METHOD FOR TOOL PIECE REMOVAL FROM TOOTH ROOT CANAL AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2018 - IPC A61C19/00 

FIELD: medicine.

SUBSTANCE: method is implemented by insertion of an electrode device consisting of two electrodes isolated from each other of a shape providing, when introduced, a simultaneous contact of both electrodes with a metal fragment, into the root canal. Then, an electrical impulse is passed through a closed circuit formed by the first electrode, the metal fragment and the second electrode, with energy sufficient for contact welding of the fragment with the electrodes. In case of a successful attempt, the electrodes from the root canal are extracted together with the welded fragment. To obtain a strong connection of the electrodes with the metal fragment, electric activation of the microcontact welding is carried out by feeding a current monopulse of with energy of 0.45 J with a smooth increase in the current amplitude from zero to the maximum and pulse duration τ=9-10 ms. Electrical activation of the welding process is supplemented by mechanical activation of the microcontacts at the points of electrodes contact with the metal fragment due to the elastic properties of the electrodes in the electrode device. The welding current monopulse is formed in an oscillatory LC circuit consisting of a capacitor and a primary winding of the pulse transformer. To the secondary, lowering winding of which an electrode device is connected, consisting of two electrodes made of strips of a bimetallic plate - nickel-phosphorous bronze, possessing elastic properties. The electrodes are bonded together through a thin dielectric layer, in the end working part they are bent so that the angle between the nickel surfaces of the electrodes is ≈20°, and form a wedge-shaped gap. The tool fragment, falling into the gap between the nickel surfaces of the electrodes, closes the electric circuit for the microcontact welding process.

EFFECT: reduced impact of impulse voltage and thermal impact on tooth tissues.

10 dwg, 3 tbl