Intelligent Electrometric Device for Dental Caries Diagnosis

Abstract

The article deals with the development of a medical device for high-precision measurement and automatic diagnosis of dental caries stage. The analysis of the composition and characteristics of tooth hard tissues, being the cause of caries and its development, is given. It has been established that the main cause of the carious process is the attack of acid-forming bacteria on tooth enamel. It is shown that the most promising method for caries diagnosis is the electrometric method, which consists in measuring electrical conductivity of the tooth hard tissue electrolyte. Conventional devices for the electrometric method implementation are described, using the direct current through the biological tissue of the tooth, but not taking into account the electrochemical features of the current flow. An electrochemical interpretation of the current flow through biological tissues and two electrodes with a polarity switch of these electrodes was performed, which makes it possible to exclude the effect of polarization of biological tissue and electrodes both for teeth in vivo and in vitro. An equivalent diagram of the current flow through the biological tissue is given, which value can reveal the stage of the carious process: intact enamel, pre-carious state, initial, superficial, medium and deep caries. The use of two current-carrying electrodes for measuring the electrical conductivity of biological tissues is considered: an active electrode made of stainless steel using a 10% solution of CaCl2 and a passive electrode also made of stainless steel and using an electrolyte of the biological tissue of a tooth (simulated by a 0.9% solution of NaCl). A comparative assessment of the tooth biological tissue electrolyte electrical conductivity and electrical conductivity of the active and passive electrode electrolytes was performed to assess the error of the electrometric method. A high-precision intelligent electrometric device (protected by a patent for an invention) has been developed, which allows automatic carious process stage determination by the value of the tooth biological tissue electrical conductivity; the operation of this device is described.