Electrical methods of apical constriction location

Abstract

Exact measurement of distance to the apical constriction during root filling of a damaged tooth is important for endodentists. Radiologic method employing X-rays is exact and visual. But it is slow process and exposes the patient to unnecessary X-ray radiation. It does not exclude the possibility of incorrect diagnosis. Electric methods have a competitive advantage. They are based on measurement of active or complex (active-capacitive) electric resistance between the electrode being in the tooth canal and, for example, the basic electrode attached to oral mucosa. Two electric current sources of different frequency are used for suppressing the measurement errors caused by the drastic change of resistance of dry or wet canal and by use of different liquids for canal processing. The apical constriction locator developed in Lithuania is analyzed in this paper.