Background and Aims: Despite the significant improvement in dentistry, pain after endodontic therapy is still of concern for patients. Non-steroidal anti-inflammatory drugs are the most commonly prescribed oral analgesics used for dental pain relief after root canal treatment. The purpose of this study was to compare the effectiveness of Ibuprofen versus slow-released Diclofenac Sodium in controlling pain following root canal treatment.

Materials and Methods: In this randomized clinical trial, mandibular molars with irreversible pulpitis in 90 patients were selected. The patients were divided into three groups (Ibuprofen, slow-released Diclofenac Sodium and placebo). After examination patients filled in the consent form. Then they received one of the mentioned drugs. After inferior alveolar nerve block, access cavity was prepared and the root canals were prepared using passive step back method. The canals were dried and temporary filling material was placed. Then the pain evaluation form (visual analog scale) was explained and delivered to the patients. Data were analyzed using Repeated Measurement ANOVA, Kruskal-wallis and Man-Whitney U tests.

Results: The mean pain intensity in slow-released Diclofenac Sodium group was 0.87 0.95, 1.17 1.10 for Ibuprofen group, and 2.14  1.70 for placebo group. The differences between groups were statistically significant (P<0.001). The effect of Ibuprofen in controlling post endodontic pain in the first 2 hours was more than slow-released Diclofenac Sodium (P=0.01), but in 10, 18, and 36 hours after treatment, slow-released Diclofenac Sodium was more effective than Ibuprofen (P<0.001).

Conclusion: Premedication with single dose of slow-released Diclofenac Sodium can control post endodontic pain for a longer period of time compared with Ibuprofen.

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