In vitro comparison of two photostimulable phosphor plate systems for early detection of occlusal dentin caries with and without a sharpening filter

Background. Dental caries is the most important reason for tooth loss. Clinical examination is the most commonly used technique for occlusal caries diagnosis. Diagnostic power of digital systems is a matter of controversy in this field. The aim of the present study was to determine the diagnostic accuracy of two photostimulable phosphor plate (PSP) systems for early occlusal dentin caries in vitro. Methods. A total of 69 extracted molar and premolar teeth were used in this study. The teeth were mounted in triple blocks and standard radiographs were taken by the Digora and Acteon digital radiographic systems. The original and enhanced-filter 1 radiographs were evaluated by two experienced observers twice at an interval of two weeks and dentin caries were recorded in Tables prepared for the purpose of the study. Then the teeth were sectioned in a buccolingual direction and evaluated under a stereomicroscope. The observers’ reports were compared with microscopic findings as the gold standard. SPSS 23 was used to calculate kappa coefficient, sensitivity, specificity and the area under the ROC curve (AUC). Statistical significance was set at P<0.05. Results. The internal and the external agreement in both imaging systems was good to excellent. The means of sensitivity, specificity and AUC, in the Acteon system were 34.1, 92.9 and 0.674, with 30.8, 94.8, 0.659, respectively, in the Digora system. Conclusion. Accuracy of early occlusal caries diagnosis was poor on both systems and no significant difference was observed between the two systems at 95% confidence interval. Although the AUC was a little higher in the original images, there was no significant difference between them; however, due to their high specificity, they can prevent unnecessary treatments in the clinic.