Evaluation of the Effect of Root Canal Shaping With TruNatomy on Postoperative Pain and Operative Torque Generated During Instrumentation

Inclusion Criteria: * Patients who are free from any physical or mental handicapping condition and no contributory systemic disease. * Age between 30-60 years old. * Males \& Females. * Patients' acceptance for participating in the trial through an informed consent * Maxillary permanent premolar teeth: * Diagnosed clinically and radiographically with pulp necrosis * With or without periapical radiolucency * Negative response of pulp tissue to thermal and electric pulp tester * Possessing two independent roots each having a type I canal * Patent canals with no internal calcification or resorptive lesions * Fully formed roots * Root curvatures less than 30 Exclusion Criteria: * Patient with contributory medical condition * Badly destructed teeth * Patients with pre-operative pain * Patients having significant systemic disorders * Patients with two or more adjacent teeth requiring root canal therapy * Patients who had received antibiotics in the last month * Teeth presenting with: * Positive response to thermal or electric pulp tester * History of trauma or previous endodontic treatment * Immature or open apices * Association with acute periapical abscess and swelling or fistulous tract * Fused roots at any level * Canals larger than size 15# K-file * Periodontonal/ endodontic lesions * Mobility higher than grade I * Radiographic evidence of external or internal root resorption vertical root fracture, perforation, calcification. * Severe root curvature (\>30)