Page 235 - My FlipBook

SYSTEMIC CONDITIONS. 119
These differences were supposed to be considerable, and caries
was supposed to be severe in teeth that were very soft.
The fact is, that heretofore, when it was discovered that
the teeth of an individual were decaying very rapidly, the inter-
pretation was that the teeth were poorly calcified and were soft.
If, after careful treatment, little or no decay occurred, it was
supposed that the teeth had become hard and firm. Again, if
a person had arrived at maturity with little or no decay of the
teeth and later it was discovered that the teeth were decaying
very badly, the interpretation was that, while the teeth had been
very good in their structure, sometbing had happened to cause
them to become soft, and therefore they decayed badly. In this,
the observation of clinical facts has been correctly reported.
Many persons have grown to maturity without decay of the teeth
and afterward their teeth have decayed very badly. It was quite
generally held that, during pregnancy and lactation, tbe teeth
of the mother were robbed of calcium salts to build up the bones
of the fetus. This was because of the general observation that
during such periods the teeth of women suffer more from caries
than during other periods. These observations were shown to
be correct by the testimony of many observers, and lines of
treatment were undertaken for tbe correction of the supposed
loss of calcium salts in tbe teeth. A large proportion of people
who have decay in their youth, will, if that decay is well cared
for, cease to have much decay later in life. This gave rise to
the general opinion that the teeth were inclined to become hard
with advancing age. These observations were carried on and
discussed more or less for years, serving to fix the interpretation
mentioned in the minds of both the dentists and the people. In
fact, there seems to have been no question as to the correctness
of the interpretation.
In 1895 I published a series of studies (Dental Cosmos, Vol-
ume 37, page 353) which were undertaken to determine the facts
as to the differences in the physical properties of the teeth with
reference to hardness and softness, as represented by the per-
centage of calcium salts in tbe dentin, and the relation this held
to caries. The results of this investigation are given in great
detail, but for our purpose very little of it need be repeated.
The results surprised myself as much as they surprised others,
for it was found that there were no differences of consequence.
I give here a summary of that investigation, which will show
the actual facts and also tbat the interpretation of soft teeth
and hard teeth, as that interpretation then stood in the minds