Allan Deutsch
 
 

Figure 1

    In a single-point technique such as the EZ-Fill® obturation technique, we aim for filling 95 percent of the canal with gutta percha and the remaining 5 percent with the sealer (EZ-Fill epoxy cement).  The sealer in essence is what seals the canal, not the gutta percha!
    The first thing we do is remove a medium GP point from the box with locking college pliers (Figure 2).
 

Figure 2

    Next we place it into the canal until it stops. We then begin to pull it out of the canal to see if there is “tug back.”  Tug back is that feeling of the GP point sticking in the canal as you try to remove it, causing you to apply a little extra force to remove the point from the canal.  When you do achieve tug back, it means that the GP point is binding somewhere in the canal.   Figure 3  demonstrates the medium GP being placed into the canal.
 

Figure 3

    Once we establish that there is tug back, the GP point is locked in place at the measurement with the locking pliers  as shown in Figure 4.
 

Figure 4

    The GP is now measured and compared against the working length measurement obtained with the apex locator, as in Figure 5.
 

Figure 5

    We have found that approximately 85 percent of the time the medium GP point fits the canal to our working length measurement, as in Figure 6.
 

Figure 6

    We can now remove the locked GP point and place it to the side while we then place EZ-Fill sealer in the canal with the bi-directional spiral.
    I have found that about 5 percent of the time when I fit the GP point in the canal it is too long. That is, when I remove the GP point from the root and measure it , it measures longer than my working length measurement. (See Figure 7.)
 

Figure 7

    When this happens, it means that the tip of the gutta percha point is sticking out the apex into the ligament and  bony tissue, as shown in Figure 8.
 

Figure 8

    Clinical research is showing that long fills are less successful than obturation to the apex or 2mm short of the radiographic apex.  I then remove the GP point and cut the apex until my working length. measurement is achieved (Figure 9).
 

Figure 9

    This is repeated if necessary until the tug back at the correct working length is achieved.
    Lastly, about 10 percent  of the time when I fit the gutta percha point it is short of the working length, as in Figure 10.
 

Figure 10

    This means that the canal is under-prepared and not tapered enough (Figure 11.)
 

Figure 11

    The area where the GP point usually binds can be found approximately 2?5 mm from the apex.  Therefore we must remove the GP point and reinstrument the canal, paying close attention to this 2?5 mm area.  I generally will go back into the canal with my number 2 Gates Glidden first and try to get it within 3 mm of the apex or as close as it will go.
    Next I will place my NiTi 25/08 in the Endo-Express and instrument to the apex until it is very loose (Figure 12)
 

Figure 12

    I next try the GP point back in the canal and generally it goes right to the working length measurement, as in Figure 13.
 

Figure 13

    Once you the fit the medium gutta percha point to its correct measurement you are guaranteed that when you take your final x-ray it will be exactly where you fitted it to in the canal.  When it comes to endodontics, I do not like surprises.