Allan Deutsch
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 HE
ENTIRE endodontic procedure, from diagnosis through instrumentation,
can be said to be just a prelude to the “fill.” The filling of the
canal with gutta-percha visually displays to everyone all your preceding
efforts and work that have led to this last step in completion of the root
canal therapy. The most important part of this last step is the fitting
of the gutta-percha point. The point must fit well enough so that
you know with the utmost predictability what the final result will look
like, even before you complete the procedure. If the preceding instrumentation
has been done well the point will be very easy to fit and the result will
be predictably excellent. So, exactly what do we do in fitting the point?
Constant modification of our instrumentation over
the years has led us to the EZ-Fill® SafeSider™ technique.
This sequence of instrumentation allows us to fill the canal with gutta-percha
easily, effectively, and quickly. The key to the fill is to
make sure that the last two nickel-titanium instruments, the orange 30/.04
and the brown 25/.08, go to the apex easily with no binding. Once
this is accomplished, we can fit the gutta-percha point and fill the canal.
I use the tapered gutta-percha points (Figure 1).
The 25/.08 prepares the canal to a .08 taper. Therefore, I use a
.06 tapered gutta-percha point. Each manufacturer’s point varies
slightly from the others, but most of the .06 tapered points are very close
to specifications. I use either a 25/.06 or a 30/.06 gutta-percha
point. I select the point depending on how easy it was to instrument
to the apex with the 30/.04. This instrument opens the apex to a
#30.
I now take a gutta-percha point out of the box and
place it in the canal. I use a locking forceps and grasp and lock
the point at my reference mark. I remove the point and measure it
on a finger ruler. Let’s assume for demonstration purposes
that the working length of the canal is 20 mm. When I measure the
point, it will either be right on the mark, long, or short of the measurement.
If it measures 20 mm (about 80 percent of the time) you are now ready to
fill (Figure 2). If it is long (usually by about 1 mm), just take
a pair of scissors and cut off the extra mm. Replace the point in
the canal, lock it at the reference point, and measure it again.
Usually it will now fit. If it does not, just repeat the cut step.
If it is short by 1 to 2 mm, you have a little work
to do. There is an area in the canal that is a little difficult to
clean. It is located about 5 to 8 mm from the apex. With our
technique, you have instrumented 4 mm short of the apex to a 40 and you
have gone down as far as you can go with the #2 Peeso. This sometimes leaves
a “no man’s land” in that 5 to 8 mm zone from the apex. This is usually
where the gutta-percha point is binding. There are two ways to handle this
:
-
Select a different gutta-percha point. They are not all exactly alike and
one point may be more or less tapered than another.
-
Reinstrument this 5 to 8 mm area.
You can reinstrument by :
-
going deeper with the #2 Peeso if possible
-
going 5 mm short of the apex with a #45 stainless instrument then
-
going 6 mm short of the apex with a #50 stainless instrument then
-
going 7 mm short of the apex with a #55 stainless instrument then
-
going back to the apex with the 25/.08.
Once the “no man’s land” is reinstrumented, a new gutta-percha point should
fit to the measurement.
Now that you have fitted the gutta-percha point
to the canal, you are ready to place cement into the canal and permanently
seal the root-canal system.
September-October 2001
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FIGURE 1: Tapered gutta-percha
points.
FIGURE 2: Gutta-percha point
fitted in the canal.
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