title: Effect of working length measurement by electronic apex locator or digital radiography on postoperative pain: a randomized clinical trial.
abstract: BACKGROUND
  The aim of this study was to evaluate the effect of working length determination methods, electronic apex locator and digital radiography, on postoperative pain.
  
  
  METHODS
  Two hundred twenty patients with asymptomatic single-rooted vital teeth were randomly assigned to 2 groups according to the method used for working length determination, the radiographic group and the electronic apex locator group. After working length determination, chemomechanical preparation was performed in a crown-down technique with ProTaper instruments. A master cone radiograph was taken. Canals were obturated with gutta-percha and sealer by using a lateral compaction technique. Postoperative pain was assessed after 4, 6, 12, 24, and 48 hours by using a 4-point pain intensity scale. In addition, patients were asked to record the number of days necessary to achieve complete pain resolution.
  
  
  RESULTS
  Postoperative pain during the 4-hour to 48-hour interval studied was not significantly different (P > .05) between groups. The mean times for pain dissipation in the radiographic and electronic apex locator groups were 3.37 ± 2.79 and 3.88 ± 3.34 days, respectively. The difference between groups was not statistically significant (P > .05).
  
  
  CONCLUSIONS
  There is no difference in postoperative pain between working length measurement methods by using an electronic apex locator or digital radiography. The reduced exposure to radiation by using apex locator may be a factor that influences a dentist's decision to choose the electronic apex locator over radiography.
authors: Department of Endodontics, Faculty of Dentistry, Bezmialem Vakif University, Istanbul, Turkey. Electronic address: aysunkara80@gmail.com.
authors: Aysun
authors: A
authors: Kara Tuncer
authors: Private Practice, Istanbul, Turkey.
authors: Müzeyyen
authors: M
authors: Gerek
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D003657:Decision Making; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D055615:Electrical Equipment and Supplies; D005260:Female; D005480:Flurbiprofen / Q000627:therapeutic use; D005500:Follow-Up Studies; D006171:Gutta-Percha / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009811:Odontometry / Q000295:instrumentation*; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000209:etiology*; D011670:Pulpectomy / Q000295:instrumentation; D011671:Pulpitis / Q000628:therapy; D016300:Radiography, Bitewing / Q000379:methods; D019252:Radiography, Dental, Digital / Q000379:methods*; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation*; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D055815:Young Adult
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D012387:Root Canal Filling Materials; D005480:Flurbiprofen; D006171:Gutta-Percha
keywords: Digital radiography; electronic apex locators; postoperative pain; root canal treatment; working length determination