Method: Thirty maxillary incisor teeth with straight and round root canals were decoronated, prepared with ProTaper® Universal (PTU) system, filled using cold lateral condensation of gutta-percha and AHPlus sealer and randomly divided into three groups of 10 teeth each. The root fillings were removed with WaveOne® Reciprocating and ProTaper® Universal Retreatment (PTU-R) systems and hand files. Eucalyptol oil was used as a solvent in all groups. Micro-CT was used to scan the specimens before and after each treatment step. Percentage of volume of residual root filling in the canals were measured. The operating time was recorded. The data were analysed by using the one-way analysis of variance (ANOVA) test and Tukey’s post hoc test.
Result: There was no statistically significant difference between PTU-R and WaveOne® groups. PTU-R and WaveOne® instruments required significantly less time for filling material removal when compared to hand instruments (p<0.05).
Conclusion: None of the instrumentation techniques completely removed all root canal filling material from the root canals. Reciprocating and rotary systems showed similar performances in terms of efficacy and operating time for root filling removal.