The aim of this prospective, randomized, clinical trial was to evaluate the effect of 1.3% sodium hypochlorite (NaOCl) concentration versus 5.25% NaOCl concentration on post-operative pain and medication intake in adult patients with pulp necrosis in mandibular molars.

The aim of this prospective, randomized, clinical trial was to evaluate the effect of 1.3% sodium hypochlorite (NaOCl) concentration versus 5.25% NaOCl concentration on post-operative pain and medication intake in adult patients with pulp necrosis in mandibular molars. Medical and dental history was obtained from all participants in this trial and clinical and radiographic evaluation for teeth was recorded. Participants with pulp necrosis with or without apical periodontitis were included. After access cavity preparation, participants were randomly assigned to one of the following groups: experimental group (irrigation using 1.3% NaOCl) or control group (irrigation using 5.25% NaOCl ). Two-visit root canal treatment was performed with a week interval in between visits. Each patient received a 7-day diary to record postoperative pain and rescue medication intake. Post-operative pain was measured at the following time points: immediately , 3, 24, 48 hours and 7 days after the first visit and postobturation.

Inclusion Criteria:

1. Age: 25-45 year old.
2. Medically free.
3. Non-vital mandibular teeth (first or second molar) with or without apical periodontitis
4. No sex predilection

Exclusion Criteria:

1. Pregnant females.
2. History of allergy to any medication used in the study.
3. Preoperative premedication 12 hours before procedure.
4. Acute abscess cases.
5. Badly-decayed crown.
6. Retreatment cases