title: Comparison of Manual and Rotary Instrumentation on Postoperative Pain in Teeth with Asymptomatic Irreversible Pulpitis: A Randomized Clinical Trial.
abstract: BACKGROUND
  One of the most common complications of root canal treatment is postoperative pain. The aim of the present clinical trial was to compare the severity of postoperative pain after root canal preparation with RaCe rotary system and hand K-Flexofile.
  
  
  METHODS
  A total of 96 mandibular first and second molars were divided into two groups (n=48) based on root canal preparation technique. The teeth in both groups underwent one-session root canal treatment and the severity of postoperative pain was evaluated using visual analog scale (VAS) at 4-, 8-, 12-, 24- and 48-h and 1-week intervals. In addition, the type and dosage of analgesics were recorded. Data were analyzed with repeated-measures ANOVA. Statistical significance was set at 0.05.
  
  
  RESULTS
  The difference between the two groups during this period and at subsequent intervals were not significant (P>0.05). There were no significant differences between the two groups in type and the number of analgesics in pain-free subjects (P=0.12 andP=0.61, respectively).
  
  
  CONCLUSIONS
  There were no statistically significant differences in pain severity between the two groups at any intervals.
authors: Endodontist, Department of Endodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Bita
authors: B
authors: Talebzadeh
authors: Dental and Periodontal Research Center, Department of Oral and Maxillofacial Surgery, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Saeed
authors: S
authors: Nezafati
authors: Dental and Periodontal Research Center, Department of Endodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Saeed
authors: S
authors: Rahimi
authors: Dental and Periodontal Research Center, Department of Endodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Shahriar
authors: S
authors: Shahi
authors: Department of Endodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Mehrdad
authors: M
authors: Lotfi
authors: Department of Endodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Negin
authors: N
authors: Ghasemi
keywords: Manual Instrumentation; Postoperative Pain; Root Canal Preparation; Rotary Instrumentation