Use of an electronic apex locator in the treatment of teeth with incomplete root formation.

An electronic apex locator was used to determine length and control apical bridge formation in the treatment of teeth with incomplete root formation. Measurements were taken in 10 teeth in which apexification therapy had just started and in 11 teeth where the formation of the apical barrier was considered to be complete. In the beginning of the apexification therapy, when the apical foramen was still open, endometric measurements gave incorrect results in all instances. After apical closure had occurred and definite obturation of the root canal seemed possible, the apex locator in all teeth gave correct results and complete agreement was obtained between the radiographs and the electronic tests. Even in teeth in which complete apical closure could not be obtained, the results of electronic measurements were correct. Electronic apex locators may be used as auxilliary devices in controlling apical hard tissue closure in the treatment of teeth with incomplete root formation.