Occlusal caries diagnosis: an in vitro histological validation of the electronic caries monitor (ECM) and other methods

Objectives: The aim of this in vitro study was to validate the use of the Electronic Caries Monitor (ECM) for the detection of enamel and dentinal caries on the occlusal surfaces of posterior teeth, and to compare it with visual examination, fibre-optic transillumination, conventional and digital bitewing radiography. Methods: One-hundred and three extracted posterior permanent teeth with no apparent occlusal cavitation were selected and examined using each system. Thirty teeth were re-examined with each system to assess repeatability. Each tooth was then serially sectioned and examined histologically for occlusal caries. Results: The occlusal surfaces of 25 teeth had caries in enamel and 37 had dentinal carious lesions. The sensitivity and specificity of the ECM were 0.78 and 0.80 for the diagnosis of occlusal dentinal lesions (cut-off=0.391) and 0.65 and 0.73 for enamel lesions (cut-off =0.501). The weighted kappa value for repeatability of the ECM was 0.68. Of the other diagnostic systems, visual examination provided the best combination of sensitivity and specificity, 0.24 and 0.97 for dentinal caries and 0.60 and 0.73 for enamel caries, respectively. Conclusion: The ECM was the most accurate diagnostic tool for the in vitro diagnosis of early, non-cavitated occlusal lesions on posterior teeth.