title: Postoperative endodontic pain of three different instrumentation techniques in asymptomatic necrotic mandibular molars with periapical lesion: a prospective, randomized, double-blind clinical trial.
abstract: OBJECTIVE
  The purpose of this prospective, randomized, double-blind study was to compare postoperative pain of root canal treatment in patients with asymptomatic mandibular molar teeth with necrotic pulp and periapical lesion using three different instrumentation techniques: hand, multi-file rotary (ProTaper Universal), and reciprocating single-file (Wave-One) instrumentation techniques.
  
  
  METHODS
  Ninety-six patients who fulfilled specific inclusion criteria were assigned to three groups according to the root canal instrumentation technique used: Hand (G1), ProTaper Universal (G2), and Wave-One (G3). One-visit root canal treatment was carried out, and the severity of the postoperative pain was assessed by the Heft-Parker visual analogue scale 6, 12, 18, 24, 48, and 72 h after treatment. Data were analyzed by Kruskal-Wallis, χ2, Cochrane Q, one-way ANOVA, and Spearman's correlation analyses (α = 0.05).
  
  
  RESULTS
  The patients in group 3 reported significantly lower postoperative pain levels at 6, 12, and 18 h compared with the patients in the two other groups (P < .05). In addition, the patients in group 2 reported significantly lower postoperative pain levels at 6 and 12 h compared with the patients in group 1 (P < .05). There were no significant differences in postoperative pain between the three groups at other time intervals (P > .05). The analgesic consumption was significantly higher in group 1 (P < .05), but no difference was seen between the two other groups (P > .05).
  
  
  CONCLUSIONS
  Postoperative pain was significantly lower in patients undergoing root canal instrumentation with the Wave-One file compared with the ProTaper Universal and hand files.
authors.affiliation: Department of Endodontics, School of Dentistry, AJA University of Medical Sciences, Tehran, 8174755153, Iran. ali_shokrane@dnt.mui.ac.ir.
authors.forename: Ali
authors.initials: A
authors.lastname: Shokraneh
authors.affiliation: Department of Endodontics, School of Dentistry, AJA University of Medical Sciences, Tehran, 8174755153, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Ajami
authors.affiliation: Department of Oral and Maxillofacial Radiology, School of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Nastaran
authors.initials: N
authors.lastname: Farhadi
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Hosseini
authors.affiliation: Department of Oral Medicine, School of Dentistry, AJA University of Medical Sciences, Tehran, Iran.
authors.forename: Bita
authors.initials: B
authors.lastname: Rohani
mesh_terms: D000328:Adult; D003762:Dental Instruments; D003790:Dental Pulp Necrosis / Q000601:surgery*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008963:Molar / Q000601:surgery; D010147:Pain Measurement; D010149:Postoperative Pain / Q000453:epidemiology*; D011446:Prospective Studies; D012390:Root Canal Therapy / Q000295:instrumentation*
keywords: Hand file; Heft-Parker visual analogue scale; ProTaper; Wave-One