Authors : C.H.R. Stavrianos , S.T. Vladimirov , L. Vasiliadis , I. Stavrianou , I. Panayotov and P. Pamporakis
Abstract: The purpose of this study was to evaluate in vitro the accuracy of 4 different Electronic Apex Locators (EALs) for determining the Working Length (WL) of endodontically retreated teeth. Forty human single rooted teeth with mature apices, recently extracted due to periodontal disease or orthodontic reasons, retained in thymole solution 1%, were used for this study. The WL was established by subtracting 0.5 mm from the actual canal length. The root canal systems were instrumented and disinfected and then divided in 2 groups, the control group (n = 8) and the experimental group (n = 32). The root canals of the experimental group were obdurated using vertically compacted gutta-percha with AH 26 sealer. In a wax sheet of 2 mm thickness, 40 holes were made and both control and experimental groups were inserted into them up to their neck while a box containing alginate powder mixed with sodium hypochlorite solution 1% was prepared to simulate the periapical tissues. For the Electronically Determined Length (EDL) four EALs were used: Dentaport ZX (J. Morita Co. Kyoto, Japan), RayPex 5 (VDW GmbH, Germany), Endo Master (Electro Medical Systems SA, Switzerland) and Bingo-1020 (Dent Corp research and development U.S.A.). During canal length measurement, the canal was flushed with 2.5% NaOCL. The measurements were made with the help of a K-file No 20, inserted into the root canal. The difference between AL and EDL was calculated and reported for each tooth. In the control group, the EDLs by Dentaport ZX, RayPex 5 and Endo Master were all 8 (100%) within AL�0.5 mm, while the EDLs of Bingo 1020 were within AL�1.0 mm. In the experimental group we had a variety of prices but the majority of the EDLs determined by the 4 EALs were within AL�0.5 mm. The EALs Dentaport ZX and Endo Master were more accurate than the other two EALs in determining WL in retreated teeth. However, the RayPex 5 and the Bingo 1020 were also reliable in the majority of cases.
C.H.R. Stavrianos , S.T. Vladimirov , L. Vasiliadis , I. Stavrianou , I. Panayotov and P. Pamporakis , 2008. In vitro Evaluation of the Precision of Four Different Electronic Apex Locators in Determining the Working Length of Teeth after Removing Root Canal Obturation Materials. Research Journal of Medical Sciences, 2: 282-286.