Comparison of centring ability and transportation between four nickel titanium instrumentation techniques by micro‐computed tomography

Aim To compare the centring ability and transportation of ProTaper Next (PTN), ProTaper Universal (PTU), Race 123 and RevoS using micro‐computed tomography (μCT). Methodology Sixty mesial root canals of thirty mandibular molars were divided virtually into coronal, middle and apical thirds, and two reproducible reference points were marked on the external surface of the roots creating 360 measurement points. Samples were randomly allocated to four NiTi instrumentation techniques. Group 1: PTU up to F2 (n = 16), group 2: PTN up to X2 (n = 18), group 3: Race 123 up to T2 (n = 12) and group 4: RevoS up to SU (n = 14). To reproduce a clinical situation, samples were prepared on a phantom head using a surgical operating microscope. Samples were scanned pre‐ and postoperatively using μCT to compare and calculate the transportation and centring ratio. The data were analysed using parametric statistics. Results In the coronal and middle third of the root canals, there were significant differences in centring between PTN and PTU (coronal P