Effect of Cyperus Articulatus on Bacterial Reduction and Postoperative Pain

Inclusion Criteria: * Healthy adult Patient. * Medically free patients. * Mandibular permanent premolar teeth: * Diagnosed clinically with necrotic pulp. * Absence of pain. * Radiographic evidence of chronic apical periodontitis . * Radiographic evidence of single root with single canals. * Normal occlusal contact with opposing teeth. * Patients' acceptance to participate in the trial. Exclusion Criteria: * Medically compromised patients having significant systemic disorders (ASA III or IV). * If analgesics or antibiotics have been administrated by the patient during the past 24 hours preoperatively as it might alter their pain perception. * Pregnant women: to avoid radiation exposure, anaesthesia, medication and hormonal fluctuation that might increase pain prevalence. * Patients reporting bruxism, clenching, TMJ problems or traumatic occlusion: to avoid further pressure on inflamed tooth which induce subsequent irritation and inflammation. * Patients with two or more adjacent teeth requiring endodontic treatment. * Teeth that requires further procedural steps or multidisciplinary approach, which is out of this experiment's scope: i. Association with swelling or fistulous tract. ii. Acute periapical abscess. iii. Mobility Grade II or III. iv. Pocket depth more than 5mm. v. Previous root canal treatment. vi. Non-restorable. vii. Immature root. viii. Radiographic evidence of external or internal root resorption, vertical root fracture, perforation, calcification. * Inability to perceive the given instructions.