Im/Miscible Adhesive/Dentin Interface: Structure/Mechanic

摘要 在美国每年进行的2.9亿次牙科修复中，有2亿次是失败的替补 修复术。这种对替代疗法的重视预计将随着公众对以下问题的关注而增长 汞和牙科汞齐迫使牙医选择替代材料，例如复合材料。从中等到大型 复合修复体有更高的失败率，更多的复发龋齿和更频繁的 替补。中到大型II类复合修复体的临床寿命可以缩短 对我们的患者尤其有害，因为移除这些修复体可能会导致广泛的缺失 牙齿结构良好，需要更大、更复杂的修复体，最终需要整体修复 牙齿掉了。在活体条件下，粘结剂/牙本质(a/d)结合可能是对物质的第一防御。 这会穿透并破坏复合修复。我们最近对分子的原位表征 A/d界面的结构和微观力学特性表明，a/d界面存在严重的物理分离。 在脱矿的牙本质中与水混合时粘合。关键的二甲基丙烯酸酯(双GMA)， 对交联胶贡献最大的成分，渗透了一部分湿的、脱矿的 牙本质。在这份修订后的竞争续期申请中，我们建议根据我们的结果开发一种水- 通过解决A/D键的下一个化学“阿喀琉斯之跟”，即 甲基丙烯酸酯基质。总体假设是，在潮湿的临床相关牙本质存在的情况下 基材，配制成耐水性和耐酯酶的甲基丙烯酸酯类粘合剂 提供增强的界面结构完整性和更高的耐用性。我们的目标是阐明 在临床相关条件下，化学变化会导致牙本质的可预见变化。 粘合材料的性能(结构、界面行为、机械性能和耐久性)和 基于动力学、生物相容性和界面模拟的原位a/d键形成特征优化 损坏。其具体目标是：1)设计和合成最有前途的耐酯酶、耐水- 基于迭代组合优化/合成方法的相容甲基丙烯酸酯基胶粘剂；2) 目的：评价和测试耐酯酶、耐水性、耐水性的胶粘剂的物化性能、力学性能和结构性能。 在与无龋齿等临床相关基质的界面处具有相容的甲基丙烯酸酯基粘接剂 并影响牙本质；3)评价牙本质与耐酯酶、耐水的牙本质之间的结合强度。 相容的甲基丙烯酸酯基胶粘剂使分子间的特定和可量化的关系 可以建立结构和牙本质粘结。项目叙事 在美国每年进行的2.9亿次牙齿修复中，有2亿次是为了 失败的修复1，这种对替代疗法的重视预计将成为公众的关切 关于牙科汞合金的汞释放迫使牙医选择替代材料，例如复合材料 树脂。在活体条件下，粘结剂/牙本质粘结剂可能是对以下物质的第一种防御 渗透和破坏复合修复体。如果我们成功地完成了 这一项目对患者的直接好处将是：1)大幅减少 降解释放未反应成分的粘合系统以及2)粘合系统的发展，所述粘合系统 与潮湿的口腔环境兼容，因此更能抵抗过早降解 破坏复合修复体。

Abstract Out of 290 million dental restorations placed/year in the U.S., 200 million are replacements for failed restorations. This emphasis on replacement therapy is expected to grow as the public's concern regarding mercury and dental amalgam forces dentists to select alternative materials, e.g. composite. Moderate to large composite restorations have higher failure rates, more recurrent caries and increased frequency of replacement. The reduced clinical lifetime of moderate to large class II composite restorations can be particularly detrimental for our patients because removal of these restorations can lead to extensive loss of sound tooth structure with the concomitant need for enlarged, more complex restorations and eventually total tooth loss. Under in vivo conditions the adhesive/dentin (a/d) bond can be the first defense against substances that penetrate and undermine the composite restoration. Our recent in situ characterization of the molecular structure and micro-mechanics of the a/d interface indicated a serious limitation, i.e. physical separation of adhesive upon mixing with water in the demineralized dentin. The critical dimethacrylate (BisGMA), the component contributing the most to the crosslinked adhesive, infiltrated a fraction of the wet, demineralized dentin. In this revised competitive renewal application, we propose to build upon our results to develop a water- compatible adhesive by addressing the next chemical "Achilles heel" of the a/d bond, i.e. ester linkages in the methacrylate matrix. The overall hypothesis is that in the presence of moist clinically relevant dentin substrates, methacrylate-based adhesives formulated to be water-compatible and esterase-resistant will provide enhanced interfacial structural integrity and increased durability. Our goal is to elucidate how alterations in the chemistry will lead, under clinically relevant conditions, to predictable changes in dentin adhesive material properties (structure, interfacial behavior, mechanical properties and durability) and to optimize features for in situ a/d bond formation based on kinetics, biocompatibility and modeling of interfacial damage. The specific aims are: 1) to design and synthesize the most promising esterase-resistant, water- compatible methacrylate-based adhesives using an iterative combinatorial optimization/synthesis approach; 2) to evaluate and test the physicochemical, mechanical and structural properties of the esterase-resistant, water- compatible methacrylate-based adhesives at the interface with such clinically relevant substrates as caries-free and -affected dentin; 3) to evaluate the bond strengths between dentin and esterase-resistant, water- compatible methacrylate-based adhesives so that specific and quantifiable relationships between molecular structure and dentin bonding can be established. Project narrative Out of 290 million dental restorations placed annually in the United States, 200 million are replacements for failed restorations 1 and this emphasis on replacement therapy is expected to grow as the public's concern about mercury release from dental amalgam forces dentists to select alternative materials, e.g. composite resin. Under in vivo conditions the adhesive/dentin bond can be the first defense against substances that penetrate and undermine the composite restoration. If we are successful at completing the goals outlined in this project the direct benefits to the patient will be: 1) a substantial reduction in those components of the adhesive system that degrade releasing unreacted components and 2) development of adhesive systems that are compatible with the wet oral environment and thus, more resistant to premature degradation which undermines composite restorations.