Different final irrigation protocols on postoperative pain and swelling following single-visit non-surgical root canal treatment in necrotic mandibular first molars: a randomized controlled trial
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Published on: July 26, 2022
Mina Zarei1, Maryam Javidi1, Rouzbeh Farrokhi2
1Department of Endodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Islamic Republic of Iran.
Introduction:
Postoperative flare-ups remain a frequent complication after root canal treatment, particularly in teeth with necrotic pulps. This randomized clinical trial evaluated postoperative pain, swelling, and analgesic intake following single-visit endodontic treatment of necrotic mandibular molars using three irrigation approaches: conventional needle irrigation (CNI), side-vented needle irrigation (SNI) and passive ultrasonic irrigation (PUI).
Methods:
In this single-blind, parallel-group randomized clinical trial, 45 patients diagnosed with necrotic mandibular first molars were equally assigned to CNI, SNI, or PUI groups (n = 15 each). All procedures were completed in one visit using standardized rotary instrumentation with 5.25% sodium hypochlorite as the primary irrigant. Pain intensity was recorded using a 0-10 visual analogue scale at 6, 24, 48, and 72 h after treatment, while postoperative swelling was documented as present or absent. Analgesic intake was also registered. Data analysis was performed using Kruskal-Wallis, Fisher's exact, and Cochran's Q tests with a significance level set at 0.05.
Results:
Pain intensity in the CNI group was significantly higher at 24, 48, and 72 h compared with both SNI and PUI groups (p ≤ 0.008). At 24 h, swelling occurred more frequently in the CNI group (46.7%) than in the SNI (0%) and PUI (6.7%) groups (p = 0.002). Patterns of analgesic consumption were consistent with pain outcomes. No statistically significant differences were identified between the SNI and PUI protocols.
Conclusions:
Within the limitations of this randomized clinical trial, both SNI and PUI were associated with reduced postoperative pain, swelling, and analgesic use compared with conventional needle irrigation in necrotic mandibular molars. These findings suggest that improved irrigant delivery methods may contribute to minimizing postoperative flare-ups.
Trial Registration:
Iranian Registry of Clinical Trials (IRCT20100110003036N2), registered 1399.05.08.
