关键词: 循环加载, 纤维桩, 微渗漏

Abstract:

Objective The purpose of this study was to evaluate the microleakage between endodontically treated teeth canal dentin and three cements under cyclic mechanical loading. Methods A total of 30 extracted human mandibulars were randomly divided into 3 groups .Three cements （3M ESPE RelyXTM Luting，Super-bond C＆B， 3M ESPE RelyXTM Unicem ）were used respectively to bond fiber posts of 1.4 mm in diameter after the root canal was prepared with usual methods. The cores were made with the same resin. All the teeth were mounted in resin blocks. Loads were applied on the samples at 135 degrees and tested with fatigue test machine， which were immersed in a 0.5% basic fuchsin solution. After 20 000 cycling the specimens were cut into two sections longitudinally， and then observed with stereomicroscope， and Kruskal-Waillis H test was used to analyze the results. Results After thermocycling， the microleakage was observed in all the three cements for bonding tooth canal dentin but was significantly different among them （ P < 0.05 ）. Conclusion There is microleakage between endodontically treated teeth canal dentin and the three cements under cyclic mechanical loading. Super-bond C & B shows the least microleakage compared with the other two.

Key words: cyclic mechanical loading, fiber posts, microleakage