REDUCTION OF POLYMERIZATION SHRINKAGE AND STRESS

减少聚合收缩和应力

• 批准号: 5210167
• 负责人: SABINE H DICKENS
• 金额: --
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/5210167
• 关键词: biomaterial development /preparation; biomaterial evaluation; chemical property; composite resins; polymerization; tensile strength

The long-term goal of the proposed research is to develop methods to measure and counteract the stresses developed in resin-based materials due to polymerization shrinkage. The specific aims are: (i) to build a tensometer for measuring stresses developed during the polymerization of resin-based materials; (ii) to investigate the potential relaxation of polymerization stresses in resins and composites. An apparatus for measuring shrinkage stresses will be built following a design by Feilzer et al., (1993). Slow and fast curing composite systems with increasing amounts of fillers, will be used to test a possible correlation between stress and shrinkage and to evaluate instrument reproducibility. Stoichiometric amounts of compounds will be added to composites to compensate for curing contraction. If these amounts will not reduce stress to zero, compound concentrations will be increased to further reduce stress. The limiting amounts will be determined from the effects of the reactant concentrations on other physical properties of the composite (e.g., degree of cure, diametral tensile strength, 4-point transverse test (TS), adhesion to dentin, water sorption and solubility). To maintain high physical properties, a decrease in TS of more than 15% would be considered unacceptable. Systems identified in Specific Aims as candidate systems for reducing polymerization-induced shrinkage and stress in dental composites will be compared in a final randomized side- by-side experimental design including controls. Although stress reduction will be the primary response variable of interest, shrinkage, degree of cure, DTS, transverse strength, water sorption and solubility will all be considered in the final recommendation of a useful system.

拟议研究的长期目标是开发方法来 测量和抵消树脂基材料中产生的应力 由于聚合收缩。具体目标是：(一)建设 用于测量聚合过程中的应力的张力计 树脂基材料；(Ii)研究材料的潜在松弛 树脂和复合材料中的聚合应力。 一台测量收缩应力的仪器将在以下情况下建造 由Feilzer等人设计，(1993)。慢速和快速固化复合材料体系 随着填充物数量的增加，将用于测试可能的 应力与收缩的相关性及评价工具 再现性。化学计量比的化合物将被添加到 可补偿固化收缩的复合材料。如果这些金额将 不把压力降到零，化合物浓度就会增加到 进一步减轻压力。限制金额将由 反应物浓度对聚四氟乙烯其他物理性质的影响 复合材料(例如，固化度、径向拉伸强度、4点 横向试验(TS)、与牙本质的粘附力、吸水性和溶解性)。 为了保持高物理性能，TS降低了15%以上 会被认为是不可接受的。在特定目标中确定的系统 作为减少聚合引起的收缩和 牙科复合材料的应力将在最终的随机侧进行比较- 包括对照的旁侧实验设计。虽然压力很大 减少将是感兴趣的主要反应变量，收缩， 固化度、DTS、横向强度、吸水率和溶解度 所有这些都将在一个有用的系统的最终建议中得到考虑。