According to the inclusion criteria the patients enrolled in the study and allocated randomly into two groups either Wave One (group A) or Neolix ( group B) the endodontic treatment is done at single visit. firstly the patient's medical and dental history is taken .the patient assign on informed consent. and then,anaesthetized and access cavity performed and root canal preparation is done by either two systems and then irrigation and obturation is done. the patient record the post operative pain in sheet with NRS after 6,12,24,48hr and the operator will recall the patient to check the records and follow up the patient.