Effect of Propolis nanoparticles versus sodium hypochlorite as root canal irrigant on postoperative pain and bacterial reduction in mandibular premolars with necrotic pulps: a randomized clinical trial

Aim: The aim of this study was to clinically compare the intensity of post-operative pain and the amount of bacterial load reduction after using 20mg/ml propolis nanoparticles extract solution as root canal irrigant versus 2.5% NaOCl during chemo-mechanical preparation in asymptomatic necrotic mandibular premolars treated in a single visit.Methodology: This is a double blinded, parallel, prospective randomized controlled trial, with allocation ratio 1:1. Fifty patients having single canalled necrotic mandibular premolar were included. Intervention group received 20 mg/ml propolis nanoparticles solution as irrigant, while control group used 2.5% NaOCl. Single visit endodontic treatment was done using EdgeEndo files. Postoperative pain was measured at 6, 12, 24, and 48 hours using Numerical Rating Scale. Culturing was used to assess intracanal bacterial levels before and after preparation. Also, the number of analgesic tablets were counted. All demographic, baseline and outcome data were statistically analyzed. A P-value < 0.05 was considered statistically significant.Results: Postoperative pain in both groups was similar regarding incidence and intensity (P>0.05). No significant difference in the incidence or the number of analgesic tablets taken by the patients was detected in both groups (P>0.05). Both irrigants significantly reduced the intracanal bacterial load however, propolis nanoparticles solution showed superior efficacy against anaerobes (P = 0.027). Conclusion: Propolis nanoparticles solution was similar to NaOCl regarding incidence and intensity of postoperative pain but showed higher anaerobic bacterial reduction when treating asymptomatic necrotic mandibular premolars in a single visit.