Methods: Seventy eight extracted premolar teeth were prepared and filled with RealSeal™ using either cold lateral compaction or warm vertical compaction techniques (39 roots each). Each group was subgrouped into 3 groups. Re-treatment was done with one of the following: Hedström files (control group), R-Endo® and ProTaper® re-treatment files (13 roots each). Tooth-Clearing technique was conducted and the percentage of the remaining material in each third of the canal was calculated using image analyzer software and the mean of the residues was statistically analyzed.
Results: For cold laterally compacted RealSeal™ there was no significant difference in mean percentage of remnants in the coronal, middle and apical third of the root canal between used files (P>0.05). However, for the warm vertically compacted the two rotary re-treatment files left significantly less remnants than Hedström files in the middle third of the root canal (P<0.05) but no significant difference in remnants in the coronal and apical thirds. The two rotary re-treatment system indicated the mean percentage of remnants was significantly more in the apical third than the middle and coronal thirds (P<0.05). However for the Hedström files the remnants was significantly higher in middle and apical thirds (P<0.05) than coronal third with no significant difference between the middle and apical thirds (P >0.05)
Conclusion: with the limitation of this study, none of the used system was able to completely remove of laterally and vertically compacted RealSeal™ from the root canal.