Comparing the accuracy of two electronic apex locators in the determination of working length and the detection of root perforations: An in vitro study

Aim: To determine the accuracy of two electronic apex locators in measuring working length and detecting the location of root perforations. Methodology: A total of 30 distal roots of extracted first maxillary molars were chosen. The actual working length was first measured. The electronic working length was obtained with Root ZX and Raypex 6. The differences between electronic working lengths and actual working length were calculated. Afterwards, the same roots were perforated artificially above the apical foramen. Both devices were utilized to locate perforations in the distal roots. Subsequently, the obtained measurements were compared. Intraoral environment was simulated employing a fixation device. Data were analysed using repeated measures ANOVA, paired sample t test, chi square, and Fisher exact tests. Statistical significance was considered at the 0.05 level. Results: There was no significant difference among electronic working lengths, measured with the two devices, and actual working length (p>0.05). The percentage of accuracy of electronic working lengths, measured by Root ZX and Raypex 6, was 85.7% and 90.9% respectively within a tolerance of ±0.5 mm (p>0.05). Moreover, the difference between the devices was significant with regard to the location of root perforations (p<0.05). Conclusions: Both electronic apex locators were able to determine canal length. Raypex 6 was more accurate than Root ZX in locating root perforations. *Correspondence to: Kaveh Nasiri, DDS, MSc (Endodontics), Department of Endodontics, Center for Operative Dentistry and Periodontology, University of Dental Medicine and Oral Health, Danube Private University, Krems, Austria, E-mail: DDS.Nasiri@web.de