New Practical Model of the Division Method Electronic Root Canal Length Measuring Device

Abstract

  The commercialized model of the division method electronic root canal length measuring device, which simultaneously measures two impedances of a canal at two frequencies and computes the quotient of two impedance values, has been developed.

  The characteristics of this device were as follows :

  1. The meter value of the device was hardly affected by the electric conditions of the canal, but it considerably changed near apical constriction.

  2. The relationship between the meter value and the location of the file tip in the canal became more linear by the correction of the quotient using the conversion table on the microcomputer of the the device.

  3. Without any adjustment of the device, an accurate electronic measurement of the root canal length was performed by the device.