Endodontic apex locators or electronic apex locaters are used in endodontics to measure the length of the root canal via the position of the apical foramen. As technology improves for endodontic apex locators, an increase in accuracy makes these devices more popular. Many electronic apex locators can give accurate measurements despite fluid conductive like saliva, blood or irrigant. Accuracy can vary between 80% and 96%, which is better than a radiograph. When the maximum length of the root canal is reached, the endodontic apex locator will signal via beep, buzz, flashing light or all of the above. Some show an image of the tooth with the root canal measurements on a monitor. When choosing an endodontic apex locator, be sure that an accurate root canal measurement can be attained regardless of fluid conductive, this will give you a more accurate reading.