Abstract
BACKGROUND: The risk of pain and flare up following root canal treatment of asymptomatic necrotic teeth remains an unsolved issue despite the recent advances in canal preparation and obturation procedures. The present study evaluated the role of two final irrigations in minimizing such risk. Aim: To compare the effect of final irrigation with antimicrobial - corticosteroid mixture with that of cryotherapy on post-instrumentation pain and microbial reduction in patients with single canalled teeth with necrotic pulps and asymptomatic apical periodontitis. MATERIAL AND METHODS: Twenty-eight patients with asymptomatic necrotic single-canalled teeth participated in the study. After diagnosis, access cavity preparation and chemico-mechanical preparation with rotary files and 2.5% NaOCl irrigation, patients were randomly allocated to receive a final irrigation of either a mixture of levofloxacin, dexamethasone and fluconazole or intracanal cryotherapy. Patients recorded their postoperative pain on an 11-point numerical rating scale up to 72 hours. Microbial samples were collected at 3 stages: preoperatively, post-instrumentation and post- final irrigation. RESULTS: The two groups showed no significant increase in postoperative pain intensity at all time intervals compared to the preoperative pain intensity. The two groups showed mild pain intensity at 6 and 12 hours postoperatively with no significant difference between them. No pain was reported in both groups at 24, 48 and 72 hours postoperatively. The post-final irrigation samples showed significant bacterial and candidal load reduction in both groups. CONCLUSIONS: Final irrigation with antimicrobial-corticosteroid mixture and cryotherapy following 2.5% NaOCl prevented the rise of the postoperative pain intensity and minimized the intracanal microbial loads with no significant differences between both irrigations.