title: Evaluation of working length determination methods: an in vivo / ex vivo study.
abstract: This comparative study was done to determine the accuracy in measuring the working length of root canal using tactile method, electronic apex locator and radiographic method, in vivo and comparing the lengths so measured to the actual working length, ex vivo, after extraction. Thirty single-rooted teeth scheduled for extraction were selected for the study. After obtaining the consent from patients, a preoperative radiograph was taken and access opening was done. Working length was determined by tactile method, by using Ingle's radiographic method and by using a Foramatron-IV digital apex locator. The teeth were then extracted and the actual working length was determined by placing an endodontic file in the root canal 0.5 mm short of the apex. The results indicated that among the three methods, the electronic apex locator showed the highest accuracy and the highest reliability for working length determination.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Sri Ramachandra Dental College and Research Institute (Deemed University), Porur, Chennai, India.
authors.forename: Muthu
authors.initials: M
authors.lastname: Shanmugaraj
authors.forename: Rajendran
authors.initials: R
authors.lastname: Nivedha
authors.forename: Rajan
authors.initials: R
authors.lastname: Mathan
authors.forename: Sundaresan
authors.initials: S
authors.lastname: Balagopal
mesh_terms: D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D004582:Electronics, Medical; D006801:Humans; D009811:Odontometry / Q000295:instrumentation*; D011861:Radiography, Dental; D015203:Reproducibility of Results; D012390:Root Canal Therapy / Q000295:instrumentation*; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging