Novel surface treatment of fillers for dental composites

描述(由申请人提供)：在可预见的未来，修复原本健康的牙齿的龋齿部分将继续是牙科的中心焦点。尽管复合材料在过去几十年中有了显著的改进，但复合材料的预计使用寿命仍然比牙科银汞合金短得多。复合材料的关键局限性与树脂基质形成过程中的收缩应力发展以及树脂和填料之间的附着物的建立和长期耐久性有关。虽然复合材料的许多进展来自于填料组成和粒度的选择，但树脂与填料之间的偶联剂界面却很少受到关注。这项拟议的研究将开发和评估与传统牙科复合材料中使用的伽马-甲基丙烯氧丙基三甲氧基硅烷截然不同的界面区域的潜力。具体目标1：控制缺乏可聚合甲基丙烯酸酯基团的官能化硅烷的浓度，以产生有效的小颗粒填料和微填料的表面复盖物。将详细研究硅烷化过程，因为在没有甲基丙烯酸酯基团的情况下，可以使用显著不同的应用程序。在具体目标2中：附加的官能团将用于共价连接预制低聚物/聚合链。表面系链链在疏水性、柔韧性和长度方面可以有显著的变化。具体目标3：聚合物刷表面改性填料将与传统的甲基丙烯酸酯基牙科树脂配制，并将对所产生的复合材料进行合理的评估，期望这里开发的替代偶联剂将通过物理缠绕和直接共聚提供高效和稳定的树脂-填料附着。基于更高的填料装载量、更大的水解稳定性、更高的耐磨性、更好的断裂韧性和更低的聚合收缩应力，复合材料有了显著的改进；所有这些都不影响机械强度性能。虽然偶联剂只占牙科复合材料配方的一小部分气味，但通过改变界面区域，似乎可以在复合材料性能方面获得实质性的、临床相关的好处。积极的初步数据鼓舞着，这种树脂-填充物界面的纳米技术方法可以在广泛使用的牙科修复材料的功能和寿命方面提供广泛适用的增强。

DESCRIPTION (provided by applicant):The restoration of carious portions of otherwise sound teeth will continue to be a central focus of Dentistry into the foreseeable future. In spite of the significant improvements in composites over the last few decades, the projected service life of composite materials remains considerably less than that of Dental amalgams. Critical composite materials limitations are associated with shrinkage stress development during resin matrix formation and the establishment and long-term durability of the attachment between resin and filler. While many of the advances in composites have come from the selection of filler composition and particle size, the coupling agent interface between the resin and filler has received remarkably little attention. This proposed investigation will develop and evaluate the potential of an interfacial region that is dramatically different from that available with the conventional gamma-methacryloxypropyltrimethoxysilane used in Dental composites. In Specific Aim 1: controlled concentrations of functionalized silanes lacking polymerizable methacrylate groups will be applied to yield efficient surface coverage of small particle filler and microfiller. The silanization process will be studied in detail since significantly different application procedures can be used in the absence of methacrylate groups. In Specific Aim 2: the appended functionality will be used to covalently attach preformed oligomeric/polymeric chains. The surface-tethered chains can be significantly varied in terms of hydrophobicity, flexibility and length. In Specific Aim 3: the polymer brush surface-modified fillers will be formulated with traditional methacrylate-based Dental resins and the resulting composites will be evaluated with the reasonable expectation that the alternative coupling agents developed here will provide efficient and stable resin-filler attachment through both physical entanglements and direct copolymerization. Significant improvements are posited in composite materials based on higher filler loading, greater hydrolytic stability, increased wear resistance, improved fracture toughness and reduced polymerization shrinkage stress; all without compromise to mechanical strength properties. While the coupling agent makes up only a smell fraction of the Dental composite formulation, there appears to be substantial, clinically relevant benefits in composite performance that can potentially be obtained by changes in this interfacial region. Positive preliminary data offer encouragement that this nanotechnology approach to the resin-filler interface can provide broadly applicable enhancements in function and longevity of widely used Dental restoratives.