Comparison between radiographic films and the Digora digital system in the diagnosis of approximal dentinal caries in primary molars

Abstract

This study evaluated the diagnostic performance of the Agfa M2 and Ektaspeed Plus dental films and the Digora digital system. The material comprised 37 extracted primary molars radiographed with 50, 70 and 90 kV. The images of 41 approximal surfaces were examined under standardized conditions. Five imaging modes (0.5 X, 1 X, 2 X, "Negative" and 3D) available in the software of the digital system, were used. The teeth were sectioned and observed under a stereomicroscope (40 X). The data were analysed for sensitivity, specificity, accuracy and unweighted kappa. Ektaspeed plus exposed to 50 kV obtained the highest sensitivity, accuracy and kappa values. The specificity values of the films were comparable. Digora presented the highest values of sensitivity when the "Negative" mode was used. The majority of the reduced images (0.5 X) revealed the highest specificity. The average accuracy values of the digital system were very similar. Unweighted kappa revealed that all digital image modes established good agreement. The sensitivity values of the digital system were higher than that of the conventional films, but films revealed higher values of specificity. The average accuracy values of Digora were higher than that of the films, for all kilovoltages. Except for Ektaspeed Plus at 50 kV, the films did not reach the kappa values of Digora in the diagnosis of dentinal caries. Cohens kappa revealed good intra-examiner reliability (0.758). It was demonstrated that the digital system is comparable to the conventional radiographic method in the diagnosis of approximal dentinal caries in primary molars.