title: In vitro evaluation of three electronic apex locators using conventional methods and cone beam computed tomography.
abstract: OBJECTIVE
  The aim of this paper was to evaluate the measurement accuracy of three electronic apex locators by digital radiography, stereomicroscope and cone beam computed tomography (CBCT).
  
  
  METHODS
  This in vitro experimental analytic-descriptive study included 90 extracted permanent teeth with mature apices from the inter-canine region, divided into three groups. In vitro electronic root canal measurement was utilized using three different apex locators: ProPex Dentsply, Apex NRG Blue and Romi Apex 15A. After digital radiographic imaging and measurements Cone Beam Computer Tomography (CBCT) imaging with voxel edge size 0.125 mm was utilized and finally the apical portion of the root is grounded (5 mm) along its axis to prepare it for stereomicroscopic measurements.
  
  
  RESULTS
  The performed test of significance shows that there is no difference between the apex locators and the control length as measured by computed digital radiography (CDR), P-values of the t-tests are all >0.05. The t-tests showed that there is no significant differences between the measurements conducted by stereomicroscope and the measurements results obtained using CBCT; measurements performed by the three apex locators (Propex, NRG-Blue, and Rami Apex), were accurate within 0.5 mm 87%, 93%, and 87% of the time, respectively. The statistical analysis showed no significant differences between the three tested apex locators (P>0.05).
  
  
  CONCLUSIONS
  Based on the conditions of the present study, it can be concluded that all three apex locators (ProPex Dentsply, Apex NRG Blu and Romi Apex 15A) have demonstrated accurate and dependable measurements performed in vitro conditions.
authors.affiliation: Department of Dental Pathology and Endodontics, Faculty of Medicine University of Prishtina, Prishtina, Kosovo - shefqetmrasori@gmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Mrasori
authors.forename: R
authors.initials: R
authors.lastname: Budina
authors.forename: F
authors.initials: F
authors.lastname: Dragidella
mesh_terms: D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging* / Q000502:physiology / Q000648:ultrastructure; D025802:Electric Capacitance; D017097:Electric Impedance; D004568:Electrodiagnosis / Q000295:instrumentation*; D006801:Humans; D066298:In Vitro Techniques; D009061:Mouth Mucosa / Q000502:physiology; D009811:Odontometry / Q000379:methods*; D015203:Reproducibility of Results; D018915:Root Canal Preparation / Q000379:methods; D019227:Tooth Apex / Q000000981:diagnostic imaging* / Q000648:ultrastructure