Purpose: The aim of this study was to evaluate the retreatment abilities of the ProTaper Next
(PTN) and F6 SkyTaper (F6) systems by using micro-computed tomography (micro-ct),
radiographic and microscopic imaging techniques.
Materials and Methods: The root canals of twenty-six extracted mandibular premolar teeth
were prepared and obturated. For the retreatment procedure, the teeth were randomly divided
into two equal groups according to endodontic instruments: PTN (X4) and F6 (#40/.06). Preand post-operative filling material volumes were measured with micro-ct, and areas were
measured with radiographic and microscopic imaging techniques. The percentages of residual
material calculated were statistically compared.
Results: There was no statistically significant difference between F6 and PTN for retreatment
efficacy in the micro-ct and radiographic imaging techniques. PTN demonstrated better
cleaning ability when evaluated by microscopic imaging. (p< 0.05). The correlation was
moderate between micro-ct and radiographic, and micro-ct and microscopic imaging groups;
however, it was strong between radiographic and microscopic imaging methods.
Conclusion: The PTN and F6 files had similar effects in the removal of filling material with
micro-ct evaluation. The radiographic imaging method gave similar results with micro-ct