Page 231 - My FlipBook

with living pulps or upon the natural teeth. A bridge, at best,
will give much less power than the natural teeth, but es-
pecially is the power very much reduced if the pulps have
been removed from the a'butments. I would like for you to
study this carefully with the instrument, and yet be careful
always not to bite too hard upon a tooth that has a large fill-
ing where you are liaible to break ofif a weak cusp. I do not
want any of you to injure your teeth in that way, but I would
like for you to get a good view of these differences in power
that come from the removal of pulps. The fact seems to be
that in the very best of cases the power of the peridental
membrane is very much reduced when the pulp of the tooth
has been removed. On artificial teeth usually about 40
pounds is as high a pressure as I have seen sometimes a little
;
more. In one case I found a pressure of 80 pounds given by
artificial teeth in the upper jaw and natural teeth in the lower
jaw. Crowns ougnt to give a higher pressure than that, but
they rarely do. There is an injury to the peridental mem-
brane in the removal of the pulp, and often in setting the
crown also, that prevents persons fi;om using the teeth with
very great vigor. This should be remembered where it be-
comes a question as to whether or not we should remove the
pulp from this or that tooth.
(Just as this lecture was going to press the gnathodyna-
mometer was returned with a record of trials made by sixty-
seven members of the senior class. This seems to have been
done without any effort at selection. These records show
pressures with the molar teeth all the way from forty to
two hundred and seventy-five pounds, or the total number of
pounds the instrument will register. The average these trials
give is one hundred and seventy-one and six-tenths pounds.)

Management of Children's Teeth.

This morning I will take up the subject of the manage-
ment of children's teeth. In looking over the literature on
this subject I must say that I am greatly dissatisfied with it,
and I suppose I shall be dissatisfied with anything I can do.
It is a very unsatisfactory subject. In general terms I may
say, as I have said in the years before, that the differences are
due to childhood, purely. So far as the tissues of the teeth
are concerned, we may make fillings in children's teeth just

21Q