A one-part free radical initiator system to enable visible light-activated polymerization with post-exposure dark cure and extensive, athermal shadow cure behavior

一种单组分自由基引发剂系统，可实现可见光活化聚合，并具有曝光后暗固化和广泛的无热阴影固化行为

• 批准号: 9903283
• 负责人: JEFFREY W. STANSBURY
• 金额: $ 18.77万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9903283
• 关键词: Address; Adhesions; Adhesives; Amines; Amplifiers; Behavior; Clinical; Clinical Services; Composite Resins; Consumption; Coupled; Dental; Dental Cavity Preparation; Dental Materials; Dental caries; Dentistry; Dentists; Development; Dimensions; Exposure to; Failure; Fracture; Free Radicals; Goals; Hour; Lead; Life; Light; Link; Longevity; Maintenance; Measures; Methods; Orthodontic Brackets; Output; Oxidants; Oxidation-Reduction; Oxides; Pattern; Performance; Peroxides; Phase; Plant Resins; Polymers; Price; Process; Production; Property; Psychological reinforcement; Reaction; Reducing Agents; Sampling; Stress; Surface; Syringes; System; Techniques; Technology; Terminology; Thick; Time; Tooth structure; Visible Radiation; attenuation; base; clinically relevant; composite restoration; design; direct application; improved; irradiation; monomer; novel; novel strategies; photocuring; photolysis; photopolymerization; polymerization; polymerization stress; prevent; reaction rate; repaired; restoration; restoration placement; restorative composite; restorative material; restorative treatment; success

With a majority of the more than 160 million dental restorative treatments performed in the US each year involving the placement of resin-bonded composite materials, and the acknowledgement that a large portion of a dentist’s time is consumed with revising and replacing these restorations, there is a clear need for materials with improved clinical performance. The relatively short average clinical lifespan (~6 years), particularly for large restorations, is not just inefficient and expensive, but each revision escalates to more invasive treatment. The primary reasons for the failure rate of restorations are fracture or loss of the composite as well as secondary caries. These problems are all potentially linked to inadequate curing during placement of the restoration since polymer properties are correlated with degree of conversion while adhesion to the tooth and the associated reinforcement of a compromised tooth are also dependent on the extent of cure of the composite resin. Uncured monomer leaching from a restoration is known to promote more aggressive bacterial activity in the vicinity of a restoration, which further underscores the need for well cured composites. It is notable that there are significant discrepancies in the clinical service life of similar commercial composite materials, which indicates that the reliable placement of the materials is highly technique sensitive. The goal here is to design novel photoinitiating systems capable of delivering free radicals for reliable polymerization beyond the temporal and spatial footprint of a visible curing light. The intended clinically relevant application is for the direct placement of dimensionally thick, highly filled composite restorative materials in which substantial light attenuation and/or shadow patterning is encountered. These heavy-body materials cannot be accommodated in dual-cure auto-mixing syringes. The product of this proposal could alleviate all concern of incompletely photocured composite restorations by development of completely new photo-activated redox polymerization initiation systems that in one version can augment the initial cure in under-cured regions of a composite by engaging a dark curing process that continues beyond exposure to the curing light. Our early results demonstrate limited photopolymerizations reaching only 10% conversion during direct light exposure that can then progress to full conversion of colorless polymer in the ensuing dark phase. Alternatively, another version of the initiator is expected to produce full conversion following a brief activation by visible light even within regions that received no exposure from the curing light. If successful, this demonstration project will introduce a breakthrough in photocuring that would dramatically increase depth of cure and provide full assurance of complete conversion in dental composite and resin cement photopolymerizations. In addition to the obvious benefits of assured full conversion and optimized properties, other advantages such as reduced polymerization stress and improved adhesive bonding due to a more gradual polymerization process at the composite base may be realized. Success here would represent a tremendously important advance in photopolymerization that would undoubtedly extend beyond dentistry.

在美国每年进行的超过1.6亿次牙科修复治疗中， 涉及树脂粘结复合材料的放置，并承认， 牙医的时间消耗在修改和更换这些牙列，因此显然需要材料。 具有改善的临床性能。相对较短的平均临床寿命（约6年），特别是对于大型 这种治疗方法不仅效率低、成本高，而且每次治疗都会升级为更具侵入性的治疗。的 复合材料的断裂或损失是复合材料失效率的主要原因， 龋齿这些问题都可能与修复体放置过程中的固化不充分有关， 聚合物性质与转化程度相关，而与牙齿的粘附性和相关的 受损牙齿的加固还取决于复合树脂的固化程度。未固化 已知从修复体中浸出的单体促进了在修复体附近的更具侵略性的细菌活性。 修复，这进一步强调了对良好固化的复合材料的需要。值得注意的是， 类似商业复合材料的临床使用寿命存在差异，这表明 材料的可靠放置是高度技术敏感的。我们的目标是设计一种新型的光引发 能够提供自由基的系统，用于超越时空足迹的可靠聚合 一种可见光固化灯。预期临床相关应用是直接放置尺寸 厚的、高度填充的复合修复材料， 遇到的图案。这些重体材料不能容纳在双固化自动混合 注射器该方案的产物可以减轻光固化不完全的复合材料的所有顾虑 通过开发全新的光活化氧化还原聚合引发体系， 一种形式可以通过采用暗固化工艺来增强复合材料的欠固化区域中的初始固化 持续超过暴露于固化光。我们的早期结果表明有限的光聚合 在直接曝光期间仅达到10%的转化，然后可以进展到无色的完全转化。 聚合物在随后的黑暗阶段。或者，另一个版本的启动器预计将产生完整的 在可见光的短暂激活之后，甚至在没有从光接收曝光的区域内， 光固化如果成功，这个示范项目将在光固化方面取得突破， 显著增加固化深度，并完全保证牙科复合材料的完全转化， 树脂水泥光聚合。除了保证完全转换和优化的明显好处外， 此外，还具有其他优点，例如由于聚合物的存在而降低的聚合应力和改善的粘合剂结合。 可以实现在复合基底上的更渐进的聚合过程。如果这里成功了， 这是光聚合技术的一个非常重要的进步，毫无疑问，它将超越牙科。

项目成果

Photo-polymerization kinetics of a dental resin at a high temporal resolution.

高时间分辨率下牙科树脂的光聚合动力学。

• DOI: 10.1016/j.jmbbm.2021.104884
• 发表时间: 2021
• 期刊: Journal of the mechanical behavior of biomedical materials
• 影响因子: 3.9
• 作者: Sullivan,Braden;Kalliecharan,David;Kostylev,Ivan;Earle,Guy;Stansbury,JeffreyW;Price,RichardB;Labrie,Daniel
• 通讯作者: Labrie,Daniel

Visible-Light Photoinitiation of (Meth)acrylate Polymerization with Autonomous Post-conversion.

• DOI: 10.1021/acs.macromol.1c00761
• 发表时间: 2021-09-14
• 期刊: MACROMOLECULES
• 影响因子: 5.5
• 作者: Kim, Kangmin;Sinha, Jasmine;Stansbury, Jeffrey W.;Musgrave, Charles B.
• 通讯作者: Musgrave, Charles B.