Root canal morphology of mandibular first molars: Comparison of the diagnostic accuracy of cone‑beam computed tomography and the sectioning technique

Abstract

Background: A successful endodontic treatment requires a comprehensive knowledge of the
root canal morphology. This study compared the diagnostic accuracy of cone‑beam computed
tomography (CBCT) and the sectioning technique for the assessment of mandibular first
molar (MFM) root canal morphology.
Materials and Methods: In this in vitro, experimental study, 48 eligible MFMs were mounted in
12 blocks (groups of 4) made of acrylic resin and sheep bone powder and underwent CBCT. Next,
the teeth were mounted in transparent self‑cure acrylic blocks, and their roots were sectioned at
three points with 3 mm intervals. Images underwent multiplanar reconstruction in NNT Viewer
software and were analyzed by one radiologist with the cooperation of an endodontist. The sections
were also evaluated by an endodontist under a stereomicroscope (gold standard). The frequency and
percentage of single‑canal, and two‑canal roots were determined by each technique. The agreement
between CBCT and the Gold standard was analyzed by calculating the kappa coefficient (P < 0.05).
Results: The diagnostic accuracy of CBCT for the assessment of the MFM root canal morphology
was 80% on the mesial surface, 99% in the distal surface, and 96% in total. In the mesial surface,
94.2% of two‑canal roots and 66.7% of single‑canal roots were correctly detected by CBCT.
These values were 100% and 97.4% in the distal surface, and 95.2% and 95.8% in total, respectively.
A significant agreement was noted between CBCT and the Gold standard with κ =0.412 for the
mesial, 0.939 for the distal, and 0.907 for the total surfaces (P < 0.001).
Conclusion: CBCT can be reliably used for the assessment of the complex root canal morphology
of MFMs when other modalities fall short.
Key Words: Cone‑beam computed tomography, mandible, molar, tooth root

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Sanaz Sharifi shoshtari : Pubmed,Google Scholar