Page 94 - My FlipBook

8o METHODS OF FILLING TEETH.
making the following dogmatic statement : The more gradual the
pressure exerted upon gold foil in condensing it, the less it loses its
quality of cohesiveness ; and vice versa, the more sudden, sharp, or
rapid the blow of the hammer, the less cohesiveness will be exhibited.
This is a very important statement, and being true, once recognized
should prove invaluable to the operator. For example, suppose the
Bonwill mechanical mallet, with a very rapid stroke, is being used in
a ; suppose that suddenly, seemingly without reason, the
filling cavity
gold, piece after piece, refuses to cohere with that already packed.
We stop and examine for moisture, but find none. Then we try an-
other and another piece ; perhaps they fail, or they may cohere only
after a few have been added.
to come away again pieces What is to
be done? Is it an uncommon experience ? I think it will be recog-
nized by many. If the reader, the next time he is in that predica-
two or three he will
ment, v;\\\pack pellets carefully by hand-pressiire,
possibly be astonished at the fact that they cohere perfectly, and that
as soon as the whole surface has been covered with the new gold the
mallet may be resumed satisfactorily. This is intelligent alternation
of forces. Again, suppose a large cavity, with a comparatively small
opening. It is found that before the floor is covered, the mallet seems
to have a tendency to induce the filling to leave its retaining-points or
The becomes loosened. and this loose
grooves. filling Again again
piece is removed and the work restarted, but always with the same
result. Begin once more, and fill a good portion of the cavity by
After that, continue with the mallet, and all will be
hand-pressure.
well* Suppose that we wish to use large pellets in a large cavity.
Every now and again the pellet balls up under the mallet, or only one
end of it coheres, so that we tear off and discard the other half. Here
is a time when each large pellet should be partly condensed by hand be-
fore the mallet is brought into use.
The disadvantages of hand-pressure are obvious. It is slow, it is
tedious to both patient and operator, and it does not produce as dense
a More it is a fact that more teeth have been
filling. important still,
broken than where use of a mallet
actually by hand-pressure judicious
has been depended upon. To use a corkscrew plugger by hand in a
deep undercut of an incisor, is to invite the fracture of the corner.
The slightest twist of the instrument brings so mighty a force against
frail structure that the disaster is inevitable. This is a lesson that
students should learn theoretically, rather than practically, as I did.
It is very unpleasant to try to palliate the offense to the patient.
Again, a plugger is more likely to slip by this method than where the
mallet is in use. The force exerted is a continuous one, and practically
limited only by the resistance. Thus, if the resistance gives way, as
when the instrument rests at an improper angle so that it may slide