Influence of brushing motions on the shaping of oval canals by rotary and reciprocating instruments

Objective The effects of brushing on shaping with three different instruments were assessed in oval canals. Design Mandibular incisors were assigned to 6 groups ( n = 12/group) according to the system, each one with or without brushing: Reciproc Blue, VDW.Rotate, and Race EVO. Micro-computed tomography was performed before and after preparation. Results Brushing strokes caused no increase in canal volume, surface area, and structure model index independently of the system ( p > 0.05), except for RaCe EVO in the full canal surface area ( p < 0.05). Brushing did not increase the prepared areas ( p > 0.05), except for Reciproc in the apical canal ( p < 0.05). Reciproc with no brushing exhibited less pericervical dentin than with brushing ( p < 0.05), while RaCe EVO with brushing resulted in less remaining dentin ( p < 0.05). Conclusions The brushing motion had no effects on the overall shaping performance of the 3 instruments tested. An exception was the increase in prepared surface area in the apical canal segment when the Reciproc instrument was used with brushing strokes.