Accuracy of five electronic foramen locators with different operating systems: an ex vivo study

Objective:

The aim of this study was to evaluate, ex vivo, the precision offive electronic root canal length measurement devices (ERCLMDs) with differentoperating systems: the Root ZX, Mini Apex Locator, Propex II, iPex, and RomiApexA-15, and the possible influence of the positioning of the instrument tips shortof the apical foramen.

Material and Methods:

Forty-two mandibular bicuspids had their real canal lengths (RL) previouslydetermined. Electronic measurements were performed 1.0 mm short of the apicalforamen (-1.0), followed by measurements at the apical foramen (0.0). The dataresulting from the comparison of the ERCLMD measurements and the RL were evaluatedby the Wilcoxon and Friedman tests at a significance level of 5%.

Results:

Considering the measurements performed at 0.0 and -1.0, the precision rates forthe ERCLMDs were: 73.5% and 47.1% (Root ZX), 73.5% and 55.9% (Mini Apex Locator),67.6% and 41.1% (Propex II), 61.7% and 44.1% (iPex), and 79.4% and 44.1% (RomiApexA-15), respectively, considering ±0.5 mm of tolerance. Regarding the meandiscrepancies, no differences were observed at 0.0; however, in the measurementsat -1.0, the iPex, a multi-frequency ERCLMD, had significantly more discrepantreadings short of the apical foramen than the other devices, except for the PropexII, which had intermediate results. When the ERCLMDs measurements at -1.0 werecompared with those at 0.0, the Propex II, iPex and RomiApex A-15 presentedsignificantly higher discrepancies in their readings.

Conclusions:

Under the conditions of the present study, all the ERCLMDs provided acceptablemeasurements at the 0.0 position. However, at the -1.0 position, the ERCLMDs had alower precision, with statistically significant differences for the Propex II,iPex, and RomiApex A-15.