An in vitro comparison of the ability of fibre-optic transillumination, visual inspection and radiographs to detect occlusal caries and evaluate lesion depth.

The aim of this study was to compare the performance of fibre-optic transillumination (FOTI), visual inspection and bite-wing radiographs to detect occlusal caries and estimate the lesion depth. Fifty-nine extracted molars were assessed using FOTI and visual examination by 4 trained examiners and 1 examiner evaluated the bite-wing radiographs. Histological validation was performed using 250-microm sections examined with a stereomicroscope. For the three methods, the correlation between the lesion depth and the histological scores varied from 0.65 to 0.73. For dentinal caries detection, the areas under ROC curves ranged from 0.83 to 0.87. The radiographic method was poor at detecting lesions confined to enamel. FOTI, visual inspection and radiographs showed a good correlation with the histology but had difficulty in distinguishing lesions located deep in enamel or in the outer third of dentine. FOTI was shown to be as accurate as a detailed visual inspection in detecting occlusal caries.