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

Abstract

Objective:The aim of this study was to evaluate, ex vivo, the precision of five electronic root canal length measurement devices (ERCLMDs) with different operating systems: the Root ZX, Mini Apex Locator, Propex II, iPex, and RomiApex A-15, and the possible influence of the positioning of the instrument tips short of the apical foramen.Material and Methods:Forty-two mandibular bicuspids had their real canal lengths (RL) previously determined. Electronic measurements were performed 1.0 mm short of the apical foramen (-1.0), followed by measurements at the apical foramen (0.0). The data resulting from the comparison of the ERCLMD measurements and the RL were evaluated by 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 for the 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% (RomiApex A-15), respectively, considering ±0.5 mm of tolerance. Regarding the mean discrepancies, no differences were observed at 0.0; however, in the measurements at -1.0, the iPex, a multi-frequency ERCLMD, had significantly more discrepant readings short of the apical foramen than the other devices, except for the Propex II, which had intermediate results. When the ERCLMDs measurements at -1.0 were compared with those at 0.0, the Propex II, iPex and RomiApex A-15 presented significantly higher discrepancies in their readings.Conclusions:Under the conditions of the present study, all the ERCLMDs provided acceptable measurements at the 0.0 position. However, at the -1.0 position, the ERCLMDs had a lower precision, with statistically significant differences for the Propex II, iPex, and RomiApex A-15.

Influence of the instrument used for cervical preflaring on the precision of 2 Eletronic Apex Locators

“…In order to be classified as accurate, the required difference between the real and the electronic measurement must be ≤ 0.5 mm; this method was considered to be highly accurate in previous studies 22,27 . According to the results obtained in this study, and also according to other similar studies, the tolerance range was adopted and allowed to observe that after cervical preparation the devices used were highly effective 21,27 .…”

“…The option to assess the accuracy of the EALs at major foramen level (0.0 mm) was based on studies that obtained satisfactory results using that limit, since the chances of obtaining diverging LRC measurements are higher as there is an increase in the distance between the tip of the file and this limit 12,22 . In order to avoid a distortion in the measurement, it is recommended to use the EAL until its display shows "APEX" or 0.0 mm.…”

“…For this reason, the material that is commonly used is 1% agar, saline solution, alginate, gelatin or sponge soaked in saline solution 10,24 . In this study, the teeth were embedded in alginate to perform the measurements, as this Protocol facilitates samples preparation, provides high degree of stability, and leads to accurate measurements 20,22 . Furthermore, it is reported to be the most reliable and reproducible method 24 .…”

“…Although numerous studies indicate an increase in the accuracy concerning the determination of the WL by different EALs 5,7,[22][23][24] , the fact that prior cervical preparation of root canals performed with different instruments might affect the accuracy of these devices has not yet been proved. Thus, this study was aimed at evaluating the influence of cervical preparation, using LA-Axxess (SybronEndo) and S1 and Sx ProTaper (Dentsply Maillefer), on the accuracy of Root ZX mini and Joypex 5.…”

Análise comparativa de diferentes métodos de odontometria

“…Vasconcelos et al36 que observaram em seu estudo que os LAEs Root ZX e Propex II fornecem medições aceitáveis na posição de 0,0. No entanto, ao posicionar as pontas dos dispositivos a 1,0 mm do forame apical, verificou-se que o LAE Propex sofreu uma perda significativa de precisão com diferenças estatisticamente significativas com relação ao Root ZX .…”