Page 257 - My FlipBook

SYSTEMIC CONDITIONS. 129
It will be found by a review of the dental literature, that
decay of the teeth of man was generally supposed to be because
of imperfection in their structure, and many times it has been
said that the teeth of man were degenerating and were not so
well calcified as the teeth of animals. After a long series of
studies, Dr. Williams' opinion was exactly the reverse; and
further, that the decay of the teeth of man was not to be attrib-
uted to their faulty structure. This opinion seems to have been
well supported by the histological structures developed by his
microscopic work. His work took a wide range among the lower
animals.
As I had been studying gelatinous masses formed on the
teeth by microorganisms and their influence in shielding the
organisms growing in them from washings by the saliva, which
would dissipate the acids formed, I was much interested in this
phase of his work. But later, in the study of his illustrations
and methods, comparing these with my own work along similar
lines, it seemed that he had included all manner of material that
contained microorganisms (practically any material clinging to
the teeth contains them), going wide of the line of those forms
of fungi known to produce caries. He seems also to have included
deposits through which water would run so easily that they
would be no bar to washings by the saliva. Such coatings are
found plentifully over the surfaces of the teeth of immune per-
sons, and also in others where there is no decay of the enamel.
Careful study shows that many kinds of deposits upon the teeth
present similar appearances, when seen in microscopic sections,
to those produced by gelatinous plaques, and yet seem to have
no influence whatever in the localization of caries. A plaque, to
have any considerable effect, certainly must have sufficient firm-
ness in the moist state to act more or less perfectly as a dialyzing
membrane.
In the technical sense, Dr. Williams' work was beautifully
done, and there is no doubt that caries was shown under the
aggregations of organisms in many of his photomicrographs.
Three of these, Figures 156, 157, 158, are reproduced from the
Dental Cosmos, of 1897, by permission.
SlALO-SEMEIOLOGY.
Dr. Joseph P. Michaels, of Paris, presented a brochure
under the above title to the International Dental Congress,
Paris, 1900, which has been translated into English and published
in the office of the Dental Cosmos, 1902.