The terms "apexlocation" and "apexlocator" include various methods for determining the true root canal length.
If in the recent past it was necessary to focus exclusively on the "red dot method"( the presence of a blood stain on the top of the paper pin), or on the patient's reaction( feeling of an easy prick when reaching the necessary depth of the canal), or on the tactile sensations of the dentistThe method of radiography( alas, two-dimensional) came to the rescue.
And only with the accession of electronics appeared reliable devices, not only guaranteeing the accuracy of measurements, but also providing the translation of the three-dimensional image of the investigated area. After a change of several generations apekslokatory could function not only in a dry and clean dental canal, but also in less comfortable conditions.
Why, for the most accurate estimate of the length( depth) of the channel to be developed, it is necessary to use electronic 
apexlocators? The answer is directly related to the structure of the apex( apex, apex) of the tooth.
For the physiological concept of "apex" includes not only the true apex - the radiographic "peak" of the tooth root with the cone of the large apical opening on it, but also the region of the apical constriction that connects it with the root cavity channel like the hourglass neck.
Here to guarantee the accuracy of determining the level of location of the apical constriction, as the most relevant for the processing and sealing of the zone, and the use of electronic equipment is required.
Because during endodontic intervention, it is not enough to determine its level, either from emerging tactile sensations, or even from using the X-ray method. In turn, the inadequacy of the treatment of the apical constriction zone nullifies the effort to work the entire canal.
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Content of
Content of
Operating principle
Principle of operation
Principlethe action of the device for apex deployment is based on the different resistance of dental tissues to electric current: for solid enamel and dentin this indicator is the highest, and for much friable tissues of periodontal and mucous it is much lower.
The closure of the electrical circuit with the inclusion of 2 electrodes( one of which is located on the lip, the second one descends into the depth of the investigated channel) occurs at the moment of reaching the second periodontal tissues. The point of maximum drop in impedance( resistance), graphically recorded on the display, is the level of apical constriction.
The peculiarity of the 5 and 6 generation devices, which include Raypex 5 and 6( VDW), are the clarity of the image on the color LCD display, which is achieved through a high-precision digital impedance measurement technique.
Technically, the process looks like a gradual immersion of the investigating file into the slightly moistened cavity of the root canal, while the second electrode is immovably fixed to the lip opposite the tooth being examined.
A dentist who monitors the progress of the file on the monitor screen, when the last reaches the apical constriction zone, receives a clear three-dimensional image of the apex with a fixed location of the file relative to the apical opening.
Basics of apex deployment for 5 minutes:
And comparison of popular models:
Consider the TOP-5 of the most popular apexlocators.
NovApex is undoubted leader
The purchase of the apexlocator of Israeli production NovApex( Forum Engineering Technologies Ltd.), guaranteeing the accuracy of the localization of the apex at the root canals, gives other indisputable advantages in the form of: 
- of high accuracy of measurements both in the channel drained and in the filledliquids( including blood, pus, saline solution, potassium hypochlorite and other solutions);
- completely autonomous operation with automatic disconnection of the device, with notification with adjustable mode of sound signal;
- the possibility to fix the device on clothes or in a stand.
The included device charger simplifies maintenance.
The cost of the device is 21 750 rubles.
Root ZX mini from J. Morita
Japanese small-sized( 60x103x57 mm) Morita dental apeklokator with a warranty period of 2 years and the choice of body color( blue, red, white or green) has the following advantages:
- ,conditions( temperature, humidity, etc.) inside the channel;
- the possibility of using the device in the process of treatment;
- no need to set the device to "zero" before each measurement.
Cost of the device with a discount of 46 350 rubles.
German Raipex 5 - quality and reliability
German digital apex locator of the 5th generation Raypex 5( VDW GmbH) is the device that retains the best in its category for 4 years( from 2006 to 2009) according to the evaluation of the European Endodontic Society due to:
- the maximum possible accuracy of measurements made in an environment with the most extreme and unpredictably changing properties, including biologically active liquids and solutions of medications, with the precision of the topography of the file in the channel;
- reality of determining the presence in the channel of both perforations and lateral channels with the possibility of their differential diagnosis;
- to the existence of a demo mode, using which one can explain the operation principle of the device to a patient with the possibility of personally using the
to establish by their own sensations a "virtual apex" - the point at which the frequency of the device's sound signals will increase significantly.
The technical equipment of the model is characterized by the availability of a test electrode and a testing device( for evaluating the operability of the apparatus and cables), as well as the instruction on the CD-ROM.
The cost is considerable - 41,800 rubles, but the device is certainly worth its money.
Raipex 6 is the eldest brother of the best of the best
. All of the above applies to the 6th generation Raypex 6 electron-digital apex locator of the same manufacturer.
The device with unique in its kind HI-TECH design "Touch &Zoom "(with high resolution touch screen and intuitive user menu, designed for accurate and fast navigation).
For the ultra-precise measurement of the channel length, the instrument uses an electronic method for determining its depth, which at times exceeds the X-ray depth. And the clarity and ability to optimally adjust the sound of the acoustic signal allows us to ascertain the length of the channel under study, without looking at the screen of the device.
The price of 53,700 rubles is mitigated by the savings, thanks to the manufacturer's discount, which is 9,800 rubles.
DTE DPEX III - China is not slumbering
Digital high-contrast device of Chinese manufacture DTE DPEX III is a device of increased accuracy, with color display 
produced by Woodpecker and costing 12 400 rubles belongs to the third generation of apexlocators.
Allows you to make measurements with an accuracy of at least 98%, while still being widely available and understandable to users of the device.
The multifrequency program of the apical positioning excludes the influence of extraneous factors on the accuracy of the measurements made, which does not depend on the tooth category, nor on the condition of its channel and the humidity level in it.
A nice technical addition is the availability of a rechargeable lithium battery.
Availability in the consumer market of high-precision apex locators of various price categories allows not only to equip the dentist's office with the latest demand for progress, but also to make endodontic manipulations quickly, accurately and with the required level of quality.