Removal of Separated Instruments from the Root Canal System




One of the most difficult tasks to accomplish when performing Root Canal Treatment is the removal of a separated instrument from within the root canal space (see Figure 1 below). Traditionally, these cases are handled by trying to bypass the broken instrument. Extractors utilizing cyanoacrylic cements have been tried too. Unfortunately, these techniques are time consuming and usually not successful.
With the use of the microscope we have implemented a technique described by Gary Carr. The technique requires modifying a Gates Glidden bur (usually a Number. 4 or a Number. 5) by removing the bottom half and thus creating a flat cutting surface (see Figure 2 below).






Figure 1

Figure 1:
An illustration shows a separated instrument in the apical 3rd.



Figure 2

Figure 2:
Modified Gates Glidden bur, with the bottom half removed.

Ultrasonic Tips:

In addition, it is necessary to use very fine and sharp ultrasonic tips, like the ones designed by Cliff Ruddle (refer to Figures 3a and 3b in Ultrasonic Tips below), with an ultrasonic unit (refer to Figures 4 and 5 in Ultrasonic Units below).






Figure 3a
Ultrasonic tips with a Zirconium Nitride coating


Figure 3a






Figure 3b
New Titanium CPR ultrasonic tips.


Figure 3b






Figure 4:
New ultrasonic unit by Amadent.


Figure 4






Figure 5:
EIE ultrasonic unit can now be used with universal tips


Figure 5
Modified Gates Glidden:

Step Number 1 involves the exposure of the broken instrument so it can be visualized by using the microscope. The crown down technique utilizing Gates Glidden burs is preferred. Once this is accomplished, we use the modified Gates to enlarge the canal to the point where the instrument is located (refer to Figure 6 below), this way we will create a platform that will enable us to properly visualize the broken instruments (refer to Figure 7 below).



Figure 6

Figure 6:
An illustration shows the modified Gates Glidden enlarging the canal.






Figure 7:
An image taken with the Surgical Microscope shows the platform created by the modified Gates Glidden bur.


Figure 7


Enlarging the Canal:

Step Number 2, with the ultrasonic tip we create a trough around the coronal 2 mm of the separated instrument, at this point, the instrument can be vibrated with the side of the tip (refer to Figure 8). It is now that the separated instrument will magically start to spin and move coronally so it can be easily removed. Persistence is the name of the game. I have found that most broken instruments can be safely and quickly removed by following this simple technique (refer to Figures 9a and 9b). It is important to mention that Ni Ti files will usually vaporize when using ultrasound thus making their removal an almost impossible task.







Figure 8

Figure 8
Placement of ultrasonic tip around the coronal 2 mm of separated instrument






Pre/Post Radiographs:





Figure 9a
Radiograph shows a Sectional Silver Point prior to retreatment.


Figure 9a






Figure 9b
Post-op radiograph shows a completed root canal with the Sectional Silver Point successfully removed.


Figure 9b

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another simple technique for removal of broken instrument from root canal is bypassing technique,widen the root canal with larger instrument eg. if last number used were 30, now further enlarge the canal upto 50 access the broken piece of instrument go parallel to it,take a H file and pull it out.