Impedance spectroscopy for monitoring sound teeth and carious lesions

In this study, impedance spectroscopy measurements are proposed as a non-invasive and fast approach for assessing dental diseases. The possibility of employing impedance measurements in caries detection relies on the characteristic loss of mineral due to the caries process, leading to an increased porosity in the tooth structure, which results in a higher liquid content than healthy tissue. Impedance measurement detects this variation by evidencing a different behavior and a shift in the phase characteristics. Some healthy teeth and carious lesions were analyzed and impedance spectra were recorded in-vitro by means of a two-electrode measuring approach, which could be feasible, once optimised, also for in-vivo measurements. The preliminary obtained results evidenced a shift from the resistive behaviour to the capacitive-like which happens at different frequencies if the measurement is performed on the healthy tooth or on a damaged area, allowing an easy discrimination between healthy teeth and teeth affected by caries.