Background: Endodontic treatment is fairly predictable in nature with reported success rates up to 86–98%.The removal of gutta-percha using rotary instruments in the retreatment process have decreased the chair-side clinical time. Hence; under the light of above mentioned data, the present study was undertaken for comparing the removal efficiency of root canal fillings and residue using Mtwo retreatment file in adjunct with H-file and self-adjusting file in warm vertical compaction obturated teeth. Materials & methods: A total of 20 extracted non-carious mandibular first premolars were included in the present study. 20 extracted single rooted mandibular first premolars having straight canal with fully formed apices were obtained and access cavity was prepared. Estimation of working length was done. The root canals were prepared with NiTi endodontic rotary instruments Protaper Universal. The teeth were obturated with warm vertical compaction. The quality and apical extent of the root fillings confirmed radio graphically. The teeth were divided randomly into Group 1 and Group 2 with 10 specimens each (n=10). Group 1 included specimens retreated with MTwo file initially followed by finishing with H-file; while Group 2 included specimens retreated with MTwo file initially, followed by finishing with Self adjusting file. After the removal procedure, each root was scanned. The percentage volume of the remaining filling material in the canal walls was calculated. All the results were recorded in Microsoft excel sheet and were analysed by SPSS software. Results: Mean volume percentage of remaining filling materials present in dentin walls after retreatment among group 1 and group 2 specimens was found to be 8.19 mm3 and 5.31 mm3 respectively. Conclusion: Both the instrumentation techniques left filling residue inside the root canals. However; efficacy of Self adjusting files was significantly higher than that of H files in retreatment cases.
Key words: Obturation, Retreatment