Anti-bacterial Potential of Nano Calcium Hydroxide as an Intracanal Medication

Inclusion Criteria: * healthy males and females. * age range between 21-49. * patients with no physical disability or psychological problems. * patients presenting with single permanent molar with signs and/or symptoms of apical periodontitis, and having Periapican index ≥ 2. Exclusion Criteria: * pregnant women. * patients with immune-compromised disease. * patients with complicated systemic diseases. * patients who took antibiotics within a period of 1 month. * patients with known sensitivity to the medicaments or pharmaceuticals used in this study. * Non-restorable teeth including root fractures, and/or advanced periodontal involvement.