The retreatment abilities of ProTaper Next and F6 Skytaper: a micro-computed tomography study.

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 (microct), 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). Pre- and 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 were calculated, and then statistically compared. The significance level was set at p<0.05.

Results: There was no statistically significant difference between F6 and PTN for retreatment efficacy in the micro-ct and radiographic imaging techniques (p>0.05). 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 microct evaluation. The radiographic imaging method gave similar results with micro-ct imaging.