用微拉伸法测试三种牙本质粘结剂在离体后牙纵裂模式中的强度

Evaluation of the Microtensile Bond Strengths of Three Adhesive Systems on Vertically Fractured Molars

目的:比较三种牙本质粘结剂在离休纵裂后牙粘结中用微拉伸法所测得的牙本质粘结剂强度。方法:选用36颗拔除的人类磨牙,随机分为3组,制备成纵折模型,舌侧牙片剖面开本质粘结树脂块,3组粘结系统分别为可乐丽、单瓶粘结剂、超强粘结剂。标本置37℃水中恒温24h后,舌侧半树脂块修整成约1.5mm厚酒杯状薄片,粘在特制的固定装置上,在万能材料试验机上以1mm/min的横梁移动速率做拉伸测试。用扫描电镜观察其断裂方式。结果:用微拉伸法所测得的三种粘结剂强度分别为:可乐丽:19.9±0.95Mpa;单瓶粘结剂:12.8±0.81Mpa;超强粘结剂:15 3±1.2MPa,经方差分析,三种粘结剂强度问均有显著差别(P<0.05)。扫描电镜观察见试件断裂均为界面破坏。结论:用微拉伸法测得的可乐丽粘结强度相对较高。

Objective: To determine the bond strengths between dentin and three adhesive systems on vertically fractured molars, by means of microtensile tests. Methods: Thirty - six extracted human molars were randomly assigned to three groups. Teeth were cut parallel to their long axis. A block composite resin was built on the longitudinal section with one of the following adhesive systems: Clearfil SE Bond and Single Bond,Super Bond C&B. All specimens were stored in 37℃ C distilled water for 24 hours.The block composite resin were trimmed into slabs of 1.5mm thick.then tested by the universal testing machine at a cross speed of 1mm/min.The fracture surfaces were examined by SEM. The results were compared using ANOVA. Results: The mean bond strength for each resin was as follows: Clearfil SE Bond, 19.9 ± 0.95Mpa; SingleBond, 12.8±0.81Mpa; Su-per Bond C&B, 15. 3±1. 2Mpa. There were significant differences among three adhesive systems(P<0. 05). All specimens were found fractured at interface.Conclusion: The microtensile bond strength of Clearfil SE Bond was the highest.