title: An ex vivo comparison of electronic apex locator teaching models.
abstract: BACKGROUND
  This study aimed to develop a simple and inexpensive ex vivo model to teach students the use of electronic apex locators in a preclinical setting.
  
  
  METHODS
  Using 27 extracted human teeth, the Raypex 5 (VDW, Munich, Germany) and Dentaport ZX (J. Morita Co, Kyoto, Japan) were tested in three different media (ie, alginate, sugar-free gelatin, and 0.9% sodium chloride solution). Working lengths determined by these models were compared with those obtained by digital radiography and direct visualization using a linear mixed modeling statistical approach.
  
  
  RESULTS
  Raypex 5 exhibited a higher percentage of measurements accurate to ± 0.5 mm and ± 1.0 mm of the control across all three media in all tooth types. In multirooted teeth, alginate showed the highest accuracy.
  
  
  CONCLUSIONS
  The most accurate EAL/embedding medium combination was Raypex 5/alginate to both ± 0.5 mm and ± 1.0 mm of the control. The model tested in this study was accurate, easy to assemble, and cost-effective, making it suitable for teaching purposes.
authors.affiliation: Melbourne Dental School, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Elice
authors.initials: E
authors.lastname: Chen
authors.forename: Sivlee
authors.initials: S
authors.lastname: Kaing
authors.forename: Harry
authors.initials: H
authors.lastname: Mohan
authors.forename: Shin-Yeu
authors.initials: SY
authors.lastname: Ting
authors.forename: Jean
authors.initials: J
authors.lastname: Wu
authors.forename: Peter
authors.initials: P
authors.lastname: Parashos
mesh_terms: D000464:Alginates; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D004497:Education, Dental / Q000191:economics; D017097:Electric Impedance; D055615:Electrical Equipment and Supplies; D004708:Endodontics / Q000193:education*; D005780:Gelatin; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006801:Humans; D007552:Isotonic Solutions; D016014:Linear Models; D017145:Models, Educational; D009811:Odontometry / Q000295:instrumentation*; D019252:Radiography, Dental, Digital; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D007552:Isotonic Solutions; D020723:Glucuronic Acid; D005780:Gelatin