Evaluation of postoperative pain following the use of nano-calcium hydroxide as an intracanal medicament in root canal treatment: A randomized controlled trial

Calcium hydroxide (Ca(OH)₂) is widely used due to its antimicrobial and anti-inflammatory properties; however, its limited penetration into the complex root canal anatomy may reduce its effectiveness. Nano-calcium hydroxide (NCH), with its smaller particle size, offers better diffusion and potentially improved therapeutic outcomes. The aim of this study was to evaluate and compare the levels of postoperative pain following the use of Ca(OH)₂ and NCH as intracanal medicaments in root canal treatment. This randomized controlled trial included 90 patients with necrotic, single-rooted teeth and periapical lesions. The patients were randomly assigned into two groups: Ca(OH)₂ was applied in Group 1, and NCH was applied in Group 2 as intracanal medicaments. After root canal preparation and medicament application, postoperative pain levels were assessed using a 10-cm Visual Analog Scale (VAS) at 6, 12, 24, 48, and 72 hours. Inclusion criteria were individuals aged 18–65 years without systemic conditions affecting pain perception. Exclusion criteria included recent use of antibiotics or analgesics, pregnancy, and systemic diseases requiring antibiotic prophylaxis. Pain scores were compared to evaluate the effectiveness of nano-CH in reducing postoperative pain. Statistical analyses were performed using the Independent t-test, Chi-square test, Mann-Whitney U test, and Friedman test (α=0.05). No statistically significant difference was found between the two groups regarding postoperative pain (p>0.05). In intra-group evaluation, the lowest increase in pain was observed at 6–12 hours in the NCH group (p=0.019), and at 24–48 hours in the Ca(OH)₂ group (p=0.02). There was also no statistically significant difference in analgesic intake between the groups (p=0.094). In conclusion, both NCH and Ca(OH)₂ provide similar levels of postoperative pain reduction. However, the earlier reduction in pain observed in the NCH group (6–12 hours vs. 24–48 hours), although not statistically significant, may offer clinical benefits.