In vitro evaluation of an audiometric device in locating the apical foramen of teeth.

A new audiometric device to determine the location of the apical foramen of teeth undergoing endodontic treatment according to "the relative value method" was tested in in vitro experiments. In 96.5% of the 350 human teeth used in the experiment, the location of the apical foramen was determined within acceptable limits (0-0.5 mm). In 60 teeth, where the measurements were based on an intermittent audio signal, a point about 1 mm short of the apical foramen was located. The results were considered promising and a clinical evaluation of the device will be carried out.