One of the main problems of traditional endodontic filling materials is the difficulty in achieving complete removal of filling material. The removal of as much material as possible from inadequately prepared and/ or filled root canal system is necessary to uncover remaining necrotic tissues or bacteria that might be responsible for periapical inflammation and post-treatment disease. Obturation material removal can be achieved by several methods. Methods: A total of 60 extracted single- rooted mandibular premolars with fully formed apices were collected and cleaning and shaping was done. Samples were later obturated using 3 different sealers (Endofill, iRoot SP and MTA Fillapex). Cone beam evaluation for all teeth was performed. Retreatment for all teeth was done using 2 different retreatment systems (Ultrasonic and ProTaper Universal retreatment system (PTUS)). Cone beam post retreatment scan was done and analyzed against the previous post obturation cone beam images and the comparisons were recorded. Results: PTUS showed higher efficiency in removal then the ultrasonic. MTA Fillapex showed the highest mean percent of removed filling material, followed by Endofill then iRoot SP. Conclusions: Filling debris were found in all cleaved canals after endodontic retreatment with both ultrasonic and ProTaper Universal retreatment system. MTA Fillapex sealer showed the highest percent of removed filling material, and the Endofill sealer showed less percent of removed filling material, and the iRoot SP sealer showed the least percent of removed filling materials but with statistically significantly higher percentage scores recorded with the PTUS. The mean time spent by ultrasonic was statistically significantly higher than with the PTUS.