Development of Secondary and Tertiary Thiol Monomers for Thiol-ene Dental Restorative Materials

项目摘要 牙科材料是最普遍的医疗器械之一，现代几乎所有成年人都使用牙科材料。 世界受益于它的使用。然而，尽管它们具有共同性，但最常用的复合材料是甲基丙烯酸酯， 基聚合物树脂面临许多问题，例如高收缩和收缩应力，吸水性， 水解和酶降解，并且易于浸出未反应的单体。而复合 确实快速治愈，这是临床环境的理想选择，需要细致的程序和环境。的 复合材料必须每次以2-3 mm的增量固化，以确保充分固化并防止应力 发展此外，复合材料的粘附性取决于保持该区域完全干燥，并且即使所有 如果满足这些条件，复合物就不是永久性的解决方案，继发性龋齿经常复发。 因此，虽然复合材料已用于牙齿填充物近40年，但仍然存在关键的缺陷。 需要显著改进的修复材料。 硫醇烯材料在许多方面代表了牙科修复材料的理想候选者。不仅 聚合不受水或氧抑制的影响，但它也同样迅速地进行， 比甲基丙烯酸酯均聚更有效。该反应的机理是显著不同的， 从而导致具有减小的收缩和应力的材料，并且最近已经从材料中去除了酯， 几种硫醇-烯单体以减少它们的降解。有各种各样的可用起始材料 对于硫醇-烯聚合，并且反应在不与其它官能团相互作用的情况下进行。因此，在本发明中， 可以选择单体以减少吸水或水解/酶降解和毒性。 即使有了所有这些优点，还需要做更多的工作来提高使用此 牙科复合材料中的系统。硫醇和烯烃单体可以自发地反应，而没有任何预期的 引发作用-减少单体混合物的保存期。还众所周知，一些硫醇分子 伴随着难闻的气味。由于各种原因，仲硫醇单体不太可能与其它单体反应。 自发地反应并且还具有减少的气味。虽然，关于如何使用 硫醇的取代将影响硫醇-烯反应。 因此，本项目建议通过将 仲硫醇和叔硫醇单体形成硫醇-烯复合物。为了做到这一点，彻底的动力和 必须完成聚合物研究，以便可以评估更高度取代的硫醇的效果。新 将合成伯硫醇、仲硫醇和叔硫醇单体，并将硫醇和烯烃单体库 将被评估为最佳结合到牙科修复复合材料。这些复合材料将是 评价了与常用牙科复合材料相比改善的机械和临床性能。

Project Summary Dental materials are among the most ubiquitous medical devices, with almost all adults in the modern world benefiting from their use. Yet, despite their commonality the most employed composite, a methacrylate based polymer resin, faces many issues such as high shrinkage and shrinkage stress, water sorption, hydrolytic and enzymatic degradation, and is prone to leaching of unreacted monomer. While the composite does cure rapidly as is ideal for clinical settings, meticulous procedures and environments are required. The composite must be cured in increments of 2-3 mm at a time to assure adequate cure and prevent stress development. Further, adhesion of the composite depends on keeping the area completely dry and even if all these conditions are met, the composite is not a permanent solution with secondary caries often recurring. Thus, while composite materials have been used in dental fillings for almost 40 years, there remains a critical need for a significantly improved restorative material. Thiol-ene materials represent an ideal candidate for dental restorative materials in many ways. Not only is the polymerization not susceptible to water or oxygen inhibition, but it also proceeds just as rapidly and more efficiently than a methacrylate homopolymerization. The mechanism of this reaction is significantly different, resulting in a material that has reduced shrinkage and stress and esters have recently been removed from several thiol-ene monomers to reduce their degradation. There are a wide variety of available starting materials for a thiol-ene polymerization, and the reaction proceeds without interacting with other functional groups. Thus, monomers can be chosen to reduce water sorption or hydrolytic/enzymatic degradation and toxicity. Even with all these advantages, more work needs to be done to improve the practicality of using this system in a dental composite. Thiol and alkene monomers can spontaneously react without any intended initiation action – reducing the shelf-life of monomer mixtures. It is also well known that some thiol molecules are accompanied by an unpleasant odor. For a variety of reasons secondary thiol monomers are less likely to spontaneously react and also have a reduced odor. Although, there is still little information regarding how the substitution of the thiol will affect the thiol-ene reaction. Therefore, this project proposes to make an improved dental restorative material by incorporating secondary and tertiary thiol monomers into a thiol-ene composite. In order to do so, thorough kinetic and polymer studies must be completed so the effect from the more highly substituted thiols can be assessed. New primary, secondary, and tertiary thiol monomers will be synthesized and a library of thiol and alkene monomers will be evaluated for the best incorporation into dental restorative composites. These composites will be evaluated for improved mechanical and clinical properties against a commonly used dental composite.