The use of cone-beam computed tomography and digital periapical radiographs to diagnose root perforations

Introduction
The aim of this study was to compare the sensitivity and specificity of cone-beamcomputedtomography (CBCT) scans and digitalperiapicalradiographs (PR) in detecting strip and rootperforations after root canal treatment in mandibular molars.

Methods
Forty-five curved mesial roots were endodontically prepared. Fifteen roots were perforated in the mesiolingual canal by inserting a rotary file through the canal curvature penetrating the root surface ("rootperforation"), and 15 roots were perforated with a drill in the axial aspect of the canal ("strip perforation"). Fifteen roots were not perforated. All mesial roots were filled with gutta-percha and AH26. Teeth were then placed in human mandibles. PRs from two angulations and CBCT scans were evaluated by two observers. The sensitivity and specificity of both methods to diagnoseperforations were calculated.

Results
The sensitivity and specificity of CBCT scans in the detection of strip perforations were 0.50 and 0.97, respectively, and with two-angled PRs they were 0.13 and 0.97. For the detection of rootperforations, the sensitivity and specificity of CBCT scans were 0.86 and 0.70, respectively, and for PRs they were 0.66 and 0.90. The difference between PRs and CBCT scans in detecting strip perforations was significant (chi-square test, P < .05).

Conclusions
The risk to misdiagnose strip perforations was high with both methods, but CBCT scans showed a significant higher sensitivity than PR. There was no significant difference between the methods for the detection of rootperforations.