The detection of periapical pathoses in root filled teeth using single and parallax periapical radiographs versus...

To clinically assess the diagnostic yield from single parallel periapical, two parallax radiographs and cone beam computed tomography (CBCT) by comparing the prevalence of periapical lesions associated with individual roots, and the total number of root canals in root-treated teeth in patients referred for root canal retreatment.

Single and parallax periapical radiographs, and CBCT scans, were taken of 100 teeth in 78 patients who had been referred for root canal retreatment. The presence of a periapical lesion associated with each specific root and the number of identifiable root canals were assessed using each imaging modality by a consensus panel of two examiners. The number of root canals was confirmed using the dental-operating microscope during treatment. In addition, the panel was asked to decide whether they felt they had adequate information to manage each case.

A total of 209 paired roots were assessed for periapical lesions. Lesions were identified in 41%, 38% and 68% of paired roots when using single radiographs, two parallax radiographs and CBCT respectively. The number of root canals identified were 186, 218, 242 and 239 when using parallel, parallax, CBCT and the dental-operating microscope, respectively.

CBCT detected significantly more periapical lesions and root canals than both single and parallax periapical radiographs. There was no significant difference between CBCT and the clinical microscope in the identification of root canals. Whilst two parallax radiographs detect significantly more root canals than a single radiograph, they did not increase detection of periapical lesions when compared to a single periapical radiograph.