Résumé
In order to evaluate the accuracy of RayPex5 apex locator in measuring root canal working length in clinical practice and to analyze the possible factor resulting in deviation, the working length of total 211 root canals were measured by handing method and electronic method respectively. The exact working length of those root canals were determined by X-ray method. The accuracy rate of electronic method and handing method was 96.21% and 78.2% respectively, with significant difference(P<0.001). The accuracy rate of front teeth group and molar group measured by electronic method was 100% and 92.5% respectively, with significant difference(P<0.05), while the apical paradentitis group and the apical non-paradentitis group, the front teeth group and the premolar group, and the premolar group and the molar group didn' t differ from each other, respectively. The study showed that the accuracy rate of electronic method was high for determining root canal working length, and Raypex 5 apex locator could define apical seat to measure root canal working length accurately.
Résumé
Objective:To study the effects of file tip size on the accuracy of Root ZX apex locator during electronic measurements in enlarged root canals.Methods: Forty premolars mounted in 20 g/L agar were used.First,the canals were instrumented using size 15-40 K-files with a size 40 as the master apical file(MAF).Second,the canals were enlarged using 45-60 K-files with the step-back way and 60 K-file as the MAF.In each step,the length was measured with a Root ZX using small and large tip size files.Results: File tip size and the degree of root canals enlarged both had a significant influence on the measurement,the difference was 0.22 mm.Conclusion: The measured working length with smaller size files become shorter when the root canals are enlarged.A file size comparable to the root canals should be used with root length measurement before root canal fillings.
Résumé
Objective:To observe the accuracy of electronic method(EM), handing method(HM) and X-raying method(X-RM) in measuring root canal working length. Methods:Total 31 root canal in vivo were measured with HM, X-RM and EM(by the electronic apical locators-Root ZX and Raypex-5 respectively), and the data were compared with the actual root canal working lengths which were obtained from the sectional view's constrictions of the extracted teeth by magnifying glass. Results:Accuracy of working length measured by Raypex-5 was 93.55%, Root ZX was 87.10%, HM was 35.48%, and X-RM was 48.39%. Significantly statistical differences (P