The aim of this study was twofold: (i) to analyse the diagnostic accuracy of pathologies in three different imaging modalities of the same case and (ii) to analyse the need for further imaging in order to enable treatment. Further, aspects like the impact of specialisation, gender and dental experience were analysed. In contrast to the plethora of scientific literature available dealing with CBCT image accuracy, not much research has been conducted on how CBCT data are being contextually handled. This present investigation was designed to increase our understanding in this specific area.

The first objective was not only to analyse if diagnostic accuracy of residents is improved when assessing a CBCT (compared to an OPG), but to dissect the data and evaluate whether the diagnostic accuracy varies when assessing different pathologies, and whether professional background would account for the performance. Although a general increase of more correct answers could be observed for the assessment of CBCT compared to OPG (Figs. 1 and 2), the impact of CBCT was not present in every case when establishing the effect for each clinical question. Somewhat unexpectedly, comparable diagnostic accuracy could be attained already with an OPG for many diagnosed pathologies. Professional background had likewise a very small influence, as specialisation affected only the correctness of three answers moderately, and age, gender and years of experience as a dentist showed no effect at all. In short, only questions relating to resorption of dental or bony tissue, contact to nerve and maturation stage of the root reached significantly higher percentages for the residents in oral surgery group.

Comparable improvement in diagnostic accuracy was shown in previous studies [13] when comparing CBCT to OPG, and there is a broad consensus on the added value of CBCT imaging in diagnostics and treatment planning compared to a two-dimensional imaging [13,14,15,16,17,18,19,20,21,22,23]. Our results are in full agreement with these publications, yet highlight the fact that dental education may influence diagnostic accuracy, depending on the pathology to be assessed.