title: Accuracy of Cone-Beam Computed Tomography in Determining the Root Canal Morphology of Mandibular First Molars.
abstract: BACKGROUND
  The aim of the present in vitro study was to compare the accuracy of cone-beam computed tomography (CBCT) in determining root canal morphology of mandibular first molars in comparison with staining and clearing technique.
  
  
  METHODS
  CBCT images were taken from 96 extracted human mandibular first molars and the teeth were then evaluated based on Vertucci's classification to determine the root canal morphology. Afterwards, access cavities were prepared and India ink was injected into the canals with an insulin syringe. The teeth were demineralized with 5% nitric acid. Finally, the cleared teeth were evaluated under a magnifying glass at 5× magnification to determine the root canal morphology. Data were analyzed using the SPSS software. The Fisher's exact test assessed the differences between the mesial and distal canals and the Cohen's kappa test was used to assess the level of agreement between the methods. Statistical significance was defined at 0.05.
  
  
  RESULTS
  The Kappa coefficient for agreement between the two methods evaluating canal types was 0.346 (95% CI: 0.247-0.445), which is considered a fair level of agreement based on classification of Koch and Landis. The agreement between CBCT and Vertucci's classification was 52.6% (95% CI: 45.54-59.66%), with a significantly higher agreement rate in the mesial canals (28.1%) compared to the distal canals (77.1%) (P<0.001).
  
  
  CONCLUSIONS
  Under the limitations of this study, clearing technique was more accurate than CBCT in providing accurate picture of the root canal anatomy of mandibular first molars.
authors.affiliation: Dental and Periodontal Research Center, Department of Endodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran;
authors.forename: Hadi
authors.initials: H
authors.lastname: Mokhtari
authors.affiliation: Department of Oral and Maxillofacial Radiology, Dental School, Tehran University of Medical Sciences, Tehran, Iran;
authors.forename: Mahdi
authors.initials: M
authors.lastname: Niknami
authors.affiliation: Dental and Periodontal Research Center, Department of Endodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran;
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Mokhtari Zonouzi
authors.affiliation: Department of Orthodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran;
authors.forename: Aydin
authors.initials: A
authors.lastname: Sohrabi
authors.affiliation: Dental and Periodontal Research Center, Department of Endodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran;
authors.forename: Negin
authors.initials: N
authors.lastname: Ghasemi
authors.affiliation: Private Practitioner, Tabriz, Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Akbari Golzar
keywords: Cone-Beam Computed Tomography; Root Canal Morphology; Root Clearing