Agreement between periapical radiographs and cone-beam computed tomography for assessment of periapical status of root filled molar teeth.

By Cheung GS, Wei WL, McGrath C

Date: 05/2014
Journal: IEJ


To assess the agreement between periapical radiograph (PA) and cone-beam computed tomography (CBCT) for periapical assessment of root filled maxillary and mandibular molars.


  • N= 60 teeth
  • Exclusion criteria: N/A
  • Inclusion criteria: Patients who had received RCT of max/mand molar in a dental teaching hospital between 2001-2005.
  • Positive/negative control: N/A
  • Control & Design: Patients were recalled that had RCT performed between 2001-2005. One intraoral paralleling radiograph  w/size 2 x-ray film and XCP. In-house CBCT was then performed. 2 Pre-calibrated examiners (Endodontist, Oral radiologist) then examined the films. PA’s were measured using stainless steel ruler. CBCT images assessed using iCAT Vision.
  • Criteria of evaluation: Mean difference in (i) number of canals per tooth, (ii) number of lesions per tooth, (iii) M-D diameter of lesions, (iv) C-A diameter of lesions and (v) number of ‘J’ shaped lesions was compared.


  • No significant differences between Endodontist and Radiologist findings
  • Significant differences in: mean number of canals identified, mean number of lesions identified, size of lesions  (M/D, C/A), J shape lesions (few cases).
  • Discrepancy more pronounced in maxillary molars in terms of presence/size of lesion

Clinical Significance:

CBCT has some obvious advantages to PA in terms of identification of lesions/canals. Consideration need be given to exposure vs. benefit however. Also, the study is limited due to only having one endodontist/radiologist and could benefit from an increased sample size.