title: In Vitro Comparison of Raypex 6 and Endopilot Using a Novel, Computer-Aided Measurement System, for Determining the Working Length.
abstract: BACKGROUND
  Experimental evaluation of endometric devices usually relies on visual, subjective detection of the apical constriction to determine the accuracy of measurements. The aim of the present study was to analyze the accuracy of measurements of Raypex 6 and EndoPilot using a novel, objective image-analysis system.
  
  
  METHODS
  Onehundred and twenty teeth were randomized and allocated to three groups: After coronal flaring, either Raypex 6 or EndoPilot were used to determine the endodontic working length during instrumentation using manual files (RPM and EPM group respectively). In addition, EndoPilot was used for continuous, automatic measurement during rotating instrumentation (EPA group). If the working length had been reached according to endometric results, the files were fixed in place. Tooth and file were then embedded and prepared for analysis. Subsequently, the distance between the tip of the file and the apical constriction (DAC) or the apical foramen (DAF) was calculated using trigonometric analysis and the position of the file relative to AC and AF was analyzed.
  
  
  RESULTS
  Both inter- and intra-examiner-reliability of the trigonometric analysis were nearly perfect (ICC = 0.999, p<0.001). DAC was not significantly different between groups (p>0.05, t-test). DAF was significantly decreased when EPA had been used compared to EPM (p<0.05, Exact-test). EPA resulted in files being positioned beyond AF significantly more often than the other two methods (p<0.01).
  
  
  CONCLUSIONS
  All methods allowed reliable detection of AC. However, EPA significantly increased the risk of overpreparation. Objective, digital assessment based on image analysis was suitable to compare the accuracy of different endometric devices.
authors.affiliation: Clinic for Conservative Dentistry and Periodontology, School for Dental Medicine, Christian-Albrechts-University Kiel, Kiel, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Christofzik
authors.affiliation: Department of Operative and Preventive Dentistry, Charité Centrum 3, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Falk
authors.initials: F
authors.lastname: Schwendicke
authors.affiliation: Clinic for Conservative Dentistry and Periodontology, School for Dental Medicine, Christian-Albrechts-University Kiel, Kiel, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Flörke
authors.affiliation: Department of Computer Science, University of Miami, Coral Gables, Florida, United States of America.
authors.forename: Alexander
authors.initials: A
authors.lastname: Härtl
authors.affiliation: Clinic for Conservative Dentistry and Periodontology, School for Dental Medicine, Christian-Albrechts-University Kiel, Kiel, Germany.
authors.forename: Christof
authors.initials: C
authors.lastname: Dörfer
authors.affiliation: Clinic for Conservative Dentistry and Periodontology, School for Dental Medicine, Christian-Albrechts-University Kiel, Kiel, Germany.
authors.forename: Birte
authors.initials: B
authors.lastname: Größner-Schreiber
mesh_terms: D003786:Dental Pulp Cavity / Q000601:surgery*; D004582:Electronics, Medical / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D015203:Reproducibility of Results; D012390:Root Canal Therapy / Q000295:instrumentation*; D019227:Tooth Apex / Q000601:surgery*