Study of Impedance Frequency Dependences of Healthy and Depulpated Teeth

The most common dentistry methods for depulped teeth identification is electrodontometry and radiography, which cause the patient to feel uncomfortable. One of the promising methods for determining depulpated teeth is a method based on measuring the tooth tissues impedance. The paper presents the results of in vitro studies of teeth impedance frequency dependence before and after their depulpation. Depulpation was performed according to the standard procedure using gutta-percha pins and a sealer. Experimental studies were carried out in the laboratory of the St. Petersburg State Electrotechnical University “LETI” using the immitance meter E7-20 and specially designed measuring sensors. The experimental results obtained on 20 samples in vitro showed that the impedance values of depulpated teeth are more than 30% higher than its values for healthy teeth in frequency range from 25 Hz up to 100 kHz. These results were confirmed by studies on a small sample in vivo.