Materials and Methods
When measurement with apex locator is conducted during endodontic treatment of the root canal, files and needles used for the treatment are commonly used as active electrodes too. In this experiment Miller-Donalds (M-D) needle and Kerr file nr. 35 were used as active electrodes. The diameter of the tip of both electrodes is 0,35 mm, the Miller-Donalds needle tip is flat, and it’s