Allan Deutsch
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THE JANUARY-MARCH 2006 ISSUE of the Endo-Mail newsletter, I discussed how
to fit a gutta percha point. I just returned from the Thomas P. Hinman
Dental Meeting in Atlanta, where several dentists asked me which GP point
to buy and use now that they knew how to fit it. My first reaction
was, “That is pretty easy.” Then I took a look at my bracket table
and saw that my assistant Nichelle keeps about five sets of different brands
of GP on the table. Not so easy after all. So let’s go through
the criteria that I use to decide where I use what.
First, let’s talk about gutta percha shape and size.
Once we have completed instrumentation with the SafeSiders® sequence,
we have prepared the canal to a .08 taper and either a #30 or #35 at the
apex. This preparation happens to fit a medium gutta percha point
very closely. However a medium GP point is not standardized among
the manufacturers. Consequently, a medium point from one manufacturer
is just slightly different from a medium point from another. Usually,
the difference can be seen as a difference in the size of the taper, the
size at the apical end of the GP point, or both. The figures accompanying
this article illustrate medium points from several manufacturers.
The Schein medium point seems to be slightly thinner
in diameter than the Dentsply medium point at all levels (Figure 1). Therefore,
in a case where the canal is very tight and I have not worked my brown
NiTi 25/.08 taper all the way to the apex, I try the Schein point first.
In addition, for those very curved or tight canals where instrumentation
with the 25/.08 is difficult, we have now introduced a pink NiTi 25/.06
SafeSiders instrument. This instrument is easier to get to the apex
and once used will allow the 25/.08 to get to the apex much more easily
in those difficult cases.
Knowing which points are thinner at the apical end
and have a narrower or wider taper will make fitting a GP point that much
easier in a difficult curved canal. Unfortunately, because of the
curved nature of most canals, our preparations (even though we follow the
same sequence) do not produce exactly the same shape on every root. Consequently,
there can never be just one gutta percha point that will fit every canal.
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| FIGURE
2: Dentsply Maillefer medium gutta percha points. |
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“Standardized” .06 taper GP points also work very
well with the SafeSiders preparation sequence. However, even though
these are supposed to be standardized, points from different manufacturers
are once again slightly different in shape and size. Ideally a white
#15/06 taper GP point will start off at 0.15 mm at the apex and get larger
by .06 mm for every mm of length. The yellow is a #20/06 and starts
off at the apical end at 0.20 mm and increases by .06 mm for every mm of
length. This is how a .06 taper works. Figures 3 through 7
show various .06 taper GP points from different manufactures. In
very curved canals, if I only go to the apex with a #20 or #25 SafeSiders
instrument, I will try a yellow 20/.06 or red 25/.06 and use the one that
fits better.
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| FIGURE
3: Assorted sizes of Lexicon .06 taper gutta percha points. |
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| FIGURE
4: Gutta percha points from Meta, followed by closeups of 20/.04, 25/.04,
30/.04, 20/.06, 25/.06, and 30/.06 points. |
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| FIGURE
5: Diadent .06 taper gutta percha points, with closeups of the 25/.06 and
30/.06 points. |
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| FIGURE
6: ProTaper .06 taper points. |
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| FIGURE
7: Endomagic 25/.06 point. |
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Figure 8 is a side-by-side comparison of 30/.06 taper
GP points from five manufacturers.
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| FIGURE
8: 30/.06 gutta percha points from A: EndoMagic, B: Meta, C: Diadent, D:
Lexicon, E: ProTaper. |
First, notice that the length of each point differs
slightly from the others.
Next, apically they are all supposed to be a 30.
However, A looks to be the thinnest, then C, B, D, and E, in order of increasing
thickness. In a case that is tight with a #30 SafeSiders instrument
at the apex, I will try the A point first.
The tapers also look different. They do not all
seem to be the same .06 taper. A seems the biggest, then C, then
B, then D and E. If the fitted GP point does not go to the apex,
it is usually because the point is binding approximately 3?5 mm from the
apex. The first thing to do in that case is try a thinner point.
These are D and E. If they fit, great; if not, try to open the canal more
with the #2 Gates or the 25/.08 or both.
Personally, I have found the Lexicon (D) to have
the best fit most often. With its slightly thinner taper and thicker
tip, I believe it is binding at the apex more often. I find that
crimping or buckling at the apical end of the point are rare with the Lexicon.
Buckling in the apical 1?3 mm is caused by the point’s being much smaller
in diameter than the apical preparation of the canal. When the point
is placed and a small amount of pressure is applied to seat it, the point
then buckles.
It is rare to find any technique or instruments
in dentistry that work in 100 percent of the cases. Unfortunately,
gutta percha fit is no exception to that statement. My suggestion
is to have several manufacturers’ GP points on hand to make your GP fit
step a lot easier!
April-June 2006
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| FIGURE
1: Comparison of Dentsply and Schein medium gutta percha points. |
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