Root surface strain during canal shaping and its influence on apical microcrack development: a preliminary investigation

Aim To determine the root surface strain ( RSS ) generated during root canal shaping and its effects on apical microcrack development. Methodology Twenty‐five extracted human mandibular premolars were selected and decoronated. The teeth were instrumented with either the ProTaper ( PT ) or WaveOne ( WO ) (Dentsply Maillefer) NiTi rotary systems ( n = 10 per group) or used as controls ( n = 5). Instrumented root canals were enlarged to ProTaper F4...