Background: Intraoral radiographs (IRs) provide a two-dimensional view of osseous structures, whereas cone-beam volumetric tomography (CBVT) images are viewable in three dimensions. The aim of this investigation was to compare the measurements from digital IR and CBVT images to direct surgical measurements for the evaluation of regenerative treatment outcomes.
Methods: Digital IR and CBVT images were taken prior to initial bone grafting and at the 6-month reentry surgery for 35 intrabony defects. After defect debridement, direct bony defect measurements were made with a periodontal probe. These same measurements were made on the IR and CBVT images and then compared to the direct surgical values.
Results: CBVT correlated strongly with surgical measurements (r = 0.89 to 0.95), whereas IRs correlated less favorably (r = 0.53 to 0.67). IR measurements were significantly less accurate compared to CBVT for all parameters investigated and underestimated surgical measurements from 0.6 +/- 2.3 mm to 1.5 +/- 2.3 mm. No significant difference for the distance from the cemento-enamel junction (CEJ) to the alveolar crest (P = 0.66 for initial measurement and P = 0.92 for reentry), defect fill (P = 0.14), or defect resolution (P = 0.09) was seen between CBVT and surgical measurements; however, there was a significant difference for the distance from the CEJ to the base of the defect, with CBVT measurements underestimating the surgical measurements by 0.5 +/- 1.1 mm for reentry (P <0.01) and 0.9 +/- 0.8 mm for the initial measurement (P <0.01).
Conclusions: Overall, compared to direct surgical measurements, CBVT was significantly more precise and accurate than IRs. If supported by further research, CBVT may obviate surgical reentry as a technique for assessing regenerative therapy outcomes.