Digital radiographs displayed on different devices: effect on the detection of vertical root fractures

To evaluate whether the type of display device affects the detection of vertical root fractures (VRFs) on digital radiographs in unfilled canals and canals with fibreglass posts.

Forty single-rooted human teeth were decoronated, and the root canals were prepared. The teeth were divided into 2 groups: controls (20 teeth) and with VRF (20 teeth). The VRFs were induced using an universal testing machine. Periapical radiographs of all teeth, with canal unfilled or with a fibreglass post, were obtained using the parallel technique in 3 directions (ortho-, mesio- and distoradial) on storage phosphor plates (VistaScan®). All images were evaluated and re-evaluated after 30 days by 3 examiners on a 5-point scale using 4 different devices (notebook display with full high definition resolution, desktop display with a standard resolution, 8-inch Android(™) tablet with high definition resolution and a 9.7-inch iPad® tablet with Retina resolution). Areas under ROC curves, sensitivity, specificity and accuracy values were compared by anova.

The weighted kappa values for intra- and interobserver reproducibility were 0.55-0.88 and 0.31-0.65, respectively. There was a significant difference (P < 0.05) in relation to the area under the ROC curve, specificity and sensitivity when unfilled canals were compared with canals with a fibreglass post; however, no difference was observed for the different devices studied.

The type of display device did not affect the detection of VRFs. Thus, the detection of VRFs can be performed using different screen sizes and resolutions.