试桩对玻璃纤维桩粘接强度的影响

目的：通过体外试验评价试桩对纤维桩粘接强度的影响。方法：选择32颗因正畸需要而拔除的单根管前磨牙，完善根管治疗后行纤维桩桩道预备，随机分为4组，每组8颗，分别采用以下处理方法粘接纤维桩，A组：不试桩，直接粘接；B组：试桩＋99．9％乙醇清洁；C组：试桩＋99．9％乙醇清洁＋硅烷化；D组：试桩＋酸蚀＋99．9％乙醇清洁＋硅烷化。纤维桩粘接后，制备lmm厚的薄片标本，在万能试验机上采用微推出试验（push-outtest），计算粘接强度，体视显微镜观察粘接界面破坏方式。结果：除D组在冠部和根部的粘接强度与A组的差异无统计学意义（P〉0．05）外，余各组各部位间的粘接强度差异均具有统计学意义（p〈0．05），试桩会造成纤维桩与树脂间粘接界面破坏的比例升高。结论：试桩会降低纤维桩的粘接强度，试桩后采用过氧化氢酸蚀，99．9％乙醇清洁再行硅烷化处理可提高纤维桩的粘接强度，降低试桩对粘接强度的不利影响。

Effects of try-in on shear bond strength of glass fiber post

Objective： To evaluate the influence of try-in in shear bond strength of fiber post in vitro. Methods： A total of 32 premolars with single root canal and similar shape and size were selected. The teeth were randomly divided into 4 groups after endodontic treatment, with 8 samples in each group. Fiber posts were cemented using the following methods. Group A： No try-in, cemented directly. Group B： try-in, followed by anhydrous alcohol cleaning. Group C： try-in, followed by an- hydrous alcoholcleaning and silanization. Group D： try-in, followed by etching, anhydrous alcohol cleaning and silaniza- tion. After cementation, the roots were cut into 1.0ram-thick sections, followed by push-out test which were performed with a universal testing machine. The data were recorded and analyzed. Fracture modes of interface were observed using stere- omicroscope. Results： There were significant differences among 4 groups in different parts except group D and A at root canal coronal and apical. The bonding interface t~acture between fiber posts and cements increased after try-in. Conclusion： The shear bond strength of fiber posts reduced after try-in. It showed that using hydrogen peroxide,anhydrous alcohol and silanization after try-in could improve the shear bond strength to fiber posts and reduce the disadvantage effect to shear bond strength.