Dental Composite Materials Based on Photoinitiated Thiol-Vinyl Sulfone Reactions

描述(申请人提供)：牙科修复体是概念上最简单的生物材料之一--本质上需要以美学上可接受的方式恢复机械功能。然而，尽管概念简单，但一系列复杂且经常相互冲突的材料、生物、固化和反应特性需要一系列不太理想的解决方案。每年进行数以亿计的修复，这些修复过早失败导致需要更多的修复，包括偶尔移除额外的健康牙齿结构。对简单、生物相容、易于操作的美容牙科修复剂的需求推动了社区转向聚合物复合材料，这种聚合物复合材料很容易在原位反应，通常通过光引发，以产生外观类似牙齿的高模、高强度的复合材料结构。尽管这些材料很重要，但这些体系的树脂相(即可聚合组分)自几十年前引入以来基本保持不变。以二甲基丙烯酸酯为基础的树脂通常用于牙科修复材料，存在严重的问题；它们不能实现甲基丙烯酸酯的完全转化，因此留下了大量可以被提取到口腔环境中的材料。此外，这些材料容易在用于固化材料的聚合/固化过程中产生显著的收缩和收缩应力。因此，在这里，我们提出了一种革命性的新方法，基于亲核剂催化的硫醇-乙烯基砜网络形成反应来获得牙科材料。提出的硫醇-乙烯基砜牙科复合体系将显著改善传统的甲基丙烯酸盐基复合体系的生物、化学反应和力学行为。基于令人兴奋的初步结果，这些结果表明，通过这种高效、快速的反应能够实现完全的官能团转化；形成的聚合物具有适当的机械行为；低收缩和低应力；以及从树脂中消除具有酶活性的官能团，我们假设由这种硫醇-乙烯基砜反应形成的树脂是牙科修复材料的理想候选者。总体目标是开发和评估基于亲核催化的硫醇-乙烯基砜Michael加成反应的牙科复合材料，包括开发合适的单体和功能化填料，开发用于这些树脂的高活性光引发剂系统，以及展示可接受的疲劳、可抽提物、生物相容性、降解和其他基本的短期和长期复合材料行为。最终，总体目标是建立这些基于硫醇-乙烯基砜的复合材料，作为牙科复合材料领域的颠覆性变化。我们将在这一授权期内证明，这些材料能够在长期、具有环境挑战性的测试条件下显著减少可萃取物、膨胀、降解和磨损，从而使使用寿命增加两倍以上。

DESCRIPTION (provided by applicant): Dental restorations represent one of the conceptually simplest biomaterials - essentially requiring the restoration of mechanical function in an aesthetically acceptable manner. Yet, despite that conceptual simplicity, an array of complex and often conflicting material, biological, curing and reaction properties necessitate a series of suboptimal solutions. Hundreds of millions of restorations are performed each year and premature failure of these restorations results in the need for a far greater number of restorations, including the occasional removal of additional healthy tooth structure. The need for simple, biocompatible, easily manipulated aesthetic dental restoratives has pushed the community towards polymeric composites that are readily reacted in situ, generally by photoinitiation, to yield a high modulus, high strength composite structure that is tooth-like in appearance. Despite the importance of these materials, the resin (i.e., the polymerizable component) phase of these systems has remained largely unchanged since its introduction several decades ago. The common use of dimethacrylate-based resins for dental restorative materials is plagued by critical problems; they do not achieve complete conversion of the methacrylates and thus leave a great deal of material that can be extracted into the oral environment. Further, these materials are prone to significant shrinkage and shrinkage stress that arises during the polymerization/curing process that is used to set the material. Thus, here, we propose a revolutionary new approach to dental materials based on the nucleophile- catalyzed thiol-vinyl sulfone network forming reaction. The proposed thiol-vinyl sulfone dental composite system will significantly improve upon the biological, chemical reaction and mechanical behavior of traditional methcrylate based composite systems. Based on exciting preliminary results that demonstrate the ability to achieve complete functional group conversion via this highly efficient, rapid reaction; appropriate mechanical behavior from the polymers formed; low shrinkage and stress; and the elimination of enzymatically reactive functional groups from the resin, we hypothesize that resins formed by this thiol-vinyl sulfone reaction represent ideal candidates as dental restorative materials. The overall aim is to develop and evaluate dental composites based on the nucleophile catalyzed thiol-vinyl sulfone Michael addition reaction that will include the development of appropriate monomers and functionalized fillers, the development of highly reactive photoinitiator systems for these resins, and the demonstration of acceptable fatigue, extractables, biocompatibility, degradation and other essential short- and long-term composite behavior. Ultimately, the overall aim is to establish these thiol-vinyl sulfone-based composites as a disruptive change in the dental composite field. We will demonstrate over the course of this grant period that these materials are capable of achieving more than a two-fold increase in service lifetime based on dramatically reduced extractables, swelling, degradation and wear in longterm, environmentally challenging testing conditions.