Effects of Irrigation Activation and Obturation Techniques on Pain After Root Canal Treatment

This prospective, parallel-group randomized controlled clinical trial was conducted at the Department of Endodontics, Faculty of Dentistry, Biruni University, Istanbul, Türkiye. The study included 72 patients aged 18-65 years diagnosed with symptomatic irreversible pulpitis in permanent single rooted teeth with a single root canal and closed apices. Ethical approval was obtained from the Biruni University Ethics Committee (2015-KAEK-80-23-41), and written informed consent was obtained from all participants.

An a priori sample size calculation was performed using G*Power 3.1, assuming an effect size of 0.79, a significance level of 0.05, and 80% statistical power. The minimum required sample size was 14 participants per group. To account for potential dropout, 18 participants were enrolled in each of the four groups.

Participants were randomly allocated to four parallel groups using a computer-generated randomization sequence prepared by an individual not involved in the study. Group assignments were concealed in sealed opaque envelopes until treatment. Participants were not informed of the specific treatment technique assigned to them.

All root canal treatments were performed in a single appointment by one experienced endodontist. Following local anesthesia and rubber dam isolation, working length was determined using an electronic apex locator and confirmed radiographically. Root canals were prepared using the XP-endo Rise Glider and XP-endo Rise Shaper systems. The instrumentation protocol was standardized across all groups.

Group 1 received conventional needle final irrigation with 2.5% sodium hypochlorite and 17% EDTA, followed by cold lateral condensation using gutta-percha and AH Plus sealer.

Group 2 received sonic activation of 2.5% sodium hypochlorite and 17% EDTA using the EDDY system, followed by cold lateral condensation using gutta-percha and AH Plus sealer.

Group 3 received conventional needle final irrigation followed by thermoplasticized gutta-percha obturation using the Fast-Pack and Fast-Fill systems with AH Plus sealer.

Group 4 received EDDY sonic irrigation activation followed by thermoplasticized gutta-percha obturation using the Fast-Pack and Fast-Fill systems with AH Plus sealer.

Following obturation, the quality of the root canal filling was assessed radiographically, and definitive coronal restorations were completed using composite resin.

Postoperative pain intensity was assessed using an 11-point Numerical Rating Scale ranging from 0 (no pain) to 10 (worst pain) before treatment and at 8 hours, 24 hours, 48 hours, and 7 days after treatment. Participants recorded pain scores and analgesic consumption on standardized forms. Ibuprofen 600 mg every 8 hours was recommended when needed for pain relief; paracetamol 500 mg was recommended when ibuprofen was unsuitable. Completed assessment forms were collected at the one-week follow-up visit.

The primary outcome was postoperative pain intensity. Analgesic consumption was additionally evaluated. Statistical analyses were performed using nonparametric methods, with statistical significance set at p < 0.05.