Evaluation of root canal filling material removal from root canals filled with various obturation techniques

Objective: the aim of the study was to compare the time required for re-treating single cone obtrutation, cold vertical compaction and warm vertical compaction and to measure remaining root canal filling material. material-method: root canals of 54 mandibular incisors were instrumented up to size f2 with the protaper universal instrument and randomly divided into 3 experimental groups: cold lateral compaction, corresponding single cones and warm vertical compaction (continuous wave). root canals were filled using mta fillapex. re-treatment was performed using protaper universal retreatment files. the teeth were then sectioned horizontally at 2, 4, 6, and 8 mm from the apex. the sections were inspected under a stereomicroscope and the residual gutta-percha occupied areas were converted to percentages of the total area. root canals cleanliness was scored according to a five-stage scale. the time required for re-treatment were recorded. the data for the time were analysed statistically using one-way anova and tukey posthoc tests and the data for canal cleanliness were analysed using kruskal-wallis. the testing was performed at 95% confidence level (p < 0.05). results: there was no significant difference between the groups with respect to canal cleanliness. the time required for re-treatment for the warm vertical compaction group was significantly longer than those observed in the other groups (p < 0.05). no significant difference was observed between cold lateral compaction and single cone obturation with respect to time (p > 0.05). discussion: warm vertical compaction was removed in longer time from root canals of mandibular incisors than either cold lateral compaction or single cone obturation.