Inclusion Criteria:  - Medically free patients. Mandibular permanent molar teeth: Diagnosed clinically with pulp necrosis. Absence of spontaneous pain. Slight widening in the periodontal membrane space or with periapical radiolucency Patient's age ranges between 22 to 45 years with no sex predilection. Patients who can understand Modified Visual Analogue Scale (VAS). Patients' acceptance to participate in the trial. Patients able to sign informed consent.  Exclusion Criteria:  - Medically compromised patients: Pain levels and healing following treatment would be compromised as these patients have shown higher incidence of pain and lower healing rate. Pregnant women: Avoid radiation exposure, anesthesia, and medication. If analgesics or antibiotics have been administrated by the patient during the past 24 hours preoperatively might alter their pain perception. Patients reporting bruxism or clenching: Avoid further pressure on an already inflamed tooth inducing subsequent irritation and inflammation. Teeth that show association with acute periapical abscess and swelling: Need special treatment steps which could involve additional visits with incision and drainage. Also, it could influence initiation and progression of postoperative pain. Greater than grade I mobility or pocket depth greater than 5mm. Need special surgical and/or periodontal therapy. No restorability: Hopeless tooth. Vital teeth. Immature teeth. Radiographic evidence of external or internal root resorption vertical root fracture, perforation, calcification.