Effects of Post Space Preparation on the Apical Seal of Root Canal Fillings.

Objective: To investigate the leakage of residual canal fillings after post space preparation using a glucose fluid transport model.Methods: Seventy extracted single-rooted anterior teeth were collected.The canals were prepared with the step-back technique and obturated with gutta-percha and AHplus using the lateral condensation.The teeth were randomly divided into 4 experimental groups and 2 control groups.The lengths of residual fillings in experimental groups were 3mm,5mm,7mm and 10mm respectively.A modified glucose fluid transport model was used to test the glucose leakage after 1,2,3 and 4 weeks.Results: The leakage was not significantly different among four test groups in the first week(P0.05).From the second week,group1 showed more leakage than group 3 and 4(P0.05),and the difference between group1 and group 2 was not significant(P0.05).Conclusion: Under the conditions of this study,the longer residual canal filling was better to decrease microleakage.