Influence of a handheld X-ray unit in the diagnosis of proximal caries lesions using different digital systems.

Objectives: To assess the influence of a handheld X-ray unit in the diagnosis of proximal caries lesions using different digital systems by comparing with a wall-mounted unit.

Methods: Radiographs of 40 human teeth were acquired using the Eagle X-ray handheld unit (Alliage, São Paulo, Brazil) set at 2.5 mA, 60 kVp and an exposure time of 0.45 s. Then, new radiographs of the teeth were acquired using the Focus X-ray wall-mounted unit (Instrumentarium, Tuusula, Finland) set at 7 mA, 60 kVp, and exposure time of 0.16 s. Three digital systems were used: a photostimulable phosphor plate receptor (Express system) and two complementary metal oxide semiconductor sensors (Digora Toto and SnapShot systems). Five oral and maxillofacial radiologists individually assessed the radiographs. Area under the receiver-operating characteristic curve (AUC), sensitivity, and specificity were calculated from the responses of the examiners and compared using Analysis of Variance at a significance level of 5%. The weighted Kappa index evaluated the intra- and inter-examiner agreements for caries lesions diagnosis.

Results: The handheld X-ray unit did not influence on the diagnostic metrics for the three digital systems used when compared with the wall-mounted unit (p > 0.05). The SnapShot showed higher AUC value than Digora Toto (p < 0.05). The mean values of intra- and inter-examiner agreements were 0.654 (substantial) and 0.365 (fair), respectively.

Conclusions: The diagnostic accuracy for detecting proximal caries lesions is not influenced by the use of a handheld X-ray unit, regardless of the digital system used.