Page 197 - My FlipBook

PREPARING ROOT-CANALS.
183
It is only by an appreciation of the fact that the roots of teeth are of
all manner of shapes, and that the crown is not a sure indication of
what we may meet in exploring the roots, that we can hope to exercise
that precaution and attain that skill which will make it possible for us
to reach that point where we can even fool ourselves into the belief
that we are filling all roots to the apices. Yet it is essential that, how-
ever the obstacles
great may be, we should endeavor to do this ; and I
will now try to explain the best modes of so doing.

METHODS OF GAINING ACCESS TO AND PREPARING ROOT-CANALS.
Before a root-canal can be properly filled, it must be thoroughly
cleansed and made accessible for the material which is to be used.
Admitting that many conditions might occur, as has been indicated
by the foregoing illustrations, where it would be impossible or most
difficult to fill some canals, it yet is true that many of these can be
approximately well cared for where proper methods are employed,
and patience and skill are brought to bear upon the obstacles. Con-
versely, many simple canals are often improperly filled through lack
of skill or from laziness. The first object is to attain free access to
the canal.
Central Incisors. The central incisor having ordinarily a straight
of
canal, usually fairly large size, should offer few obstacles to proper
treatment. The cavity of decay must occur either upon one approxi-
mal side, upon the palatal, or upon the labial surface. Where it is
upon the palatal, the canal is readily entered from that point. When
upon the labial, unless the cavity is well extended toward the incisive
edge, so that it is not difficult to get directly into the canal, I should
make a new opening at the palatal surface. Where the approximal
I should do the same a
cavity is small, ; but where large, simple
extension of the palatal border of the cavity should be made until a
nerve-canal instrument could be made to enter the canal without
bending.
Thus it is seen that I advocate entering the central incisor from the
palatal surface. This would also be the case where a pulp had died
from traumatic disturbance, and, no cavity being present, a drill
should be passed in at the point indicated. The enamel being un-
broken, and therefore resistant to the drill, it is well with a small
corundum point to grind off the polished surface, after which the drill
The drill should be
will cut readily. sharp and small, making a nar-
row opening to the pulp-chamber, which is afterward enlarged with
fissure-burs. A cone bur also does this rapidly. Fig. 231 is dia-
grammatic, and indicates the relation between the usual opening of
this character and the pulp-canal. Through such an opening it