Ex vivo evaluation of the accuracy of four electronic foraminal locators during endodontic retreatment.

The present study aimed to evaluate the accuracy of four different Electronic Foraminal Locators (EFLs): Root ZX II (J. Morita, Tokyo, Japan), RomiApex A15 (Romidan, Kiryat-Ono, Israel), FinePex (Schuster, Porto Alegre, Brazil) and VDW Gold (VDW, Munich, Germany), in determining root length during endodontic retreatment steps. Twenty-seven human unirooted teeth had their crowns sectioned to standardize the teeth to 17 mm. The actual tooth length was visualized with an operating microscope and a #15 file juxtaposed to the apical foramen. Teeth were instrumented with files R25 and R40, and at the end of each instrumentation, measurements of root canal lengths were made with files #25 and #40. Then, the teeth had their root canals filled with standardized Gutta-Percha R40 cones and Endofill cement, and after seven days, they were uncovered with R25 and R40 files, respectively. New measurements were made with #25 and #40 files between the uncovering with each file. The data were statistically analyzed by ANOVA and Chi-square tests, considered significant when P<0.05. All devices tended to under-measurement when the obturating material was partially removed with the R25 file. When the canals were uncovered with the R40 instrument, the effectiveness of the appliances increased significantly (P<0.05). At 0.40 mm diameter, the mean accuracy of the Romiapex A15 appliance was statistically lower than the other EFLs (P<0.001), showing a tendency to over-measurement. In conclusion, all the tested appliances showed similar efficacy when acceptable limits were observed. The permanence of the remaining filling material in the apical third influenced the accuracy and efficacy of EFLs in endodontic retreatment cases. Key words:Endodontics, odontometry, apical foramen.

Ex vivo evaluation of the accuracy of four electronic foraminal locators.

Background: To evaluate the accuracy of four different Electronic Foraminal Locators (EFLs): Root ZX II (J. Morita, Tokyo, Japan), Romiapex A15 (Romidan, Kiryat-Ono, Israel), FinePex (Schuster, Porto Alegre, Brazil), and VDW Gold (VDW, Munich, Germany), in determining root canal length. Material and Methods: Twenty-seven human single-rooted teeth had their crowns sectioned at the cementoenamel junction, and the actual length of the tooth was obtained by visualizing with an operative microscope a #15 file placed adjacent to the apical foramen. The teeth were instrumented with R25 and R40 files, and at the end of each instrumentation, measurements of the lengths of the root canals were made with #25 and #40 files. The data were statistically analyzed by ANOVA and chi-square tests and were considered significant when P<0.05. All devices showed a tendency to underestimate measurements by 0.25 mm diameter. Results: The mean accuracy of the Root ZX II appliance was statistically lower than the other EFLs (P<0.001). For the 0.40 mm diameter, the mean accuracy of the Romiapex A15 appliance was statistically higher than the other LEFs (P<0.001). However, when the diameter was 0.40 mm, only the Romiapex A15 device tended to overmeasure. Regarding the acceptable limits of variation, it was observed that the devices showed similar efficiency in determining odontometry (P>0.05), both with diameters of 0.25 mm and 0.40 mm. Conclusions: It was concluded that the devices presented similar and adequate efficacy when observing the limits of acceptable measurements. It was observed that increasing the apical diameter did not influence the accuracy of EFLs in determining root canal lengths. Key words:Endodontics, working length, electronic foraminal locators, endodontic treatment.