The Effect of Using Octenidine Hydrochloride as a Final Irrigation Solution on Teeth With Asymptomatic Apical Periodontitis on Postoperative Pain and Treatment Success: A Prospective Randomized Clinical Study

This single-centre, randomized, parallel-group clinical trial compared two commonly used final irrigants in single-visit root canal treatment: octenidine dihydrochloride (OCT) and chlorhexidine (CHX). Adults with single-rooted, single-canal teeth diagnosed with asymptomatic apical periodontitis were treated in one visit under local anaesthesia and rubber-dam isolation. After shaping with sodium hypochlorite and smear-layer removal with EDTA, the assigned final irrigant was delivered and sonically activated. In both groups, OCT 0.1 percent or CHX 2 percent was activated using three 20-second cycles, and the solution was refreshed with 2 mL between cycles (approximate total 6 mL). Postoperative pain was recorded by participants on an 11-point Numeric Rating Scale (0 = no pain, 10 = worst pain) at 6, 12, 24, and 48 hours. The primary outcome was pain at 48 hours. Secondary outcomes were pain at earlier time points, use of rescue analgesics within 0-48 hours, and unplanned urgent care within 48 hours. The aim was to determine whether OCT reduces early postoperative pain compared with CHX when used as the final irrigant in single-visit endodontics.