[Diagnosis of occlusal caries lesions using laser fluorescence measurements]

Recently, a device for detecting occlusal caries lesions (DIAGNOdent) has been introduced. The reproducibility and validity of this laser-fluorescence device were investigated. In the in vivo part of the study, 45 sites at the occlusal surfaces of permanent molar teeth in 13 patients were measured by 2 observers using 2 DIAGNOdent devices, one produced in 1998 and one in 1999. The interobserver reliability between both devices and both observers was established. In the in vitro part of the study, 49 permanent molars were measured by 2 observers using 2 DIAGNOdent devices. In addition, visual inspection was performed. The teeth were sectioned to measure the histological depth and area of the caries lesions. The reproducibility of both DIAGNOdent devices was high, and so was the interobserver reliability. The correlation between DIAGNOdent measurements and the actual depth of the caries lesions was lower than that of visual inspection. The correlation with the enamel part of the lesion exceeded that of the dentine part. It was concluded that the validity of the DIAGNOdent, expressed as the area under the Receiver Operating Characteristic (ROC) curve, was not statistically significantly different from that of visual inspection. Because of the high reproducibility, dental practitioners who wish to use the DIAGNOdent for monitoring caries lesions, this investigation indicates that an old device may be replaced by a new one, provided that the same tip will be used.