Effect of Preoperative Diclofenac Potassium on Postoperative Endodontic Pain

Inclusion Criteria: * Patients with active pain (moderate-to-severe) in mandibular molars. * Patients with prolonged response to cold testing and electric pulp tester. * Patient with the ability to understand and use pain scales. * Patient with vital coronal pulp tissue on access. * Patient who accept to enroll to the study. Exclusion Criteria: * Patients' allergies or any other contraindication to diclofenac potassium or articaine. * Pregnant and lactating females. * Patients having pain medication in the last 6 hours. * Patient has more than one symptomatic mandibular tooth in the same quadrant. * Patients with periradicular pathosis and/or radiolucency other than widened periodontal ligaments. * Patients with active peptic ulcer and gastrointestinal disorders. * Patients with history of bleeding problems or anticoagulant use within the last month.