Inter-Institutional PhD Program, State University of Montes Claros, Montes Claros, MG, Brazil.
J Appl Oral Sci. 2012 Sep-Oct;20(5):538-43. doi: 10.1590/s1678-77572012000500008.
This ex vivo study evaluated the effect of pre-flaring and file size on the accuracy of the Root ZX and Novapex electronic apex locators (EALs).
The actual working length (WL) was set 1 mm short of the apical foramen in the palatal root canals of 24 extracted maxillary molars. The teeth were embedded in an alginate mold, and two examiners performed the electronic measurements using #10, #15, and #20 K-files. The files were inserted into the root canals until the "0.0" or "APEX" signals were observed on the LED or display screens for the Novapex and Root ZX, respectively, retracting to the 1.0 mark. The measurements were repeated after the preflaring using the S1 and SX Pro-Taper instruments. Two measurements were performed for each condition and the means were used. Intra-class correlation coefficients (ICCs) were calculated to verify the intra- and inter-examiner agreement. The mean differences between the WL and electronic length values were analyzed by the three-way ANOVA test (p<0.05).
ICCs were high (>0.8) and the results demonstrated a similar accuracy for both EALs (p>0.05). Statistically significant accurate measurements were verified in the pre-flared canals, except for the Novapex using a #20 K-file.
The tested EALs showed acceptable accuracy, whereas the pre-flaring procedure revealed a more significant effect than the used file size.
本离体研究评估了预扩口和锉型号对 Root ZX 和 Novapex 电子根尖定位仪（EAL）准确性的影响。
在 24 颗上颌磨牙腭侧根管中，将实际工作长度（WL）设置为比根尖孔短 1mm。牙齿嵌入藻酸盐模具中，两名检查者使用 #10、#15 和 #20 K 锉进行电子测量。将锉插入根管，直到 Novapex 和 Root ZX 的 LED 或显示屏上分别观察到“0.0”或“APEX”信号，然后回缩至 1.0 标记。在预扩口后使用 S1 和 SX Pro-Taper 器械重复测量。每种情况下进行两次测量，取平均值。计算组内相关系数（ICC）以验证检查者内和检查者间的一致性。使用三因素方差分析（p<0.05）分析 WL 和电子长度值之间的平均差异。
ICC 较高（>0.8），结果表明两种 EAL 的准确性相似（p>0.05）。在预扩口的根管中验证了准确的测量，除了使用 #20 K 锉的 Novapex。
测试的 EAL 显示出可接受的准确性，而预扩口程序的影响大于使用的锉型号。
