An In Vivo Comparison of Two Frequency –based Electronic Apex Locators

By Welk A, Baumgartner J, Marshall J

Date: 01/2003
Journal: JOE


Compare Root ZX (2 frequency) vs Endo Analyzer Model (EAM) 8005 (5 frequency)


Coronal ½ of clinical crowns removed-accessed and flared-k file used to make measurement in each canal with both EALs-alternated which EAL was used first, after second EAL length recorded the file was cemented in place with GI-teeth extracted, radiographed, viewed under dissecting scope-shaved apical 4mm of tooth along the long axis of the tooth until file could be seen-file distance to minor foramen measured.


  1. Mean distance from file to minor diameter was 1.03 mm with EAM and .19mm for ZX
  2. Minor diameter located in 90% with ZX and 34% with EAM

Clinical Significance:

Root ZX is more accurate than EAM –was able to locate the minor diameter 90% of the time and the EAM was 34%