ABRASION RESISTANT NANOSTRUCTURED DENTAL COMPOSITES

该项目的总体目标是开发新的耐磨性， 用作直接和间接用途的纳米结构复合材料 放置修复材料。为达到这一目标，应采取以下措施 已经提出了具体目标： 方案的具体目标1提出了加工和表征 利用各种组合的几种独特的复合结构 无机和有机聚合物。几种先前报道的溶胶-凝胶 已经提出了加工技术作为生产新产品的方法 单相和双相硅酸盐、铝酸盐和磷酸盐 胶体填充物颗粒。根据我们的初步数据，我们 纳米结构耐磨牙科复合材料的假设 可能是由这些独特的粒子和 可聚合单体。这一相当简单但独特的组合 由一系列聚合反应产生的材料可以 导致无机物和有机物质的亲密结合。这个 填料颗粒本身由微孔无机交联物组成 可浸渍可聚合的链状网络结构 甲基丙烯酸酯单体。这些材料的原位聚合 形成纳米级互穿的无机/有机复合体。这个 硅酸盐/甲基丙烯酸酯的组合将成为 将评估最佳的粒子参数(大小、形状、密度)。 这种熟悉的组成组件组合放在一个 独特的微结构方式被认为具有最大的潜力 立即申请。新组份无机和有机相 已经提出了一些组合，这些组合提供了改善 结构的化学稳定性和/或生物兼容性。 该计划的具体目标2旨在评估 这些独特的非结构复合材料的临床性能。 评价的最初和主要重点将集中在 耐磨性评定。拟议的体外试验利用 消减二体微磨损或循环表面微应力 评估磨损的技术。将使用现有的牙科复合树脂 作为阴性对照，人牙釉质作为阳性对照。整体而言 加工的退化涉及耐磨性，因为它与 无机和有机聚合物组分的化学稳定性将 也要接受评估。性能明显好于 目前的牙科复合材料在至少一种测试条件下很可能 使复合材料表现出更好的临床性能和 将进行进一步评估。其他非常重要的性质 它将在最有希望的材料上进行测试，包括蠕变， 断裂韧性和强度、弹性模数、硬度和疲劳。 建议的工作顺序旨在系统地评估 复合材料的成分和微观结构与力学性能的关系 复合材料的耐磨能力。已完成的 拟议的工作有望导致新磨损的开发 耐腐蚀的牙科复合材料。

The overall objective of this project is to develop new wear resistant, nanostructured composite materials for use as direct and indirect placement restorative materials. To achieve this objective the following specific aims have been proposed: Specific Aim 1 of the program proposes to process and characterize several unique composite structures utilizing various combinations of inorganic and organic polymers. Several previously reported sol-gel processing techniques have been proposed as methods of producing novel monophasic and diphasic silicate, aluminate and phosphate nenoporous and colloidal filler particles. Based on our preliminary data, we hypothesize that nanostructured wear resistant dental composite materials could result from the combination of these unique particles with polymerizable monomers. This rather simple but unique combination of materials which result from a series of polymerization reactions, can lead to an intimate combination of inorganic and organic substances. The filler particles themselves consist of a microporous inorganic cross linked network structure which can be impregnated with polymerizable methacrylate monomers. The in situ polymerization of these materials result in nano scale interpenetrating inorganic/organic complex. The silicate/methacrylate combination will serve as the model by which the optimal particle parameters (size, shape, density) will be evaluated. This familiar compositional component combination put together in a unique microstructural manner is felt to have the greatest potential for immediate application. New component inorganic and organic phase combinations have been proposed which offer the potential to improve the chemical stability and or biocompatibility of the structure. Specific Aim 2 of this program is designed to assess the potential clinical performance of these unique nonostructured composite materials. The initial and principal focus of the evaluation will center on the assessment of wear resistance. The proposed in vitro tests utilize wither a two body microabrasion or a cyclic surface microstressing technique to assess wear. Current dental composite resins will be used as negative controls and human enamel as a positive control. The overall degradation processed involved in wear resistance as it relates to the chemical stability of the inorganic and organic polymer components will also be assessed. Materials which perform significantly better that current dental composites under at least one test condition are likely to result in composites which exhibit improved clinical performance and will be further evaluated. Other properties of significant importance which will be examined on the most promising materials include creep, fracture toughness and strength, elastic modulus, hardness, and fatigue. The sequence of work proposed is designed to systematically evaluate the relationship between the composite composition and microstructure and the ability of composite materials to resist wear. Completion of the proposed work is expected to lead to the development of new wear resistant dental composite materials.