engleski

The influence of excitation current on the root canal length measurement

Root canal length measurement was simulated by placing the tip of the active electrode (Kerr file or Miller-Donalds needle) on the gingiva and measuring the impedance between the active electrode and large area electrode fixed on the lip. The impedance was measured for the series of voltage excitation amplitudes at the frequencies in range 20 Hz&#8211 ; ; 1 MHz. It has been shown that measured values of impedance tend to decline when current density higher than critical one is applied. This matches with the same measurements performed on the electrode/electrolyte interface, but critical values of current density are about 10 times lower for measurement in electrolyte. In the construction of electronic apex locator it is important to ensure that current density is lower than critical one for every needle used.

apex location; current density; endodontics; bioimpedance; electrodes

nije evidentirano