Page 29 - My FlipBook

GREEN TARTAR. Zb

teeth, and only on the anterior surfaces of the super-

ior. The color of this deposit varies from a light
brown to very dark, inclining to green. Wherever
it attaches, the surfaces of the teeth are abraded, and
when it is of long standing, the entire enamel beneath
it is destroyed, and the dentine is gradually involved
in the dissolution. This effect upon the teeth is not
produced by the coloring matter observed upon them,
but by an acid in combination with this material
before it is deposited. The stain is a precipitate
from this compound, and the acid, leaving this, com-
bines with the calcareous ingredients of the teeth, to

their detriment as above; but the precipitate is en-
tirely innocent.
Its Origin.—Green tartar, or green stain, doubtless
has its origin in the mucus, when this is in a particular
acid condition. That it does not proceed from the
saliva is proved by the fact that it is never found
where there is a free flow of saliva, or where it has

free access; but the point of its deposit is where
the saliva is least frequently present, being most
abundant in cases in which there is a large relative
amount of mucus, and this in a very acid condition.
But the query might arise here, if the mucus of the
mouth were wholly in that condition, why would not
the teeth suffer from it elsewhere. Because, on the
masticating surfaces of the teeth, the friction of the