1) Why would my instrument show red light when it has only entered the canal?

It can be either due to a wet pulp chamber or the file has encountered a metallic restoration. In both cases, short circuit is responsible for inaccurate readings.

2) Why reading on the unit is not steady?

It means that file is not in continuous contact with the canal wall. Try to use bigger size file so that the tip touches the wall near the apex.

3) How an apex locator improves my practice?

Every root canal that you enter vary in their length. Therefore, it is important to use an apex locator which will help you determine the proper working length easily and accurately. It reduces the complication like apical perforations. Without the Apex locator you will never know where the file is in the canal. It also minimises the number of x-rays needed for the completion of the procedure.

4) What are the classification of Apex Locator based on its generation?

  • First generation Resistance Apex Locator: This gives false reading on the presence of blood, pus, chelating agents and irrigants in the root canal
  • Second generation Impedance Apex Locator
  • Third generation Frequency dependent Apex Locator
  • Fourth generation

5) What is Apical Constriction?

Apical Constriction (AC) is the narrowest part of the root canal and is considered as the apical limit of canal instrumentation and obturation. It is also a morphologic landmark that helps to improve the apical seal when the canal is obturated. For the success of endodontics treatment, accuracy while determining the working length is paramount. The distance between the coronal reference point to the point at which obturation and canal preparation terminate is defined as the working length.

6) What is multiple frequency technology and the frequency ratio?

Third generation Apex Locators use multiple frequency to determine the distance from the end of the canal. With powerful microprocessors, they can process algorithm required to give accurate readings. The Apical constriction can be located by the relative values of frequency response method by calculating the difference between two direct potentials picked up by filters when a 1kHz rectilinear wave is applied to the canal.

7) Advantages of Multiple Frequency Technology

  • Achieve fast response
  • Can control electrical devices wirelessly
  • Less power consumption