from the time of placement, a strong, intact margin can not currently be reliably obtained. A highly versatile technique has been developed recently for preparing nano-scale (5 - 100 nm) polymeric particles with control over branching, chemistry and reactive site placement. These reactive nanogels can be dispersed readily at high concentrations in secondary monomers, which then infiltrate and subsequently copolymerize with the prepolymer additives. This approach has provided substantial reductions in polymerization shrinkage and stress, as well as a demonstrated ability to improve the strength of a model dental resin and composite. The proposed project would extend the positive preliminary results into practical examples of highly filled, low stress, nanogel-modified composites for restorative applications while also developing new sealant materials that rely on interpenetrating polymer networks to achieve dramatically reduced levels of free monomer during placement. Bioactive sealants based on nanogels that display anti-bacterial and potentially MMP-inhibiting properties will also be developed and demonstrated. The application is constructed around three aims: i) fundamental studies of nanogel synthesis designed to produce well controlled nanogel structures with predictable properties with a primary focus on a balance between high nanogel contents in monomeric matrices with practically useful viscosities and optical properties; ii) application of nanogels in dental composites where greater than proportional reductions in stress, relative to the nanogel content, will be sought while also improving the fracture toughness of potentially bulk filling composites that combine high loading levels of both nanogel and novel surface-treated inorganic fillers; and iii) use of nanogels to create sealant materials with interpenetrating polymer networks that form with high conversion and a reduced sensitivity to oxygen inhibition, which means more stable materials with much less leachable compound release. The sealant material platform will be further extended to demonstrate the potential bioactivity of polymers with chemically integrated nanogels that convey bactericidal and MMP- inhibition properties.