Postoperative Pain After Using Reciprocating Motion With Reciproc Files Versus Adaptive Motion With Twisted File Adaptive

Inclusion Criteria: 1. Patients who are medically free from any systemic disease that may contraindicate our interventions. 2. Patient's age between 18-60 years old. 3. Mandibular molars having necrotic pulps with symptomatic or asymptomatic apical periodontitis because this group of patients may have more postoperative pain than vital teeth22. 4. Positive patient's acceptance for participation in the study. Exclusion Criteria: 1. Patients who had used any type of analgesic medication during the preceding 12 hours before the treatment to give true response of pain after instrumentation. 2. Teeth with vital pulps or Symptomatic irreversible pulpitis. 3. Pregnant patients or lactating because of radiographic hazards and use of analgesics27. 4. Any known sensitivity or adverse reactions to ibuprofen.