An Ode to the apex locator

Being quite a sad individual I often find myself discussing endodontics. I am frequently asked by colleagues for my opinion on the latest tech or gadget of which there are an overabundance. I am a sucker for a shiny new toy which I suppose why in part I was drawn to the practice of endodontics which has lots of them.

Over the years innovators have brought to market a multitude of devices and gizmos that for the most part improve our delivery of endodontic treatment, if not our treatment outcomes. Of these very few fall into the essential must have or I’m going home category. So what might you ask is essential kit for endo? What could you not work without? My list would be: 1. Rubber Dam; 2. Apex locator; 3.Microscope with CBCT ever increasingly sneaking onto the list. Everything else is a luxury.

I would like to spend some time discussing the merits of number two, the oh so underrated apex locator. Despite the fact that next year will mark the centenary of Custer’s novel invention many practitioners still carry out root canal treatment without the aid of an apex locator which I find somewhat baffling. So what’s so great about it and why should you use it anyway?

The aim of root canal treatment is to locate, clean and fill as much of the root canal system as possible. This begs the question as how do we know we have cleared as much of the canal as possible and how do we know that we have got to the end of the canal? Historically this was done using radiographs. The major pitfall of such an approach as the pictures below are intended to illustrate is that the apical foramen seldom coincides with the radiographic apex and in some teeth there can be as much as a 2-3 mm discrepancy in their relative positions.  Although radiographically we may think that we are spot on, the reality is astonishing different! 
In a procedure where each and every millimetre makes a difference practitioners need a tool that has the ability to reliably and accurately determine the length of a canal. This can be achieved with the trusty apex locator. I will spare you the formulae but the latest generation of apex locators work on a function of resistance and capacitance known as impedance and unlike Custer’s original model that worked on direct current, are painless for the patient.  Using multiple frequencies to allow working in dry or wet canal conditions modern apex locator are around 95% accurate at locating the apical foramen (CDJ) and therefore, are far superior to radiographs. 
I certainly could not work without mine, which I have in constant use throughout the procedure. Of all the gadgets the apex locator is most likely to spark the patient’s interest as they are keen to find out what all the beeping was about. In addition to working length determination the apex locator can be used to identify perorations or canal blockages. As with any new equipment there is a learning curve but once you get to understand it beeps and tones you will quickly learn to love it and your treatments will greatly benefit. 

For those of you who have yet to join the revolution, try it out. I can assure you that you won’t look back and be delighted with your brand new 100 year old apex finder!

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About Us

The Academy of Advanced Endodontics is a specialist endodontic practice delivering high quality patient diagnosis and treatment together with endodontic training for all levels of practitioners.

A team of training specialist endodontists is lead by Richard Kahan and all treatment is supervised by Richard.