This product roundup features several of the top apex locators available today.
An important part of endodontic procedures, apex locators are used to determine the position of the apical constriction and the length of the root canal. This measurement helps clinicians prepare a patient for root canal therapy by determining how far instruments should advance within the canal and at what point the preparation and filling should stop. It is also useful during the root canal procedure to help clinicians avoid root perforation, which can lead to a variety of short-term and long-term complications.
The principle behind apex locators is relatively simple. Because the apex has a specific resistance to electrical current, its location can be measured using 2 electrodes—1 clipped to the patient’s lip and 1 attached to an endodontic file. When the tip of the file meets the periodontal tissue, the 3 elements form a complete electric circuit. This causes resistance to decrease markedly, and the current suddenly begins to flow. Many apex locators mark this event with an audio signal or a device readout.
However, the first generation of electronic apex locators functioned quite differently. Instead of forming a closed circuit like modern devices, the original units operated on the direct current principle. The issue with these devices was that conductive fluids such as hemorrhage, exudate, or irrigant in the canal would permit current flow and therefore, would give a false reading.
Newer devices circumvented this by using the alternating current of 2 frequencies; these measure and compare 2 electrical impedances that change as the file moves apically. The benefit is that these devices are much less affected by fluid conductive media in the canal. The resulting locators are said to achieve 80% to 96% accuracy, which has been shown to be more accurate than radiographs.
Here, we present several apex locators the industry offers.
NEO
Measuring 46 mm × 43 mm × 16 mm, roughly the size of a smartwatch, the lightweight NEO is said to be the world’s smallest apex locator. Designed by a dentist, it can clip onto an included finger ruler, bib, or watchband, always keeping the device in your field of view. The NEO utilizes 3 separate bands of impedance to produce fast, accurate readouts. It is said to be tested at 97.5% accuracy, and its touchscreen display works even with gloved fingers.
A torque- and speed-controlled endodontic motor with a real-time apex locator, the EndoPilot features state-of-the-art technology designed to ensure efficient preparation of the root canal and patient safety. The integrated apex locator determines the real-time file position during treatment by transmitting a signal from a contra-angle handpiece and displaying the location of the file relative to the apex. The handpiece is fully insulated, which is said to eliminate electrical apex location errors. Its touch display allows users to easily set the depth of preparation relative to the apex. It features a preprogrammed file library containing commonly used file systems.
A lightweight, compact device, the EndoSync A.I. features automatic calibration, a memory bar, audible warnings, and a large LCD screen. It accurately determines the file’s location in a variety of canal conditions with no interference from the presence of blood, electrolytes, saline, or irrigants in the canal. EndoSync automatically calibrates to meet canal conditions during treatment, including changes in temperature and moisture.
This device’s ratio technique is said to deliver an accuracy of 97.5%, which is not affected by the presence of blood, electrolytes, saline, or hydrogen peroxide. The ZX II automatically calibrates to ensure accuracy and help eliminate the effects of changes in temperature and moisture during treatment. This unit features a large color LCD screen that is easy to see. The action of the meter in the display corresponds exactly to the tactile sensation of using the file. It offers an optional upgrade to the OTR Low Speed Handpiece Module, which snaps onto the back of the unit and offers a unique 90° auto torque reverse and file advancement feature.
This device gives users the ability to customize the “zero point” to help eliminate the need to constantly monitor the visual display—its audio signal will sound when users reach their preferred zero point. Apex ID is designed to work in almost any canal condition, including wet or dry, bleeding, saline, and chlorhexidine. It continuously calibrates for accurate readings in real-time.
KaVo Kerr
888-275-5286 | kavo.com
ApexNRG-XFR™
The ApexNRG-XFR features Xtra Fine Resolution, which is said to give clinicians maximum control over the procedure. Its unique automatic adjustment of measuring current can accurately locate the apical constriction in changing conditions, including wet, dry, and bleeding canals. The device’s audible alarm sounds when the file reaches the 0.5 mm mark and changes pitch and frequency as it approaches the apical constriction. The compact device is lightweight and easy to manipulate during procedures. It includes fully autoclavable accessories, such as lip hooks, apron clasps, sensor probes, and mini file holders.
The ProMark features full canal and apical zoom functionality, providing precise length determination. Its full-color touchscreen display is foldable and adjustable, giving clinicians a close-up view. The DR’s CHOICE function allows users to set their preferred indication line or working length anywhere in the apical zoom’s green-to-yellow section that corresponds to the apical constriction area in the canal. Its folding design makes it compact and portable.
This unit uses 2 measuring frequencies that are alternated, not mixed, eliminating noise and the need for signal filtering. Signal intensity is used to calculate the file tip position, making the measurement immune to electromagnetic interference. Its virtual apex function allows clinicians to mark a predetermined distance from the apex prior to measurement. When this feature is enabled, a clear visual and audio notification is received once the file tip has reached the selected mark. The device offers a 3D user interface based on a high-resolution TFT-LCD color graphic display, which shows the movement of the file inside the canal from the beginning of the measurements to the end.
This device uses an extremely low current of 1/500 mA, which is said to reduce patient discomfort. It has the ability to read under electrically conductive canal conditions, including blood, tissues, pulp, sodium hypochlorite, and other fluid. The large colored liquid crystal display is easy to read, and the device conditions can be confirmed on the display icons. The digital display shows you what you are sensing at the critical apical region (about 3 mm from the anatomic apex) of the canal with an adjustable audio alarm.
Its ergonomically designed display features LED illumination and allows for angled chairside viewing. The molded case can be easily wiped down with most antibacterial wipes for keeping asepsis. It features visual and audible file position indicators.
Its 4½-inch color LCD display make it easy to read, and its adjustable audio feedback provides accurate file location information. The Maxima features automatic calibration and multifrequency impedance-measurement technology to ensure precise measurements. Its automatic sleep mode is designed to maximize battery longevity, and it features built-in testing and demonstration functions.
Incorporating wireless Bluetooth technology, this device is said to eliminate the need for long cables. It features a wireless, 7-in, high-resolution touch screen that links to the mini measuring unit using Bluetooth. The Wirele-X offers a clear and simple results presentation with its informative user interface for easy, convenient operation. It also features a simplified measurements procedure with scale and numerical values along the root canal and beyond the apical foramen. The device is powered by a rechargeable Lithium-Ion battery.
Its multifrequency apical position technology guarantees accurate measuring even in the presence of blood or residual pulp in the canal. Its newly upgraded algorithm makes it more stable and enables stronger anti-interference ability. Results are not affected by the tooth type.
The device features 4-frequencies technology that allows it to estimate working length when used in stand-alone mode. The progress and positioning of an endodontic file can be monitored in the canal in combination with Dual Move mode. It features 7 visual steps between the apical constriction and the apical foramen and an adjustable reference point between these 2 anatomical points.