title: Comparative study of periapical radiographic techniques with apex locator for endodontic working length estimation: an ex vivo study.
abstract: BACKGROUND
  Accurate assessment of working length determines the success and prognosis of an endodontic treatment outcome. Various methods are used in determining the working length.
  
  
  OBJECTIVE
  Compare the measurements of the apex locator and radiographic technique to determine working length.
  
  
  METHODS
  An ex vivo study was conducted on 20 patients having intact single straight root canal. Only premolars were taken in the study. After doing coronal flaring and irrigation, the radiographic length was determined with an aid of a k-type file and electronic length (EL-Root-ZX) 3rd generation apex locator. After extraction of all the premolars, stereomicroscope was further used to confirm and compare radiographic and electronic apex locator.
  
  
  RESULTS
  A mean value of 0.5430 ± 0.5741 mm was observed among radiographic techniques. A mean value of 0.4240 ± 0.4587 mm was observed among apex locator techniques. T-test revealed, no significant difference between the two techniques was observed (p = 0. 615). 'Two tailed' t-test revealed intragroup significance both techniques for determining the working length.
  
  
  CONCLUSIONS
  The distance of the apical foramen to the tip of the file: A mean value of 0.4240 ± 0.4587 mm with apex locator technique was observed. Working length of apex locator was more in comparison to radiographic technique. No significant difference between the two techniques was observed (p = 0. 615). Intragroup significance among both techniques for determining the working length was also observed. However, a further study incorporating a larger sample size and utilization of both techniques of working length determination on the same tooth has to be conducted.
  
  
  CONCLUSIONS
  Combining the apex locator technique and radiographic technique for determination of working length would yield more accurate working length.
authors.affiliation: Department of Conservative Dentistry and Endodontics, KM Shah Dental College and Hospital, Sumandeep Vidyapeeth, Vadodara, Gujarat, India.
authors.forename: Vaishali
authors.initials: V
authors.lastname: Parekh
authors.forename: Chirag
authors.initials: C
authors.lastname: Taluja
mesh_terms: D001641:Bicuspid / Q000000981:diagnostic imaging; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D006801:Humans; D009811:Odontometry / Q000295:instrumentation* / Q000379:methods; D011859:Radiography; D018915:Root Canal Preparation / Q000295:instrumentation*; D019227:Tooth Apex / Q000000981:diagnostic imaging*