The ability of two apex locators to locate the apical foramen: an in vitro study.

The objective of this study was to compare the accuracy of the Root-ZX and Novapex electronic apex locators (EALs) in locating the apical foramen. Forty extracted human teeth were used. The coronal portion of each canal was flared using Gates Glidden drill. Canals were irrigated with 2.5% sodium hypochlorite. The actual length (AL) and electronic length (EL) measurements were made on each specimen separately with both devices with an aid of a K-type file. The results obtained with each EAL were compared with the corresponding control length. The statistical analysis of the results showed EAL reliability in detecting the apical foramen to 89.7% for the Root-ZX and 82.1% for the Novapex, taking the tolerance of +/-0.5 mm into account. A paired sample t test showed that there was no statistically significant difference between the accuracy of the devices (p = 0.4305). The results of this study indicate that the Root-ZX and Novapex are useful and accurate devices for the apical foramen location.