title: In vivo accuracy of three electronic root canal length measurement devices: Dentaport ZX, Raypex 5 and ProPex II.
abstract: OBJECTIVE
  To compare in vivo three different electronic root canal length measurement devices: Dentaport ZX, Raypex 5 and ProPex II.
  
  
  METHODS
  Thirty single-rooted permanent teeth scheduled for extraction because of periodontal disease were selected from 10 adult patients (ranging from 45 to 67 years) and divided into three groups of 10 teeth. Before the extraction, an access cavity was prepared and the crown was adjusted to establish a stable reference point for all measurements. The working length in Group 1 was determined using the Dentaport ZX apex locator. A K-file with the largest diameter that could reach the last green bar on the screen was stabilized in the canal using a dual-curable flow resin composite. The same procedure was used for the Raypex 5 (the file reached the last yellow bar) and Propex II (0.0 orange bar) apex locators. The teeth were then extracted and cleared. The distance between the tip of the file and the major foramen was then calculated for each tooth using digital photography according to Axiovision AC software (Carl Zeiss). Positive values were assigned when the file tip passed beyond the major foramen, negative values when the tip was short of the foramen and zero value when the file tip and the foramen coincided. Statistical analysis was performed using the chi-squared test or Fisher's exact test (P ≤ 0.05).
  
  
  RESULTS
  Dentaport ZX, Raypex 5 and ProPex ΙΙ produced, respectively, 6, 2 and 4 out of 10 correct measurements, 0, 6 and 5 long measurements and 4, 2, and 1 short measurements. The differences between the three electronic root canal length measurement devices were not significant (P = 0.507).
  
  
  CONCLUSIONS
  Under the in vivo conditions of this study, the three electronic root canal length measurement devices were not significantly different in terms of locating the major foramen.
authors.affiliation: Departments of Endodontics Clinic and Pathology Biomaterial, Catholic University of the Sacred Heart, Rome, Italy. francesco.somma@libero.it
authors.forename: F
authors.initials: F
authors.lastname: Somma
authors.forename: R
authors.initials: R
authors.lastname: Castagnola
authors.forename: C
authors.initials: C
authors.lastname: Lajolo
authors.forename: L
authors.initials: L
authors.lastname: Paternò Holtzman
authors.forename: L
authors.initials: L
authors.lastname: Marigo
mesh_terms: D000368:Aged; D001641:Bicuspid / Q000033:anatomy & histology; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D017097:Electric Impedance; D055615:Electrical Equipment and Supplies / Q000592:standards; D004867:Equipment Design; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007180:Incisor / Q000033:anatomy & histology; D008297:Male; D008853:Microscopy / Q000295:instrumentation; D008875:Middle Aged; D009811:Odontometry / Q000295:instrumentation* / Q000592:standards; D010781:Photography / Q000379:methods; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D019227:Tooth Apex / Q000033:anatomy & histology*