Novel surface treatment of fillers for dental composites

描述（由申请人提供）：在可预见的未来，牙齿健康的各个部分的修复将继续成为牙科的中心焦点。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远远低于牙科汞合金。复合材料的关键限制与树脂基体形成过程中的收缩应力发展以及树脂与填料之间附着物的建立和长期耐久性有关。虽然复合材料的许多进步都来自填料组成和粒度的选择，但树脂和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一个界面区域的潜力，该界面区域与牙科复合材料中使用的传统γ -甲基丙烯氧基丙基三甲氧基硅烷的界面区域有很大不同。在具体目标1：控制缺乏可聚合甲基丙烯酸酯基团的功能化硅烷的浓度将用于产生小颗粒填料和微填料的有效表面覆盖。硅烷化过程将被详细研究，因为在没有甲基丙烯酸酯基团的情况下，可以使用明显不同的应用程序。在具体目标2中：附加的功能将用于共价连接预形成的低聚物/聚合物链。表面系链在疏水性、柔韧性和长度方面可以有很大的变化。在具体目标3中，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，所得复合材料将被评估，合理的期望是，这里开发的替代偶联剂将通过物理缠结和直接共聚提供高效和稳定的树脂-填料附着。基于更高的填料负载、更高的水解稳定性、更高的耐磨性、更好的断裂韧性和降低聚合收缩应力，复合材料得到了显著的改进；所有这些都不损害机械强度性能。虽然偶联剂只占牙科复合材料配方的一小部分，但通过改变该界面区域，复合材料的性能似乎有实质性的、临床相关的好处。积极的初步数据提供了鼓励，这种纳米技术方法的树脂填料界面可以提供广泛适用的功能增强和寿命广泛使用的牙科修复体。

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.