Clinical Evaluation of the Accuracy of Raypex~ 5 Electronic Apex Locator

Objective: To assess the accuracy of Raypex 5 electronic apex locator in measuring root canal working length.Methods: 903 root canals of 342 teeth were randomly divided into two groups.Raypex 5 electronic apex locator were used to measure 458 root canal' working length in experimental group,while manual measurement were used to measure 445 root canals' working length in control group.We combined the radiograph to evaluate the accuracy of different methods in measuring root canal working length.Results: Within-2.00mm～-0.5mm from the apical foramen in radiograph,the accuracy of experimental group was 94.32%,higher than the control group(75.06%).The difference between electronic measuring methods and manual measuring methods was statistically significant(P0.01).Many factors,such as pulp vitality,bone resorption in periapical lesions,types of caries cavity,tooth position,dental morphology,the number of root canal don't have significant effect on measuring root canal working length by Raypex 5 electronic apex locator.Conclusion: Raypex 5 electronic apex locator is an accurate and reliable method in determination of root canal working length.It is better than manual measurement and is worth popularizing in clinics.