Effect of Using Electronic Apex Locators on Selected Endodontic Treatment Parameters

By Fouad A, Reid L

Date: 01/2000
Journal: JOE


Purpose: To determine the effect of using electronic apex locators (EALs) on the number of radiographs taken and the adequacy in length of the final obturation

N= 36 teeth/56 canals.                               

 Exclusion: cases where no electronic measurement could be obtained


  • The WL obtained by the authors, using both a preoperative standardized radiograph and an EALs
  • The students asked to take a WL radiograph based on one of the estimates (EALs or RG); randomly and blindly.
  • Once treatment was completed, the total number of radiographs was counted.
  • The number of acceptable cases (0 to 2 mm short of the apex) or unacceptable obturation was blindly registered.

Most highlighted Results: 

1.Number of radiographs was less in EAL than radiographic group (not significant)

2.The mean number of radiographs taken of the anterior or premolar was 3.18, whereas in the molars 3.91, (significant) FIG1

3.An EAL estimate of the WL improved length quality of the final obturation (1.25 mm short), compared with a radiographic estimate (was 1.64 mm short)  (significant ). Table 2

4.EAL measurements were not statistically different from FWL. However, the RG estimates were statistically different from both the EAL estimates and the FWL . FIG2


Clinical significance

Initial electronic estimate reduced the number of radiographs taken for anterior or premolar teeth by about one film and improves the length of obturation.