Im/Miscible Adhesive/Dentin Interface:Structure/Mechanic

牙胶/混溶粘合剂/牙本质界面：结构/力学

• 批准号: 6683709
• 负责人: Paulette Spencer
• 金额: $ 27.88万
• 依托单位: UNIVERSITY OF MISSOURI KANSAS CITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-15 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6683709
• 关键词: adhesions; biomaterial compatibility; biomaterial development /preparation; collagen; composite resins; dental adhesive /sealant; dentin; human subject; patient oriented research; physical property; polymethacrylate; restorative dentistry; water environment; water solubility

DESCRIPTION: If composite resins are to be considered a viable alternative to Dental amalgam, the durability of the dentin/adhesive (d/a) bond must be improved. Under in vivo conditions, this bond can be the first defense against substances that penetrate and ultimately undermine the composite restoration. The durability of the d/a bond is directly related to the quality of the HL but measuring quality has been a formidable problem. To date, the majority of our techniques have provided an indirect assessment, e.g., testing methods that measure fracture resistance of bulk d/a specimens pre- and post-water immersion are not sensitive enough to identify interfacial defects where aqueous degradation begins. Our recent in situ characterization of the molecular structure and micro-mechanics of the hybrid layer has indicated a serious limitation-physical separation of the BisGMA/HEMA adhesive upon mixing with water in the demineralized dentin. The critical dimethacrylate (BisGMA), the component contributing most to the cross-linked polymeric adhesive, infiltrated a fraction of the wet, demineralized dentin. The overall hypothesis of this work is that in the presence of moist clinically relevant dentin surfaces, methacrylate-based adhesives formulated to include water-compatible components will provide decreased phase separation and thus, enhanced structural integrity and increased durability of the hybrid layer as compared to state-of-the-art commercial adhesives. The Specific Aims will test the hypotheses: 1) cationic surfactants, water compatible photoinitiators and water-compatible cross-linking dimethacrylate co-monomers in methacrylate-based adhesive formulations will decrease phase separation that occurs in water and act synergistically to reduce the detrimental effects associated with such phase separation; 2) these adhesives formulated with water-compatible components will provide enhanced dentin infiltration and be miscible with wet demineralized matrices of healthy and caries-affected dentin, assuming suitable viscosity; 3) the module of elasticity at the interface of healthy dentin and caries-affected dentin with methacrylate-based adhesives exhibiting reduced phase separation and water compatible characteristics will be stable upon exposure to aqueous environments and that the interfacial elastic moduli will not lead to stress concentration that will result in failure initiation at the interface during loading; 4) that methacrylate-based adhesives exhibiting reduced phase separation, enhanced infiltration, improved miscibility and structural integrity in the presence of wet demineralized healthy dentin matrices will provide strong, durable d/a bonds as compared to state-of-the-art commercial adhesives.

描述：如果复合树脂被认为是牙科银汞合金的可行替代品，牙本质/粘结剂(d/a)粘结的耐久性必须得到改善。在活体条件下，这种结合可以第一次防御渗透并最终破坏复合修复的物质。D/a键的耐久性直接关系到HL的质量，但测量质量一直是一个令人敬畏的问题。到目前为止，我们的大多数技术都提供了间接评估，例如，测量大量d/a试件在浸水前和浸水后的抗裂性的测试方法不够敏感，无法识别开始水降解的界面缺陷。我们最近对杂化层的分子结构和微观力学的原位表征表明，在脱矿的牙本质中，双GMA/HEMA粘结剂在与水混合时存在严重的物理分离。关键的二甲基丙烯酸酯(双GMA)，对交联型聚合物粘合剂的贡献最大的成分，渗透到湿的脱矿牙本质的一部分。这项工作的总体假设是，与最先进的商业粘结剂相比，在潮湿的临床相关牙本质表面存在的情况下，包含水相容成分的甲基丙烯酸酯粘结剂将减少相分离，从而增强混合层的结构完整性和耐用性。具体目标将检验以下假设：1)甲基丙烯酸酯基胶粘剂配方中的阳离子表面活性剂、水相光引发剂和水相交联二甲基丙烯酸酯共单体将减少在水中发生的相分离，并协同作用以减少与这种相分离相关的有害影响；2)这些含水相组分的粘合剂将提供增强的牙本质渗透，并与健康和受龋齿影响的牙本质的湿性脱矿基质相容，假设粘度合适；3)健康牙本质和患龋牙本质与具有减少相分离和水相容特性的甲基丙烯酸酯基粘接剂界面的弹性模数在暴露于水环境中时将是稳定的，并且界面弹性模数不会导致应力集中而导致加载时在界面处引发失效；4)与最先进的商用粘结剂相比，在湿式脱矿化健康牙本质基质的存在下，具有减少相分离、增强渗透性、改善相容性和结构完整性的甲基丙烯酸酯基粘接剂将提供坚固耐用的d/a粘结。