Effects of a PVC sealwrap on the performance of DIAGNOdent

Objectives: The aim of this study was to evaluate the influence of a transparent PVC sealwrap, as barrier protection, on the DIAGNOdent (DD) performance in occlusal sites of primary molars. Methods: 21 primary molars were analysed in five different conditions: (1) DD calibrated without PVC sealwrap in its tip, (2) DD calibrated with one layer of the sealwrap, (3) DD calibrated with 3 layers of the sealwrap, (4) DD calibrated without sealwrap and samples analyzed with one layer of this film on its tip, (5) DD calibrated without sealwrap and samples analyzed with three layers of the film on its tip. Histological examination was obtained with a stereoscopic loupe. We compared the DD values, as well as accuracy and area under ROC curve for dentine lesions . Using a cut-off of 13, accuracy was calculated (McNemar test for comparison). Results: There was significant statistically difference between measurement values (p<0.05) between groups 1 and 5; 1 and 3; 2 and 5. Accuracy of 0.81 was obtained for groups 1, 2 and 3 and of 0.73 and 0.71 for groups 4 and 5, respectively, but there was not significant difference among these values. The area under ROC curve showed significant difference between groups 2 and 4. Conclusion: It was concluded that to improve DD performance, the tip of the device must be calibrated in the same condition of those in which the measurements will be achieved. Conditions that uses 3 layers of the PVC sealwrap must be avoided in order to don't underestimate caries lesions in clinic situations.