ABSTRACT
AIM: To assess the effect of Neem versus 2.5% NaOCl as root canal irrigants on the intensity of post-operative pain and amount of endotoxins following root canal treatment of mandibular molars with necrotic pulps. METHODOLOGY: This parallel, prospective, double-blinded, randomized controlled trial with allocation ratio 1:1 was conducted in the out-patient clinic of the Endodontic Department, Faculty of Dentistry, Cairo University, Egypt. Fifty healthy patients with mandibular molars with necrotic pulps were randomly assigned into two equal groups using computer software. In the intervention group, root canals were irrigated using Neem; whilst 2.5% NaOCl was used in the control group. A standard root canal treatment was performed in two visits using ProTaper Next rotary files, with no intracanal medication. Pain intensity was assessed using a numerical rating scale (NRS) 6, 12, 24 and 48 h following instrumentation and canal filling. Endotoxin samples were collected using three paper points before and after canal instrumentation and a sandwich ELISA method was used to quantify the level of endotoxins. Demographic, baseline, and outcome data were collected and analysed using chi-square tests (for the comparisons of categorical variables), Mann-Whitney tests (for non-normally distributed variables) and Student's t tests (for normally distributed variables), A P-value < 0.05 was considered to be statistically significant. RESULTS: The mean pain scores within the two groups decreased continually over time. The mean pain scores in the Neem group were lower than those in the 2.5% NaOCl group at 6, 12, 24 and 48 h following instrumentation and canal filling with no significant difference between them except at 24 h following instrumentation (P = 0.012). Both irrigants significantly reduced endotoxin levels compared to the pre-instrumentation samples (P < 0.001) by 8% for the NaOCL group and 18% for the Neem group. CONCLUSION: Neem and 2.5% NaOCl were not significantly different in terms of reducing the intensity of post-operative pain during all follow-up periods except at 24 h following instrumentation where Neem was associated with lower pain intensity. Both irrigants significantly reduced endotoxin levels but were not effective in eliminating endotoxins completely from root canals of mandibular molars with necrotic pulps.