IMPROVED AMINO ACID-MODIFIED DENTAL GLASS IONOMERS

患者对耐用、美观、防龋牙科材料的需求 需要最少的牙齿准备放置导致更新 对玻璃离子感兴趣。 玻璃离子聚合度低 收缩，热膨胀系数与牙齿相似 结构，并可以通过化学粘附到牙齿上来减少微渗漏 结构和金属。持续的氟化物释放允许特定部位 龋齿防治 不幸的是，目前可用的玻璃离聚物 制剂具有差的拉伸强度、低的弹性模量、 弹性和溶解性。其中一个问题在于聚丙烯酸酯 玻璃离聚物的酸结构。羧酸基团存在于 直接连接到聚合物主链上， 结构由于空间位阻，一些羧基变成 难以接近，阻止它们参与与Ca+ +的交联 Al+来自玻璃填料，Ca+ +来自牙齿结构。 的 该建议的目的是开发一种离聚物配方， 氨基酸衍生单体与羧酸的结合 基团在离聚合物主链的各种距离处，以允许 更大的柔性，更少的刚性离子簇，更好的填料分散 和对牙齿结构的物理化学粘附。 这一概念和 这些技术已经在聚合物化学文献中得到证实， 我们的初步数据支持， 和弯曲强度。 将分析和表征单体和聚合物的配方。 最佳的单体配比和聚合物的分子量将 决心最大限度地提高其物理性能。选定的机械 性能（径向拉伸强度、压缩强度、弯曲强度 强度，耐磨性）的新聚合物将进行测试;酸 溶解性、与牙釉质和牙本质的粘结强度以及 将对改进的离聚物进行测试和检查。微观机制， 离聚物失效仍不清楚。实现消除贫穷的目标 微观结构中控制断裂扩展的薄弱环节 并通过改性碱性聚乙烯来改善其物理性能 聚合物结构对于进一步发展增强的 可见光固化离聚物体系。

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.