title: Radiographic identification of separated instruments retained in the apical third of root canal-filled teeth.
abstract: BACKGROUND
  The aim of the study was to compare the diagnostic ability to radiographically detect separated stainless steel (SS) versus nickel-titanium (NiTi) instruments located at the apical third of filled root canals with either AH 26 (Dentsply DeTrey GmbH, Konstanz, Germany) or Roth sealer (Roth International Ltd, Chicago, IL).
  
  
  METHODS
  Sixty single-rooted extracted human teeth with 1 straight root canal were instrumented to a size 25 apical diameter. In 40 teeth, apical 2-mm segments of SS (n = 20) or NiTi (n = 20) files were intentionally fractured in the apical part of the root canal. The remaining 20 teeth without fractured files served as a control group. Subsequently, the root canals were filled using laterally condensed gutta-percha and either AH 26 sealer (AH) or Roth sealer (Roth). All teeth were radiographed using conventional Kodak film (Eastman Kodak Co, Rochester, NY) and a charge-coupled device digital sensor. The evaluation of the images for the presence of a fractured instrument was performed independently by 2 blinded observers. The data were statistically analyzed using McNemar and Fisher exact tests.
  
  
  RESULTS
  The kappa values were 0.76 and 0.615 for the first and second observers, respectively, and 0.584 between the observers. There were no significant differences in the diagnostic ability between digital and conventional radiography or the different root canal sealers (AH vs Roth, P > .05). The sensitivity to detect fractured SS was significantly higher than NiTi (P < .05).
  
  
  CONCLUSIONS
  It may be difficult to radiographically detect a retained separated instrument. It is easier to radiographically detect fractured SS than NiTi instruments retained at the apical third of the root canal.
authors.affiliation: Department of Endodontology, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel. Electronic address: dr.eyalrosen@gmail.com.
authors.forename: Eyal
authors.initials: E
authors.lastname: Rosen
authors.affiliation: Private Practice, Tel Aviv, Israel.
authors.forename: Hadas
authors.initials: H
authors.lastname: Azizi
authors.affiliation: Department of Endodontology, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Clara
authors.initials: C
authors.lastname: Friedlander
authors.affiliation: University of Milan, Department of Biomedical, Surgical and Dental Science, Centre for Research in Oral Health, IRCCS IstitutoOrtopedicoGaleazzi, Milan, Italy.
authors.forename: Silvio
authors.initials: S
authors.lastname: Taschieri
authors.affiliation: Department of Endodontology, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Igor
authors.initials: I
authors.lastname: Tsesis
mesh_terms: D001729:Bismuth / Q000627:therapeutic use; D003722:Dental Alloys / Q000737:chemistry*; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging*; D004853:Epoxy Resins / Q000627:therapeutic use; D005547:Foreign Bodies / Q000000981:diagnostic imaging*; D006171:Gutta-Percha / Q000627:therapeutic use; D006801:Humans; D009532:Nickel / Q000737:chemistry*; D019252:Radiography, Dental, Digital / Q000379:methods* / Q000706:statistics & numerical data; D011897:Random Allocation; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000009:adverse effects / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D012834:Silver / Q000627:therapeutic use; D013193:Stainless Steel / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry* / Q000627:therapeutic use; D019227:Tooth Apex / Q000000981:diagnostic imaging*; D019553:Tooth, Nonvital / Q000000981:diagnostic imaging; D014962:X-Ray Film; D014963:X-Ray Intensifying Screens; D015035:Zinc Oxide-Eugenol Cement / Q000627:therapeutic use
chemical_list: D003722:Dental Alloys; D004853:Epoxy Resins; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C040654:titanium nickelide; D013193:Stainless Steel; D012834:Silver; C028044:epoxy resin AH-26; D009532:Nickel; D006171:Gutta-Percha; D014025:Titanium; D001729:Bismuth
keywords: Complication, radiography, root canal–filled teeth, separated instrument