Accuracy of cone beam computed tomography for periodontal defect measurements

Periodontal diagnosis relies heavily on traditional two-dimensional radiographic assessment. Despite efforts in improving reliability, current methods of detecting bone level changes over time or determining three-dimensional architecture of osseous defects are inadequate. To address these issues, computed tomography (CT) has been explored because of its ability to produce accurate three-dimensional imaging, but limitations such as radiation, machine size, and cost have made this approach impractical. Recently, cone beam computed tomography (CBCT) has turned this concept into potential reality because these lower-cost small machines produce high-quality data. Yet there is little research to establish periodontal bone measurement using CBCT as a valid method. Therefore, the aim of this study was to compare CBCT measurements of periodontal defects to traditional methods.

Artificial osseous defects were created on mandibles of dry skulls. CBCT scanning, periapical radiography (PA), and direct measurements using a periodontal probe were compared to an electronic caliper that was used as a standard reference.

Linear measurements for all defects revealed no statistical differences between bone sounding, radiography, and CBCT. There was a significant difference when comparing isolated interproximal measurements using a probe versus the caliper (P<0.001) but no significant difference for CBCT or radiography. All bony defects were identifiable and measurable directly or with CBCT. In comparison, buccal and lingual defects could not be measured with radiographs.

Overall, all three modalities are useful for identifying interproximal periodontal defects. Compared to radiographs, the three-dimensional capability of CBCT offers a significant advantage because all defects can be detected and quantified.