Clinical performance of DIAGnodent in the detection of secondary carious lesions

The diagnostic value of DIAGNOdent in detecting primary occlusal caries has been investigated in many studies, although its use in in vivo detection of secondary caries remains unclear. The aim of this study was to investigate the ability of DIAGNOdent in in vivo detection of secondary caries on teeth with amalgam restorations. The material comprised 51 posterior teeth restored with amalgam material. Bitewing radiographs were taken of all teeth, in accordance with the standard clinical protocol, and analysed by five observers with respect to secondary caries. The restoration margins of each tooth were carefully scanned with DIAGNOdent and the site of the highest reading and its value were registered in a digital picture. The color (stained/unstained) of the restoration margins was also documented. The restoration material was removed and all cavities were examined carefully by two observers together, both visually and by probe. The results showed that the sensitivity and specificity of DIAGNOdent and conventional radiography in detecting secondary caries were 0.60/0.81 and 0.56/0.92, respectively. For DIAGNOdent, 100% of the teeth in the false-positive fraction had stains. Regarding receiver operating characteristic analyses, the Az values were 0.78 and 0.69 for DIAGNOdent and radiography, respectively. We conclude that DIAGNOdent may be used only as an adjunct to conventional methods in detecting secondary caries on teeth with amalgam restorations.