Postendodontic pain in asymptomatic necrotic teeth prepared with different rotary instrumentation techniques.

Objectives: to investigate the postendodontic pain in asymptomatic necrotic teeth prepared with different rotary instrumentation techniques after single-visit root canal treatment.

Materials And Methods: A total of 60 single-rooted teeth with single root canal were treated endodontically. Teeth were divided randomly into four equaled groups ( = 15) according to instrumentation systems as follows: group I were shaped using ProTaper Universal (control group) (Dentsply/Maillefer, Ballaigues), group 2 were shaped with 2Shape (Micro-Mega) till TS2 (25.