Incidence of Post-operative Pain After Single-visit Versus Two-visit Treatment

Inclusion Criteria: 1. The aims and requirements of the study were freely accepted; 2. Treatment was limited to patients in good health; 3. All teeth had nonvital pulps and apical periodontitis, with or without a sinus tract; 4. A negative response to hot and cold pulp sensitivity tests; 5. Presence of sufficient coronal tooth structure for rubber dam isolation; 6. No prior endodontic treatment on the involved tooth 7. No analgesics or antibiotics were used five days before the clinical procedures began. Exclusion Criteria: 1. Patients who did not meet inclusion requirements; 2. Patients who did not provide authorization for participation; 3. Patients who were younger than 16 years old; 4. Patients who were pregnant; 5. Patients who were diabetic; 6. Patients with a positive history of antibiotic use within the past month; 7. Patients whose tooth had been previously accessed or endodontically treated; 8. Teeth with root resorption, 9. Immature/open apex, or a root canal in which patency of the apical foramen could not be established were all excluded from the study. Teeth with periodontal pockets deeper than 4 mm also were excluded of the study.