A comparative investigation of cone-beam computed tomography and periapical radiography in the diagnosis of a healthy periapex.

By Pope O, Sathorn C, Parashos P.

Date: 01/2014
Journal: JOE


Compare appearance of healthy periapical tissues in cone-beam with PA and measure PDL on CBCT in health vs necrosis


N=200 teeth that had PA, pulp tested, and CBCT from endodontists

  • 2 independent, blind examiners  analyzed the images using a modified CBCT-PAI (CBCT- Periapical Index) score and PAI score for PA radiographs
  • Fisher exact and X(2) analysis for relationships between CBCT-PAI, PAI, and pulp status


  • 166 out of 200 were vital
  • 72 % CBCT-PAI was greater than PAI in vital teeth with radiographic PDL widening of 0-1 mm (p< 0.001)
  • 2 healthy teeth showed 2-4 mm radiolucencies on CBCT when PA radiograph showed none
  • In 20% of vital teeth had CBCT-PAI of 2+
  • PDL > 1-2 mm was indicative of a necrotic pulp (p< 0.001)

Clinical Significance:

  1. Teeth with necrotic pulps were more likely to have PDL widening
  2. Most healthy teeth showed some widening
  3. The normal 3-dimensional anatomy of the PDL space appears to entail greater variation than previously thoughtà questions traditional radiographic interpretation
  4. CBCT must be further investigated before usage in outcome or epidemiological investigations