Inclusion Criteria:  Age 18-40 years. No significant present and past medical findings. Mature, single rooted teeth with single canal and closed apices. Symptomatic irreversible pulpitis with symptomatic apical periodontitis (moderate to severe pain according to VAS). Periodontal status- healthy periodontium according to Classification of Periodontal Disease and Conditions. (i.e. code 0).  Exclusion Criteria:  Immature teeth with open apices. Root presenting with resorption, fracture, root caries, root curvature ≥ 10°. Calcified canals. Pregnancy. systemic disorders and taking medications Perio - endo lesion