In vivo measurement accuracy in vital and necrotic canals with the Endex apex locator

By Mayeda D, Simon J, Aimer D, Finley K

Date: 01/1993
Journal: JOE


  • Purpose: To evaluate, in vivo, the measurement accuracy in vital and necrotic canals by means of the Endex (Osada Electric Co., Los Angeles, CA) apex locator.
  • Materials/Methods:

  • N=33 teeth destined for extraction (single-rooted maxillary or mandibular teeth with mature apices).
  • RGs were taken to determine whether or not a PAL and/or resorption is present.
  • Teeth were tested using an Analytic Technology pulp tester, a carbon dioxide ice pencil, percussion, and palpation.
  • 17 teeth were determined to be vital and 16 were necrotic.
  • L.A, R.D and access cavity
  • Canals were irrigated using 5.25% sodium hypochlorite and were not dried prior to insertion of the measurement file.
  • A file (between a #15 and a #35) was inserted within 2 to 3 mm of the radiographic apex.
  • Once the Endex indicated the apex, another RG was taken.
  • Self-curing composite was injected into the remaining canal space, the tooth was extracted and stored in formalin.
  • Most highlighted Results:

  • All measurements were made from the major diameter because it was reproducible and consistent.
  • Vital Vs. necrotic cases (Table)
  • No significant difference between the means of the vital and the necrotic cases.

Clinical significance:

Each operator should correlate his own radiographic and clinical findings with the analog dial readings on the instrument to determine exactly where the apical constriction is.