RESUMO
AIM: To evaluate canal transportation and centring ability of ProTaper Next (PTN) and Twisted File Adaptive (TFA) systems using microcomputed tomographic (micro-CT) imaging. METHODOLOGY: Twenty isthmus-containing mesial roots of mandibular molars were anatomically matched based on similar morphological dimensions using micro-CT evaluation (resolution of 14.25 µm) and assigned to two experimental groups (n = 10) according to the system used for root canal preparation: PTN and TFA groups. Then, the specimens were scanned again and the matched images of the mesial canals, before and after preparation, were examined at three cross-section levels (3, 5 and 7 mm from the apical end of the root) to analyse canal transportation and centring ratio. Independent-samples t-test was used to compare canal transportation and centring ratio between the groups. All statistical procedures were performed with a significance level set at 5%. RESULTS: Root canals prepared with either PTN or TFA systems had similar canal transportation and centring ratios at all levels (P > 0.05). CONCLUSION: PTN and TFA had similar results regarding canal transportation and centring ability.