Effects of Two Nickel-Titanium Instrument Systems, Mtwo versus ProTaper Universal, on Root Canal Geometry Assessed by Micro–Computed Tomography

IntroductionThe aim of this study was to compare the effects of Mtwo and ProTaper Universal (PTU) on root canal geometry three-dimensionally by using micro–computed tomography.MethodsA total of 20 canals were prepared with Mtwo or PTU system. Micro–computed tomography scanner was used to scan the specimens before and after instrumentation. Three-dimensional images were reconstructed. The parameters evaluated included canal surface area, volume, structure model index, thickness, straightening, canal transportation, and uninstrumented surface area.ResultsPreparation significantly changed canal surface area, volume, structure model index, thickness, and canal curvature. There were no significant differences between instrument types concerning these parameters and uninstrumented surface area. The canals prepared with PTU showed larger values of transportation compared with those in Mtwo group at the apical third.ConclusionsBoth of the instrumentation systems produced canal preparations with adequate geometry. PTU produced larger transportation at apical third.