Does maintaining apical patency reduce early postoperative pain after root canal treatment? A randomized controlled trial in asymptomatic vital single-rooted teeth

The aim of this randomized controlled clinical trial was to evaluate the effects of implementing apical patency (AP) on early postoperative pain in asymptomatic vital single-rooted teeth. Seventy-two patients with asymptomatic, vital, single-rooted teeth were randomly assigned to either the patency group or the non-patency group. In the patency group, a #10 K-file was gently extended 1 mm beyond the working length at each instrument change to maintain AP, whereas in the non-patency group, instrumentation was confined within the working length. All treatments were completed at one visit by a single operator using the One Curve NiTi rotary system (25/0.06 or 35/0.04; MicroMega, Besançon, France) and standardized irrigation (2.5% NaOCl, 17% EDTA). Pain was recorded on a Numerical Rating Scale (NRS) at 0–6, 6–12, 12–24, 24–36, and 36–48 h. The data were analyzed using Mann–Whitney U, χ²/Fisher, Friedman, and Generalized Estimating Equations (GEE) tests (α = 0.05). The groups did not differ significantly in age, gender, or jaw location (p > .05). The pain scores were similar at all time intervals (p > .05) and decreased significantly over time in both groups (p < .001). From 12 to 24 h onward, most patients reported minimal or no pain. Analgesic intake within 48 h was infrequent and comparable between groups (p > .05). In asymptomatic vital single-rooted teeth, maintaining AP did not significantly affect postoperative pain within the first 48 h after single-visit root canal treatment. Therefore, routine use of AP solely to reduce early postoperative pain is not warranted in this patient group. For asymptomatic vital single-rooted teeth, AP should not be performed with the expectation of reducing early postoperative pain; its use should be considered based on case-specific clinical considerations rather than pain control alone.