[The evaluation of the ability of Apex D.S.P. to determine the length of root canal. In vitro study]

Abstract

Introduction: Precise determination of an individual root canal length is one of the main factors affecting the results of endodontic treatment. There are a few ways to determine an individual root canal length. Two of them, radiologic and endometric are in common use. The disadvantage of using the first method is that it is only approximate determination of the apical foramen that can cause incorrect preparation and filling of root canals. Alternative to radiologic method is an endodontic method in which resistance apex locators can be applied or the next generation devices called frequency apex locators, which include Apex D.S.P. The aim of the study was to examine the accuracy of working length measurements of root canals, as determined using Apex D.S.P., new generation apex locator, with reference to the real canal length.

Material and methods: A total of 102 canals were examined in 73 extracted human teeth with mature apices. The crown was sectioned with a diamond disc to allow an access to the root canal. After removing the contents of canals, the actual root canal length was measured by inserting the file into the root canal until the file tip was just visible at the level of the apical foramen. Then the teeth were placed in contact with an alginate impression material to simulate the periodontium. Electronic measurement was achieved using the Apex D.S.P. Measurements were taken until the red diode lights and then after the last green diode lights (0.5 mark). The differences between the actual root canal lengths and the measurement results were noted. All lengths of files were measured using endodontic ruler. The chi2 test was used to analyse statistically.

Results: The Apex D.S.P. located the apical constriction accurately within +/- 0.5 mm in 88.2% of canals. Statistical analysis has shown that more accurate results were reached when the file was introduced until the last green diode lit (p < 0.05).

Conclusions: The latest generation of apex locators provides an accurate and useful assistance for the determination of the root canal length.