Page 728 - My FlipBook

738 DENTAL CARIES.
best of liuman thought and intelligence, and the deductions from all
observations except their own, were diametrically opposed to their the-
ory (a theory which all of the labor of the years intervening up to
the present time has hardly been sufficient to demonstrate), that the laws
of fermentation were very little understood, and that they had not the
means of confirming their suppositions by direct experiments made
either by themselves or by others, their writings seem very remark-
able.
AVhile their knowledge w^as limited within a comparatively narrow
range, and their work as a whole exhibits less of learning than that of
many of their contemporaries, yet they perfectly agree on this point,
and evidently arrived at the true conclusions regarding it from a close
analytical study of the phenomena of decay as they observed them.
The generally erroneous nature of the thought and observation of
that period is well expressed in the arguments against these views by
Desirabode.
The bold denial by these men that caries ever had its beginning
within the dentine, as its truth was gradually established, had, however,
great weight in confirming the chemical hypothesis.
It is exceedingly curious to note that in accepting the chemical
theory a large part of the profession either misunderstood or lost
sight of its main facts as related by the authors I have mentioned.
Perhaps the most prevalent error, and one that has been most persist-
ently prominent, is that contained in the objection that was imme-
diately expressed by INI. Desirabode—namely, that if acids caused
decay, they would, from their necessary general distribution in the
mouth, act upon all parts of the teeth, instead of spending their force
on particular points. It will be seen at once that the idea of the local-
ized development of an acid by fermentation is lost sight of in the
expression of this objection. If the acid enters the mouth with the
fluids as they are secreted by the glands, or with the food, or in any
manner by which they would be generally distributed, there is no reason
why they should act at particular points only.
On the other hand, much confusion has arisen through the supposi-
tion that caries might be caused by acids commingled with the fluids
of the mouth or introduced from without. This is the form of error
that has been most persistently present in the writings on this subject
up to the present time. I may say that the acidity or alkalinity of the
general fluids of the mouth or of the food plays but a small part in the
case, ])rovided these reactions be not in such degree as materially to
modify the act of fermentation taking place in the out-of-the-way points
about the teetli. The teeth may decay when the fluids of the mouth
are habitually acid or when they are habitually alkaline. The condition
governing the beginning and progress of caries is neither of these, but is
dependent directly on the lodgment of substances at particular points
and their fermentation with the production of an acid. It is in this
manner that caries has its beginnings, and its progress is maintained by
the continuance of this act of fermentation.
The faijure to grasp this thought in its full meaning was perhaps
quite natural. This subject of fermentation has been one of the most