硬化性牙本质粘结界面形态观察和粘结强度的研究

摘要

Objective Aim of study is to compare the characteristic of the hybrid layer with total - etching adhesive agent on sound dentine and sclerotic dentine. The bonding interface were observed with transmission electron microscope (TEM) and bond strength were determined with Microtensile Tester . Methods 20 molars with sclerotic dentine were extracted for periodontal disease, as experimental group. 20 premolars with normal dentine were extracted for orthodontic , as control group. All specimens were treated with 3M Single Bond total — etching adhesive system and composite resin . The micro-structures of dentine bonding interface were observed with TEM and determined bond strength with Microtensile Tester . U— sing SPSS11. 5 software, obtained data were submitted to Independent -Samples T Test. Results TEM showed that the hybrid layer of bonding composite resin were clear in sound dentine and sclerotic dentine , but the sclerotic dentine were a little thinner. Microtensile Tester of the bond strength values (M Pa)were as follows; control group(40.55 ±4.34) ; experimental group ( 38.43 ± 2.28 ). Independent - Samples T Test revealed that control group was significant higher than experi -mental group (P <0.05 ). Conclusion There were differences at the thickness of hybrid layer microstructure while using 3M Single Bond total - etching adhesive agent between sound or sclerotic dentine , the latter was a little thinner. On the experimental condition, Microtensile Tester showed that the bond strength of sclerotic dentine was lower than sound dentine .%目的本文通过研究经全酸蚀牙本质粘结系统分别处理正常牙本质和硬化性牙本质后,应用透射电子显微镜(transmission electron microscope,TEM)来观察获得的混合层超微结构特点,并利用微拉伸测试方法对其粘结强度进行测试,为临床操作提供依据.方法 选择因牙周病而拔除的磨牙20颗,牙 合面具有典型硬化性牙本质,作为实验组;另选择因正畸减数而拔除前磨牙20颗,根尖孔已形成,作为对照组.实验组和对照组的牙全部应用3M Single Bond全酸蚀粘结系统处理牙本质后与复合树脂进行粘结,TEM下观察粘结界面的微观形态;在微拉伸测力仪上进行粘结强度测试.所得实验数据用SPSS11.5软件做两个独立样本t检验进行分析.结果 经全酸蚀粘结系统对正常牙本质和硬化性牙本质与复合树脂进行粘结处理后TEM下均可见清晰的混合层,与对照组相比,实验组的混合层较薄;微拉伸粘结强度值(MPa)结果为对照组(40.55±4.34),实验组(38.43±2.28),不同牙本质类型对粘结强度的影响差异有显著性意义(P<0.05).结论 3M Single Bond全酸蚀系统处理正常牙本质与硬化性牙本质后与复合树脂粘结均可形成清晰混合层,硬化性牙本质的混合层较薄;在本实验条件下,与正常牙本质相比,硬化性牙本质与复合树脂的微拉伸粘结强度较低.