Allan Deutsch
FIGURE 6: Cutaway view.
FIGURE 7: The PulpOut bur
in a calcified pulp chamber.
FIGURE 8: Preparing the axial
walls of the chamber.
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THE SUMMER 2004 issue of Endo-Mail, I talked about the
research we presented at the IADR meeting in Honolulu. The morphological
research on molars was just published in the June issue of The Journal
of Endodontics (2004;30(6):388-390). This research showed that
there are some very consistent measurements when it comes to molar pulp
chambers. These measurements in conjunction with the use of the PulpOut
bur will allow you to gain access to the chamber (even in calcified chambers),
easily, quickly, and without perforating into the furcation.
Some measurements to remember are:
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The pulp Chamber Ceiling is just about always at the level of the CEJ!
See Figure 1.
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The height of the pulp chamber is between 1.5 mm and 2.0 mm for the average
non-calcified tooth. See Figure 2.
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The average distance from the floor of the pulp chamber to the furcation
is about 3.0 mm. See Figure 3.
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Last but not least—the distance from the cusp tips to the ceiling of the
pulp chamber in molars is approximately 6.30 mm. See Figure 4.
This is the most critical distance of all. Using this measurement, we have
developed an instrument that will allow you to find the pulp chamber in
all teeth, (normal or calcified)!
That instrument is the PulpOut bur. It is a number
four round bur with a hard plastic non-movable stop fixed at 7.0 mm from
its tip. See Figure 5. The 7 mm distance enables you to gain access
to the pulp chamber without risk of going through the pulpal floor and
into the furcation. For teeth with average-size pulp chambers, the PulpOut
bur will place you somewhere in the middle of the pulp chamber. See Figure
6.
For teeth with calcified chambers, it will place
you on the floor of the chamber. See Figure 7.
As we age, the pulp chamber normally calcifies from
the floor up. Therefore, the 7 mm distance will place the bur in
what used to be the middle of the chamber but now is the floor. This
will then enable you to find the canals much more easily. Once the
general outline of the access is made with the PulpOut bur, the diamond
shaper is now used. The diamond shaper is a non-end-cutting coarse
barrel diamond. It is placed against the axial walls and moved around the
entire access opening. This will smooth the axial walls and let more light
in to the floor. See Figure 8.
The diamond is extra long so that the entire axial
wall from floor to occlusal surface can be cut in one operation. The non-end-cutting
tip of the shaper will not cut or gouge the floor of the chamber.
Once these burs are used, finding canals without perforating
the furcation becomes very predictable and easy.
Fall 2004
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FIGURE 1: The pulp chamber
ceiling is found at the level of the C. E. J. 98 percent of the time.
FIGURE 2: The average height
of a pulp chamber (F) is 1.5 to 2.0 mm.
FIGURE 3: The distance between
the pulpal floor and the furcation (measurement A) equals 3.0 mm on average
for both mandibular and maxillary molars.
FIGURE 4: The mean distance
(E) from the cusp tip to the pulp chamber ceiling is 6.36 mm in mandibular
molars and 6.24 mm in maxillary molars.
FIGURE 5: The PulpOut bur’s
non-movable stop is fixed at the critical 7.0 mm pulp chamber depth.
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