Methods Based on Electrical Current

These include electrical conductance and electrical impedance, such as the CarieScan PRO system. With the understanding that dentin is more conductive than enamel, and that porous (lesioned) enamel is more conductive than sound enamel, measuring the electrical conductance of the tooth can detect demineralized sites in enamel, sites that have become porous (indicating a lesion), and cavities. Also, with the knowledge that every material has different electrical impedance determined by its molecular composition, it is theoretically possible to detect carious lesions because they have lower electrical impedance than sound tissue.

A recent study that compared results of the DIAGNOdent pen and the CarieScan Pro to ICDAS in both in vitro and in vivo conditions reported: “The in vivo results of ICDAS and DIAGNOdent pen were satisfactory and comparable to those obtained in vitro, with ICDAS performing better. The CarieScan PRO performed poorly under both conditions.”29 These results suggest that, although some of the diagnostic methods might provide some level of useful information, they should be used with caution. At present, the ICDAS criteria are the most clinically relevant approach available for accurate assessment of caries.