Inclusion Criteria:  Mature permanent restorable mandibular molar teeth. Tooth should give positive response to pulp sensibility testing. Clinical diagnosis of irreversible pulpitis with PAI score≤2. Tooth with probing pocket depth and mobility are within normal limits. Non-contributory medical history.  Exclusion Criteria:  Teeth with immature roots. No pulp exposure after caries excavation. Bleeding could not be controlled in 6 minutes. Insufficient bleeding after pulp exposure, the pulp is judged necrotic or partially necrotic. Absence of antagonist tooth. Positive history of antibiotic use in the past 1 month or requiring antibiotic prophylaxis Had taken analgesic in past 3 days. Tooth with periapical lesion visible on radiograph