An improved model for teaching use of electronic apex locators.

AIM To develop a simple, practical and inexpensive model, which enables the use of electronic apex locators (EALs) during pre-clinical and continuing education. METHODOLOGY Extracted teeth were placed in a mould and embedded in acrylic resin. The resin was applied in two consecutive steps to form a cavity around the root apices. A closable plastic tube serves as a valve, and a steel wire connects to the EAL. RESULTS With its semi-closed reservoir for conductive fluids surrounding the root apices, the new model enables working length measurements of root canals using EALs. CONCLUSIONS The model simulates the clinical situation for endodontic teaching purposes, as it allows working length determination of root canals as recommended. The measuring results of the EAL can be verified by radiography. At the same time, the roots are not directly visible and accessible to the user, allowing a precise evaluation and grading of the treatment.