Clinical Quantification of Occlusal Caries: In vivo Study

Objective: The purpose of this study was to assess the correlation between DIAGNOdent™ readings and the clinical extension of occlusal caries in vivo. Methods: Sixty class I carious lesions (56 molars; 5 premolars) planned for restoration were included in the study. Preoperative radiographic evaluation was done. Visual and tactile examinations were made by two experienced clinicians using visual (Ekstrand) and tactile (Radike) criteria. Carious sites were scanned with the DIAGNOdent before and after cleaning with the Prophyflex2™. Conservative caries removal was done; sequential intra-oral photographs were taken during operative dissection of the lesions; clinical lesion depth was measured with a periodontal probe marked in mm. A PVS impression was made of the completed preparation and the volume of tissue removed was calculated from the weight of the impression material. Teeth were restored with conventional composite. The specificity and sensitivity of the device were calculated at different cut-off values. Pearson's correlation was used to assess the validity of the device. Results: Caries existed only in enamel in 13 teeth and extended to dentin in 47 teeth. The DIAGNOdent readings ranged from 14 to 99. The depth of cavities deviated from 1.5 to 5 mm, with an average of 3.27 mm. The cut-off points for enamel and dentinal caries were calculated by plotting the DIAGNOdent values as functions of cavity depth after caries removal. The most appropriate cut-off point to diagnose dentinal caries was between 35 and 38, considering both sensitivity and specificity. Conclusions: The correlation between DIAGNOdent measurements before and after cleaning was 0.52 and 0.47 respectively for the actual depth of the lesion, and 0.47 and 0.44 respectively for the volume of the lesions. The increase in DIAGNOdent values were more strongly correlated to the increase in visual scores (0.55) than the tactile scores (0.37).