Rensselaer Union, Volume 6, Number 20, Rensselaer, Jasper County, 5 February 1874 — Dentistry. [ARTICLE]

Dentistry.

It has been charged against our brethren of the dental specialty, says the Lanett, that they are wofully at fault in regard to knowledge of the commonest of all things—caries of the teeth. That they extract teeth with skill, and stop them with even niore skill, and in a nobly conservative spirit, is admitted; but the causes of decay’ in the teeth have remained obscure. The investigations of i> Leber and Rottcnstein into tips subject have at least the charm of'pointing to definite conclusions. -They admit, of course, that there are differences of teeth, constitutional and connected with racey making teeth more or less resistant to "the great influences which determine decay. These are not, according to these authors, internal and vital so much as external and chemical. The process of decay begins from the surface, it is entirely controlled. The great causes of caries are two, namely, acids and a certain fungus found adundantly in the mouth, leptotkrix ouccalis. This latter agent is characterized by certain microscopic appearances and by its reaction with iodine and acids, which give to the elements of leptothrix a beautiful violet tinge. Under the microscope the fungus appears as a gray, finely granular mass or matrix, with filaments delicate and skiff, which erect themselves above the surface of this granular substance so as to resemble an uneven turf. The fungus attains its greatest size in the interstices of the teeth. No one can deny nowadays the action of acids on the teeth, even weak acids, in dissolving the salts of the enamel and the dentine. All acids, both mineral and vegetable, act promptly on the teeth. Various experiments as to the action of acids on dental tissues are given, making the enaihel, naturally transparent, first white, opaque, -and. milky. and, in a more ad vanced state, chatkyTTmd then the dentine

more transparent and softer, so as to be cut with a knife. The acids which may actually effect the first changes in the production of caries are such" as are.taken with food, or in medicines, or such as are formed j in the mouth itself by some abnor- | mality in our secretions, which j should be alkaline, or by afi7 aeid" fermentation of particles of food. But acids alone will not account for al) the phenomena of caries in the teeth. They phiy’--a primary and , principal part, making the teeth porous and soft. In this state, the i tissues having lost their normal : consistency, fungi penetrate both the canaliouli of the enamel and of ' the dentine, and by their prolific ac- ' tion produce softening and destrueI tive effects much more rapid than j the action of acids alone is able to accomplish. It is not pleasant to think that fungi exists in the mouths of all bntthevery cleanest of people Bowditch, in examining forty per- , sons of different professions, and living different kinds of life, found in almost all vegetable and animal parasites. The parasites were numerous in pjjopotivm to the neglect of cleanliness. The means ordinarily employed to clean the teeth had no effect on the parasites, while soapy water appeared to destroy them. If this be-a true version of the causes of caries—the action of acids, supplemented by the action of fungi—then it follows that the great means of pieserving teeth is to preserve the most scrupulous cl‘hnliness of the mouth and teeth, and to give to the rinsing liquids a slightly alkaline character, which is done by the admixture of a little soap. This is not so pleasant a dentrifrice as some, but it is effective and scientific. Acids not only dissolve the salts of the teeth, but favor the increase of the fungi of the mouth. No increase of fungi and no action on the dental tissues occurs in solutions slightly alkaline, such as a weak solution of soap. The good effects of stopping teeth, in the light of these experiments, are intelligible. The penetration of acids and fungi is prevented.— Scientific American,