Immediate clinical and microbiological evaluation of the effectiveness of 0.5% versus 3% sodium hypochlorite in root canal treatment: A quasi‐randomized controlled trial

Aim To test the hypothesis that in the daily routine of a specialist clinic in endodontics that irrigation during root canal preparation with 3.0% NaOCl will result in fewer postoperative samples with cultivable bacteria than irrigation with 0.5% buffered NaOCl but, at the same time, will not result in a higher frequency of postoperative pain nor swelling. Methodology Two hundred ninety‐eight patients were enrolled in the study and were randomly assigned into two groups – 0.5% NaOCl and 3% NaOCl. All endodontic diagnoses were included. Root canal treatment was performed, and bacterial sampling was carried out prior to root filling. The patients were requested to complete a form regarding pain and swelling seven days postoperatively. Fisher’s exact test, Mann–Whitney U‐test, Mantel–Haenszel chi‐squared and the chi‐squared test with a significance level of P