title: Comparison of Single Visit Post Endodontic Pain Using Mtwo Rotary and Hand K-File Instruments: A Randomized Clinical Trial.
abstract: OBJECTIVE
  Pain is an unpleasant outcome of endodontic treatment that can be unbearable to patients. Instrumentation techniques may affect the frequency and intensity of post-endodontic pain. This study aimed to compare single visit post endodontic pain using Mtwo (NiTi) rotary and hand K-file instruments.
  
  
  METHODS
  In this randomized controlled trial, 60 teeth with symptomatic irreversible pulpitis in 53 patients were selected and randomly assigned into two groups of 30 teeth. In group A, the root canals were prepared with Mtwo (NiTi) rotary instruments. In group B, the root canals were prepared with hand K-file instruments. Pain assessment was implemented using visual analog scale (VAS) at four, eight, 12 and 24 hours after treatment. The acquired data were analyzed using chi-square, Mann-Whitney U and Student's t-test (P<0.05).
  
  
  RESULTS
  Patients treated with rotary instruments experienced significantly less post-endodontic pain than those treated with hand instruments (P<0.001).
  
  
  CONCLUSIONS
  The use of Mtwo (NiTi) rotary instruments in root canal preparation contributed to lower incidence of postoperative pain than hand K-files.
authors.affiliation: Assisstant Professor, Dental Material Research Center, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran; Department of Endodontics, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Kashefinejad
authors.affiliation: Assisstant Professor, Dental Material Research Center, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran; Department of Endodontics, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Azade
authors.initials: A
authors.lastname: Harandi
authors.affiliation: Dental Student, Student Research Committee, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Eram
authors.affiliation: Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Bijani
keywords: Endodontics; Pain; Pulpitis; Root Canal Therapy