Abstract:Objective To compare the difference of the microleakage repaired by different repair methods for root canals in premolars. Methods 30 premolars with single canal at the similar size were collected. After finished the root filling, all teeth were randomly divided into A group, B group and C group. Each group of 10 specimens was embedded in the plaster models. The post and core was repaired by direct method in A group, semiindirect method in B group and indirect method in C group. After water invasion for 6 months, 30 pieces were dyed by 2% methylene blue for 24h and sectioned. The degree of microleakage was recorded and analyzed in three groups. Results The leakage in g A group was more significantly serious than that in C group (P<0.05), but no significantly difference between A group and B group, B group and group C(P>0.05). Conclusion The level of microleakage in premolars, which is restored by fiber post core with the indirect method, is significantly better than that with the direct method. The indirect method has a good edge seal action and is more suitable for clinical application.