Effectiveness of Root Canal Irrigation and Dressing for the Treatment of Asymptomatic Apical Periodontitis: A Systematic Review Assessing Complementary Timeframes.

Sodium hypochlorite (NaOCl), ethylenediaminetetraacetic acid (EDTA), and calcium hydroxide (Ca(OH)) are used in root canal treatment. However, further research is needed to assess their effectiveness at time points not considered in previous guidelines. This review complements the systematic review by Rossi-Fedele and Rödig (2023) by considering time points excluded by the latter. A search was conducted in PubMed-MEDLINE, Scopus, EMBASE, Google Scholar, and repositories between March and May 2024. Four studies met the inclusion criteria, providing data from 212 teeth for irrigation and 108 for dressings. No significant differences in pain reduction within 7 days or radiographic reduction of apical lesion size were found between 2% chlorhexidine, 5.25% NaOCl, EDTA, and various NaOCl concentrations. Single and multiple visit protocols also showed no significant differences in postoperative pain. Two studies had a 'low risk' of bias and two 'some concerns'. Evidence suggests that Ca(OH) dressings may not offer additional benefits.