不同表面处理对纤维桩粘结强度的影响及电镜观察

目的 比较研究不同表面处理对纤维桩剪切粘结强度的影响及各自的粘结面超微结构。方法 20根纤维桩分为4组（n=5）：表面无处理组（A）、椅旁硅烷化处理组（B）、厂家预处理组（C）、厂家预处理+椅旁硅烷化处理组（D）。分别用树脂核材料置于纤维桩周围制成圆柱形标准试件，包埋，切割成1 mm薄片。每根纤维桩可获得10个薄片。每组5个薄片用于电镜观察纤维桩与树脂核材料粘结界面的超微结构；45个薄片在万能实验机上进行微推出实验，记录数值并进行统计学分析。结果 各组的剪切粘结强度依次为（13.46±1.78）、（18.39±1.60）、（24.54±1.34）、（24.39±1.65） MPa。表面处理组均高于A组，C组高于B组，D组与C组之间无差异。电镜观察各组纤维桩与树脂核材料粘结界面结合良好。C组和D组的纤维桩粘结界面可见微机械固位结构。结论 纤维桩表面由厂家预处理有效提高了纤维桩剪切粘结强度，表面预处理形成的微机械固位和化学粘结固位是增强纤维桩粘结强度的重要因素。

Effect of different silanization treatments on the bond strength of fiber posts with scanning electron microscope

Objective To investigate the influence of different silanization treatments on the shear bond strength of fiber posts and the SEM structure. Methods 20 glass fiber posts were divided into 4 groups （ n = 5 ） ： no treatment （A） , chair-side silane application （B） , industrial silane treatment（C） ,industrial silane treatment followed by chair-side silane application（D）. After surface treatment, a composite resin core was placed around each fiber post by a PTFE tube. The specimens were embedded in a cylinder of clear self-cured acrylic resin and sectioned into l-mm-thick segments with a water-cooled diamond blade. Each post can be sectioned into 10 segments. In each group,5 segments were put under the SEM to observe the ultra microstructure of the bonding interface of the fiber post and the resin core material and 45 other segments were put onto a universal testing machine and micro push-out tests were performed at a cross- head speed of O. 5 mm/min. The data were recorded and analyzed statistically（ α ± 0, 05）. Results The mean shear bond strengths a- chieved in each group were （ 13.46 ± 1.78） 、 （ 18.39 ± 1.60） 、 （24.54± 1.34） 、（24.39 ± 1.65） MPa. The treatment groups showed higher shear bond strengths than that of the control group（A） （ P 〈 0. 001 ）. Group C showed higher bond strengths than Group B（ P 〈 0. 001 ）. No significant difference was found between Group C and Group D. No defects were detectable at the interface of fiber posts and resin core materials in all the groups. In Group C and Group D,microretentive morphological changes were observed. Conclusions Within the limitations of this study,industrial silane treatment can enhance the shear bond strength of fiber posts. SEM analysis re- veals the presence of microretentive morphological changes,which can certainly increase post-retentive properties.