Dr Yoshi Terauchi's The Art of Safety Canal Instrument Removal workshop @ 11th MES-SES Biennial Joint Scientific Conference 2018

Back in November, I had the opportunity to attend a full day workshop entitled ‘The Art of Safety Canal Instrument Removal’ by the world-renowned endodontist in instrument retrieval, Dr Yoshi Terauchi. I first came to know about him during one of my discussion of managing separated instrument with Dr Alok when I still in undergrad. I am aware that Dr Yoshi do host workshops in Japan but they are way too expensive. It was a dream came true when MES announced that he will be coming to town and I quickly sign up for the course minutes after registrations were opened. Sadly, of all days, my GPS went haywire that morning and I was about an hour late! I was frustrated that I missed out the initial part of the lectures but thankfully he was still warming up in his presentation. I thoroughly enjoyed the lecture he gave as it was generous with visual diagrams and video demonstration to help us understand and convince us of the points he made. We first learn in depth how unwanted mishap in endodontics happen in the morning and then the art of retrieving separated instruments in the afternoon.

My learning station

We were asked to willfully create a ledge in an acrylic block and learn how to bypass it. The importance of prebending the # 10 K File was stressed over and over again. I must say the SybronEndo Endo-Bender is one neat instrument for that but it comes with a heavy price tag. After that exercise, we were required to separate (break) the NiTi file in the block! (We were provided with the TF Adaptive Motor and Files to practice and it sure feels like driving a BMW- Endo style) Learning to break the instrument intentionally really help me understand how such mishap happened clinically and how to move on from there. Sometime our emotions can get the worse of us and we have a mental block to handle the situation.

Recipe to break the file

Successfully separated the new file

Keep Calm and retrieve the instrument with – TFRK technique!

The Terauchi File Retrieval Kit 

Each participant was then given a TFR kit (that we can bring home!).  Dr Yoshi 99.7% success rate in retrieval made me ponder on one thing which I never gave much thought about in Endodontics: ‘PREDICTABILITY’. I continue to see this theme running through the MES conference ‘How to make your work predictable?’ – through an established protocol with evidence. Dr Yoshi continue the afternoon by introducing the TFR kit and the 3 main factors in instrument retrieval: Motivation, Profit, Predictability. He presented to us his usual recipe and systematic approach to handle separate instruments. I’m not sure if I can share the photos of his slides here without his permission but here is a youtube video link if you want to learn more: https://www.youtube.com/watch?v=o6Ah2kaOeMI

We then practice his technique under magnification on Tru Tooth models which have a broken instrument is already present in them.

I was lucky to get to practice on this Zeiss OMI PROergo model!

Struggled with this tooth

Out in 10 sec

The following is just a brief summary of some take away points from this workshop and the MES conference lecture:

On Ledges

-          Don’t try to run when you haven crawl. Ledges can easily be created with large stiffer files like #20. To bypass irregularities and create a glide path for your rotary files, use a #10 K file with 30 degrees bend on the apical 1-2mm, push and pull in an up down motion about 50 times till the files is super loose. Note if you precurve the file too much (5mm from apical end), file become straighten when inserted into the canal.

-          If a ledge is formed while negotiating the canal, locate the ledge under magnification, enlarge the canal to the ledge, pre-curve the negotiation file, and use it with push-pull motions. the key to success in bypassing the ledge is to push a file in an inner direction rather than straightforward. Do no rotate the file, just try to hug the inner wall and maintain the precurvature of the tip.

-          If the ledge is not visible, first enlarge the canal with #3 GG bur till level of the ledge. Locate ledge on the outer wall. The opening to the canal is always on the inner wall, opposite to the ledge. Place a precurve # 10 file to get into the original canal. Then you can use SM1/path files in pecking motion at 100 rpm (slower rpm easier to get into the ledge) to bypass the ledge

SM1 file with 100 rpm 

Successful bypass the ledge

       On instrument retrieval

-          Try to think positively when you break the instrument. ‘Its ok, now I can practice instrument retrieval and it is a predictable procedure’ Psychological factors will affect your ability.

-          We need the motivation to carry on our work so never short change yourself. You are providing dental treatment for your patient health not at the expense of your own pocket. Charge you patient enough to make yourself happy and feel it’s worthwhile. No free lunch in the world

-          Location of the coronal end of the fragment is important to assess the difficulties of instrument removal. Before curvature & visible file: easy. Beyond curvature & not visible: difficult

-          The method of retrieval depends on degree of canal curvature and length of the broken instrument. More than 30 degree curvature or > 4.5mm length of broken instrument might need the use of the Yoshi Loop. Always start to use the ultrasonic first, make sure the instrument is dancing before proceeding with the loop. (The mean length of # instrument is 2.5-3.5mm, more commonly with large files)

-          Separated instruments are usually lock in at the its coronal 3^rd. No dentin will be surrounding the middle and apical 3^rd. The concept essentially is to create space in the coronal 3^rd on the inner wall (careful not to touch the instrument) with ultrasonic till you see the instrument is dancing before move on to retrieval. Never touch the tip of the ultrasonic on the instrument as there is a risk of file extrusion or secondary # of the broken instrument.

-          Always refer to axial view as axial view of CBCT is similar to what you see under DOM.

-          To assess/diagnose look only at the coronal portion of the # instrument, measure the length need to remove dentin. The longer the instrument, the longer it will take as more coronal 3^rd length to remove

As a whole, I was really inspired by Dr Yoshi who dedicated his career in providing a solution with simplicity and predictability when facing with such stressful mishap. I do feel that the time for the workshop was a little short and I would love to have more time to work on the extract tooth that I brought along for the course. It was really sweet of him to agree to drop by Malaysia on his birthday to teach and share his experience and technique with us.

Please continue to stay tune as I have a couple of things I have stored up in my drafts that I plan to share. I will try to be more discipline and get them finished. Till next time, take care!