The establishment of a correct working length is
one of the fundamental parameters for endodontic
success. Traditionally this has been determined
using radiography, but electronic apex locators
are increasingly being used. Electronic apex locators
reduce the number of radiographs required
and assist where radiographic methods create difficulty.
The use of an electronic apex locator in
combination with the radiograph is greater precision
in the determination of root canal length. The
aim of this paper is to review the electronic determination of the length of the root canal.