Postoperative pain after foraminal enlargement in teeth with necrosis and apical periodontitis: a prospective and randomized clinical trial

Aim: To evaluate the effect of working length (WL) on postoperative pain in root canal treatment with foraminal cleaning (FC). Methods: One hundred patients with an indication for root canal treatment of teeth diagnosed with pulp necrosis were selected for the study. The teeth were divided into two groups according to the established WL: in group I (n=50), the WL was established at the 0.0 mark on the electronic apex locator (EAL) display. In group II (n=50), the WL was established 1 mm beyond the 0.0 mark on the EAL display. Both groups were treated with the WaveOne Gold reciprocating system (Dentsply Maillefer). Results: Postoperative pain was measured 12, 24 and 48 h using a modified verbal descriptor scale ranging from no pain to maximum pain. In both groups, a significant difference in postoperative pain was observed between all time points analyzed. There was no statistically significant difference in postoperative pain between the two groups. FC performed in single-visit root canal treatment with WL measurement at the 0.0 mark on the EAL display or 1 mm beyond results in a similar intensity of postoperative pain in teeth with pulp necrosis. Conclusion: The working length did not influence endodontic postoperative pain.