IMPROVED AMINO ACID-MODIFIED DENTAL GLASS IONOMERS

患者对耐用、美观、防龋齿牙科材料的需求 只需要最少的牙齿准备就可以放置，这导致了 对玻璃离聚体感兴趣。玻璃离聚体聚合度低 收缩，具有与牙齿相似的热膨胀系数 结构，并可通过与牙齿的化学粘合将微渗漏降至最低 结构和金属。持续的氟化物释放允许特定部位 龋齿控制。不幸的是，目前可用的玻璃离子 配方拉伸强度差，弹性模数低。 弹性和溶解性。其中一个问题在于聚丙烯酸酯 玻璃离聚体的酸结构。羧酸基团存在于 直接附着到聚合物主干上会产生非常坚硬的 结构。由于空间位阻，一些羧基变成 无法访问，阻止它们参与与Ca++的交联 来自玻璃填充物的Al++和来自牙齿结构的Ca++。这个 这项建议的目标是开发一种离聚体配方，通过 氨基酸类单体与羧酸的结合 离聚合物主链不同距离的基团，以允许 更大的灵活性、更少的刚性离子簇、更好的填料分散性 以及与牙齿结构的物理化学粘合。这一概念和 技术已在聚合物化学文献中得到证实，并被 由我们的初步数据支持，其中拉伸显著增加 并发现了这种柔性聚合物的弯曲强度。这个 将对单体和聚合物的配方进行分析和表征。 最佳单体比例和聚合物的相对分子质量将 决心最大限度地提高其物理性能。选定的机械设备 性能(径向拉伸强度、压缩强度、弯曲强度 将测试新聚合物的强度、耐磨性)；酸 溶解度、与牙釉质和牙本质的结合强度及显微结构 将对改进后的离聚体进行测试和检查。可持续发展的微观机制 离聚体失效仍不清楚。实现消除贫困的目标 控制裂缝扩展的微观结构中的薄弱环节 并通过碱改性改善其物理性能 聚合物结构是增强材料进一步发展的关键 可见光固化离聚体系统。

Patient demand for durable, esthetic, anti-cariogenic dental materials that requires minimal tooth preparation for placement has led to renewed interest in glass ionomers. Glass ionomer has low polymerization shrinkage, has coefficient of thermal expansion similar to that of tooth structures and can minimize microleakage by chemical adhesion to tooth structures and metal. Sustained fluoride release allows site-specific caries control. Unfortunately, the presently available glass ionomer formulation suffers from having poor tensile strength, low modulus of elasticity and solubility. One of the problems lies in the polyacrylic acid structure of the glass ionomer. The carboxylic acid groups reside in direct attachment to the polymer backbone resulting in a very rigid structure. Due to steric hindrance, some carboxyl groups become inaccessible, preventing their participation in cross-linking with Ca+ + and Al+ + + from glass fillers and Ca+ + from tooth structures. The objective of this proposal is to develop an ionomer formulation through the incorporation of amino acid derived monomers with carboxylic acid groups at various distances away from the polymer backbone, to allow for greater flexibility, less rigid ionic cluster, better filler dispersion and physicochemicaI adhesion to tooth structures. This concept and technique have been substantiated in polymer chemistry literature and were supported by our preliminary data where significant increases in tensile and flexural strengths in such flexible polymers were found. The formulation of monomers and polymers will be analyzed and characterized. The optimal monomer ratios and the molecular weights of the polymers will be determined to maximize their physical properties. Selected mechanical properties (diametral tensile strength, compressive strength, flexural strength, abrasion resistance) of the new polymer will be tested; acid solubility, bond strength to enamel and dentin, and the microstructures of the improved ionomers will be tested and examined. The micromechanisms for ionomer failure remains unclear. Accomplishing the goals for eliminating the weak links in the microstructures that governs fracture propagation and for improving the physical properties through modification of basic polymer structures are crucial to the further development of reinforced visible light cured ionomer systems.