Comparison of the accuracy of apex locator, digital radiography, and cone‑beam computed tomography in root canal working length determination in teeth with external root resorption: An in vitro study

Abstract

Background: The aim of this study was to compare the accuracy of apex locator, digital periapical
radiography, and cone‑beam computed tomography (CBCT) for determining the root canal working
length (WL) in teeth with external root resorption (ERR).
Materials and Methods: In this in vitro study, the sample consisted of 54 extracted permanent
single‑rooted human teeth. ERRs were performed at the 3 mm apical root using 65% of nitric
acid for 24 h. After determining the actual WL by K‑file #10 (gold standard) with the visualization
method, the teeth were mounted in alginate and the WL of each tooth was determined using the
electronic apex locator (EAL) equipped with a K‑file #15. The teeth were mounted with wax in
the teeth sockets of a dry human mandible, and the images were obtained by digital phosphor plate
receptors and CBCT scans. The mean registered WL of each method was statistically compared
with the gold standard WL using one‑way ANOVA with P < 0.001.
Results: The mean ± standard deviation (SD) of actual WL was 16.00 ± 2.24. The mean ± SD
of WLs determined by CBCT, EAL, and digital radiography were 15.38 ± 2.19, 15.52 ± 2.32, and
16.83 ± 2.20, respectively. This study showed that the mean measured WL with ERR in all methods
was significantly different from the actual WL (P < 0.001).
Conclusion: This study showed that there was a significant difference between the actual mean
WL and the EAL, digital periapical radiography, and CBCT mean WL. Thus, the combination of EAL
and CBCT could be a reliable method for determining WL in the presence of ERR.
Key Words: Cone‑beam computed tomography, digital radiography, endodontics, radiographic image enhancement, root resorption

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Seyed Mohsen Hasheminia: Pubmed,Google Scholar