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设备之一，几乎所有的成年人都在现代 世界从它们的使用中受益。然而，尽管它们有共同之处，但使用最多的复合材料是甲基丙烯酸酯 以聚合物为基础的树脂面临着许多问题，如高收缩和收缩应力，吸水， 水解性和酶性降解，易发生未反应单体的淋溶。而复合体 快速治愈是临床环境的理想选择，需要一丝不苟的程序和环境。这个 复合材料必须一次固化2-3毫米，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，即使所有 如果满足这些条件，复合体不是永久性的解决方案，继发性龋病往往会复发。 因此，尽管复合材料用于牙齿填充已有近40年的历史，但仍有一个关键的 需要一种显著改进的修复材料。 硫醇-烯材料在许多方面都是牙科修复材料的理想候选者。不仅是因为 聚合不受水或氧气的抑制，但它也同样快速和更快地进行。 比甲基丙烯酸酯均聚更有效。这个反应的机理有很大的不同， 从而产生一种减少收缩和应力的材料，并且酯最近从 几种硫醇-烯单体以减少其降解。可供选择的起始材料种类繁多 对于硫醇-烯聚合，反应进行而不与其他官能团相互作用。因此， 可以选择单体来降低吸水性或水解性/酶解性和毒性。 即使有了所有这些优点，还需要做更多的工作来提高使用这一技术的实用性 牙科复合体中的系统。硫醇和烯烃单体可以在没有任何故意的情况下自发反应 引发作用--缩短单体混合物的保质期。众所周知，一些硫醇分子 伴随着难闻的气味。由于各种原因，二次硫醇单体不太可能 会自发反应，气味也会减少。尽管，关于这一事件如何发生的信息仍然很少 硫醇的取代会影响硫醇-烯反应。 因此，本项目建议通过在牙科修复材料中加入 仲硫醇和叔硫醇单体形成硫醇-烯复合材料。为了做到这一点，彻底的动力和 聚合物研究必须完成，这样才能评估取代程度更高的硫醇的影响。新的 将合成初级、二级和三级硫醇单体，以及硫醇和烯烃单体的库 将进行评估，以最好地融入牙科修复复合材料。这些复合材料将是 与常用的牙科复合材料相比，评估其机械性能和临床性能的改善。

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.