Pain Following One-visit Versus Two-visit Root Canal of Necrotic Teeth Using Protaper Next

Inclusion criteria: * Medically free patients. * Patient's age above 18 years old. * Teeth diagnosed clinically with necrosis. * Positive patient's acceptance for participation in the study. * Sex includes both male and female. * Patients who can understand visual analogue scale. * Patients able to sign informed consent. Exclusion criteria: * Pregnancy or lactation. * Medically compromised patients. * Patient with multiple teeth that required treatment in the same quadrant to eliminate the possibility of pain referral.