Methods Based on Electrical Current

These include electrical conductance and electrical impedance. 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 possible to detect carious lesions because they have a lower electrical impedance than sound tissue.