Comparison of activated versus nonactivated irrigation on bacterial load reduction and postoperative pain: A randomized controlled trial

Background: For effective disinfection of the root canal system, irrigant activation enhances antimicrobial efficacy and reduces postoperative pain. Aim: To compare activated and nonactivated irrigation techniques in reducing bacterial load and postoperative pain in single-rooted teeth with pulpal necrosis. Materials and Methods: Fifty-four patients aged 18–55 years, single-rooted necrotic teeth were randomly allocated into three groups ( n = 18) based upon different irrigation techniques: Group A–side-vented needle, Group B–passive ultrasonic, and Group C–air-sonic. The irrigation protocol followed for all groups was 2.5%sodium hypochlorite, 17% ethylenediaminetetraacetic acid, and 2% chlorhexidine. Before collection of the sample, 0.3% L-lecithin and 3% Tween-80 were used as irrigant neutralizers. Sampling: (S1) before access opening, (S2) after access opening, before cleaning and shaping, (S3) after cleaning and shaping. Sample collection by sterile paper points and inoculated onto agar plates; the colony-forming units (CFU) were quantified using a colony counter. Postoperative pain was recorded by patient marking on the provided VAS chart at baseline, 6, 12, 24, and 48 h. Data analyzation by one-way analysis of variance, Chi-square test, and Bonferroni post hoc analysis. Results: At S1, the mean CFU score was 0.00 in all groups; at S2, 1.00 across all groups. After irrigation (S3), mean CFU scores were 0.53 in Group A, 0.12 in Group B, and 0.31 in Group C, with a statistically significant difference ( P = 0.041). Postoperative mean pain scores at 6, 12, and 24 h were 2.944, 2.111, and 0.778 in Group A; 2.500, 1.556, and 0.278, in Group B; and 2.889, 1.867, and 0.433 in Group C. Statistically significant differences were observed at 12, 24, and 48 h ( P = 0.001). Conclusion: Passive ultrasonic irrigation was the most effective technique due to superior irrigant activation at higher acoustic streaming and cavitation, assuring biofilm disruption, reducing bacterial load, and reducing postoperative pain score.