Efficacy of chlorhexidine as a final irrigant in one‐visit root canal treatment: a prospective comparative study

Aim To evaluate postoperative pain and radiographic evidence of periapical healing in teeth with apical periodontitis treated in one visit with an additional final irrigation using 2% chlorhexidine (CHX) and to compare the results with conventional two‐visit root canal treatment (RCT) with an intracanal calcium hydroxide (CH) dressing as a control group. Methodology Ninety asymptomatic maxillary anterior teeth with periapical lesions were treated by a single operator. Root canals were prepared using the step‐back technique with manual instrumentation with 2.5% NaOCl and 5% EDTA as irrigants. Half of the teeth were randomly assigned to the one‐visit (OV) group and received an additional final rinse with 2% CHX before canal filling. The other teeth were treated in two visits (TV) with a CH paste made by mixing CH powder and distilled water as an interappointment dressing. All patients were recalled and investigated clinically and radiographically for 24 months. Postoperative pain at 24–48 h and changes in apical bone density indicating radiographic healing were evaluated statistically using the Mann–Whitney U‐test followed by the Friedman and the Wilcoxon tests (α = 0.05). Results There were no significant differences between two groups regarding the incidence of postoperative pain at 24 h (OV group 50% no pain, 47.6% mild, 2.4% moderate pain/TV group 55% no pain, 42.5% mild, 2.5% moderate pain) and at 48 h (OV group 95% no pain, 5% mild pain/TV group 98% no pain, 2% mild pain). None of the patients reported severe postoperative pain, swelling and/or flare‐ups during the follow‐up period. There was no significant difference in the radiographic healing rates (OV group 97.6% PAI 1 and/or PAI 2 and 2.4% PAI 3/TV group 95% PAI 1 and/or PAI 2 and 5% PAI 3; P > 0.05). Conclusion Both groups provided favourable and similar postoperative pain and periapical healing rates at 24 months. Thus, one‐visit RCT with a final rinse with 2% CHX is an acceptable alternative to two‐visit RCT with CH as temporary dressing in maxillary anterior teeth.