title: A tactile method for canal length determination in teeth with open apices.
abstract: OBJECTIVE
  To present a tactile method for working length determination in teeth with open apices and to determine its accuracy and repeatability.
  
  
  METHODS
  Ninety teeth with 129 root canals were prepared to create open apices. The correct working length (CWL) for each canal was determined by introducing a file into the root canal until it was visible at the apex. Consequently, the tactile working length (TWL) was determined by the 'Tactile Method' using a K-file that was bent at the tip. Two operators repeated the measurement once in each root canal. The accuracy of the TWL was determined by comparing the TWL with the CWL. The mean of the absolute differences and the corresponding 99% confidence interval (CI) were calculated. Both the repeatability and inter-operator agreement of the tactile method were determined by performing paired analysis of the differences between repeated measurements and the two operators.
  
  
  RESULTS
  Overall, 97% (CI: 91-99) of the TWL were within 0.5 mm from the CWL, the mean of absolute differences was 0.1 mm (CI: 0.1-0.2). The maximum difference between repeated measurements was 0.2 mm and between the two operators was 0.6 mm.
  
  
  CONCLUSIONS
  The tactile method may provide an accurate determination of canal length in teeth with open apices.
authors.affiliation: Department of Conservative Dentistry and Endodontology, University of Tübingen, 72076 Tübingen, Germany. ashraf.elayouti@med.uni-tuebingen.de
authors.forename: A
authors.initials: A
authors.lastname: ElAyouti
authors.forename: E
authors.initials: E
authors.lastname: Dima
authors.forename: C
authors.initials: C
authors.lastname: Löst
mesh_terms: D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D006801:Humans; D015588:Observer Variation; D009811:Odontometry / Q000295:instrumentation / Q000379:methods*; D012044:Regression Analysis; D015203:Reproducibility of Results; D018915:Root Canal Preparation / Q000295:instrumentation*; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000254:growth & development; D014110:Touch