Action of the XP-endo Shaper System on Oval Root Canals

Objectives:
To evaluate the preparation of long oval root canals of mandibular molars with the XP-endo Shaper system, compared to the Mtwo system, by using micro-computerized tomography (μCT).
Methods: 32 distal roots of mandibular molars were scanned before and after root canal preparation using the SkyScan 1176 X-ray and randomly divided into 2 groups of 16, according to the instrumentation method to be evaluated: XP Group - instrumentation with XP-endo Shaper and Mtwo Group - instrumentation with Mtwo. Data Viewer, CTan and CTVol softwares were used to visualize and analyze three-dimensionally the root canal in the following parameters: the percentage of dentin removed after preparation, root canal volume increase, root canal area increase, untreated canal walls, structure model index (SMI) and volume of hard tissue debris produced. Data were submitted to the Shapiro-Wilk and Mann-Whitney statistical tests (p<0,05).
Results: There were no significant differences between the XP-endo Shaper and Mtwo groups in the volume of dentin removed, increase in canal volume, increase in the surface area of the canal, unprepared surfaces of the canal, volume of debris and SMI.
Conclusions: Neither systems were able to completely prepare the outline of distal long oval canals of mandibular molars. XP-endo shaper and Mtwo systems behaved similarly in all parameters evaluated.