Effect of two different volumes of sodium hypochlorite on endodontic treatment outcome following single-visit root canal treatment: A split-mouth, double-blind, randomized controlled trial

Aim: This split-mouth (SM), randomized controlled trial was planned to assess the influence of two different volumes (15 ml and 25 ml) of 2.5% of sodium hypochlorite (NaOCl) on the endodontic treatment outcome of teeth with apical periodontitis (AP) by radiographic and clinical evaluation. Materials and Methods: The study protocol was approved by the ethics committee (25/XX/IEC/2017/11). Using block randomization, permanent lower molars with pulp necrosis and chronic AP (periapical index [PAI] of 3 or above) were allotted to two treatment groups as Group I (low volume [LV]) and Group II (high volume (HV)) wherein 3 ml and 5 ml of NaOCl irrigant were used after each Mtwo rotary file, respectively. This NaOCl was activated by a sonic handpiece. With power at 0.80, P < 0.05, and minimum clinically significant mean intergroup difference set at 0.40 units (standard deviation – 0.88 unit) while using the change in PAI score as the primary outcome, a total of 46 subjects per group were recruited to adequately show a difference in success at the 12-month follow-up. Clinical (at 24 h, 3, 6, 9, and 12 months) and radiographic (6 and 12 months) assessment of all cases was done. Results: Due to SM design of the study, there was no difference in the demographics of subjects between both the groups. Pain scores between both groups were statistically nonsignificant preoperatively (P = 0.857) and at 24 h (P = 0.852). However, there was statistically significant difference in preoperative and 24 h pain scores in Group I (P = 0.000) and Group II (0.000). Comparison of intergroup preoperative and 12-month follow-up PAI scores revealed no statistically significant difference (P = 0.667). However, there was statistically significant difference in preoperative and 12-month follow-up PAI scores in Group I (P = 0.000) and Group II (P = 0.000). Intergroup comparison of PAI scores at baseline (P = 0.894) and follow-up (P = 0.526) revealed no significant difference. Conclusion: Based on the results of the present study, it can be suggested that there is no significant advantage of using HV of NaOCl over LV as far as periapical healing and postendodontic pain are concerned.