含固位性填料和普通填料光固化复合树脂动态黏弹性及临床操作性能的对比

摘要

BACKGRoUND:The clinical manipulation properties of light-cured composite resin,such as flowing property.filling capacity,shaping and stability has not unified definition in dental materials notwithstanding more studies of rheological behaviors were undertook.OBJECTIVE:To explore the dynamic viscoelasticity difference of unpolymerized light.cured composite resins with retentive filler or normal filler,and to investigate effect on the clinical manipulation properties of rheological behaviors in two light-cured composite resins to define an ideal resin.DESIGN,TIME AND SETTING:This controlled study is a correlation study of integrating the base study and clinical use.Basic study was performed in January 2003 at Key Laboratory of Engineering Plastics of Chinese Academy of Sciences in Beijing.The clinical observation study was conducted at the Stomatology Center,Haikou People's Hospital until December 2006.MATERIALS:Light-cured composites employed in this study were reinforced with RF(experimental composite resin I,ECR-Ⅰ)or NF(experimental composite resin Ⅱ,ECR-Ⅱ),which were supplied by Dental Materials Laboratory.Medical College of Stomatology of Peking University.They contained different types of fillers,but had the same resin matrix and volume percent of filler.METHODS:The dynamic viscoelastic properties of ECR-Ⅰ or ECR-Ⅱ were measured respectively with the dynamic stress rheometer DSR-200 in a room maintained 25℃.Flowing property,filling capacity,shaping and stability property were employed to assess the clinical manipulation property of ECR.MAIN OUTCOME MEASURES:Viscoelasticity(G',G",tan δ)and clinical manipulation of two kinds of compound resins.RESULTS:The dynamic viscoelastic behavior of the two composites was sensitive to changes in frequency.ECR-Ⅰhad significantly higher G'than ECR-Ⅱ.ECR-Ⅰ had a greater ability of stability and shaping.and a lower potential for deformation clinically.ECR-Ⅱ had significantly higher G"than ECR-Ⅰ.and ECR-Ⅱ had a higher flowing ability clinically.ECR-Ⅱ had significantly higher tan δ than ECR-Ⅰ.ECR-Ⅱ was found to be more viscous and better filling capacity,with a good adaptation to the cavity of the tooth clinically.CONCLUSION:The dynamic viscoelasticity(G',G",tan δ)and clinical manipulation properties of ECR-ⅠI or ECR-Ⅱ are compared.The ideal composites should have higher G'and lower tan δ%背景:尽管对光固化树脂的流变行为已有较多研究,但对光固化树脂临床操作性能的评价指标,即流动性、充填性、成形性和稳定性,目前口腔材料界还没有统一的定义.目的:评价含固位性填料(retentive filler,RF填料)和普通填料(normal filler,NF填料)的未聚合光崮化复合树脂的动态黏弹性,并探讨两种光固化复合树脂动态黏弹性对临床操作性能的影响,以确定理想的光固化复合树脂应具备的条件.设计、时间及地点:结合材料学基础实验和临床应用的对比观察.基础实验部分先期于2003-01在北京中国科学院(化学研究所)工程塑料国家重点实验室完成;临床观察部分在海南省海口市人民医院口腔医学中心完成,时间一直持续到2006-12.材料:光固化复合树脂包括含RF填料的实验性复合树脂Ⅰ(experimental composite resin Ⅰ,ECR-Ⅰ)和含普通钡玻璃填料的实验性复合树脂Ⅱ(experimental compositeresin Ⅱ.ECR-Ⅱ),两者填料含量的百分比(体积)相同,并含有相同的树脂基质和光固化体系,由北京大学口腔医学院口腔材料研究室配制.方法:在室温25℃条件下,采用平行板动态应力流变仪DSR-200,分别测试用RF填料强化的未聚合光固化复合树脂ECR-Ⅰ和用NF填料强化的未聚合光固化复合树脂ECR-Ⅱ的动态黏弹性.采用流动性、充填性、成形性和稳定性4个指标评估两种树脂的临床操作性能.主要观察指标:两种复合树脂的黏弹性质(G',G",tall δ)和临床操作性能.结果:两种树脂的动态黏弹性对剪切率比较敏感,ECR-Ⅰ的贮能模量(G')明显高于ECR-Ⅱ,临床显示ECR-Ⅰ有更好的稳定性和成形性,潜在变形小.ECR-Ⅱ的损耗模量(G")明显高于ECR-Ⅰ,临床显示ECR-Ⅱ流动性更好.ECR-Ⅰ损耗角(tan δ)明显低于ECR-Ⅱ,临床显示ECR-Ⅱ更多黏性行为,充填性更好,容易和牙齿上的洞壁贴合.结论:对照两种复合树脂的黏弹性质(G',G",tan δ)和临床操作性能,理想的光固化复合树脂应有较高的贮能模量(G')和较低的损耗角(tan δ).