Page 154 - My FlipBook

the contact point, and spreading out from that, become mat-
ters of the utmost practical importance to you in your future
operations ; the position of the gum septum is important, for
any portion of a tooth's surface that is covered by heaUhy
gum tissue is immune to decay, consequently this interproxi-
mate gum tissue that fills the interproximate space renders
that interproximate space immune to decay so long as it is
perfect ; hence the extreme care that should be exercised to
keep the interproximate gum tissue in health. A gelatinous
plaque never forms under a healthy free gum margin ; it may
form close to the free gum margin and is prone to form close
to the free gum margin, if it is in a position that is not cleanly,
but it never forms under a healthy free gum margin. But in
this position, the contact point being here, just gingival of
the contact point (indicating), when the gum tissue does not
quite fill to the contact point, is the point most hable to de-
cay on the proximate surfaces of teeth. Then if we can keep
our patients with healthy gum tissue, and the interproximate
space well filled with gum tissue, we do much to prevent the
occurrence oi decay in these surfaces. If on the buccal sur-
faces of the teeth we can teach our patients to keep them
sufificiently clean, we will prevent decay upon those surfaces,
for the reason that the brush or the means used to keep them
well cleaned will tear off and destroy the gelatinous plaques
as rapidly as they are formed.
Now I want to repeat that again. In order that decay
may begin, it is necessary that micro-organisms grow and
become attached to the tooth in these certain sheltered locali-
ties, and that they cover themselves in with a gelatinous cov-
ering that will prevent the dissipation in the saliva of the
acids they form and hold them in contact with the enamel.
It makes no difTerence whether the saliva is acid or alkaline,
so far as decay of the teeth is concerned. People immune to
decay may arrive at middle age, with their saliva continually
showing an acid reaction to tests. Some years ago when the
dentists of the whole Mississippi valley, and of the whole
United States, we might say, were carrying boxes of litmus
paper in their vest pockets and testing the saliva of every-
body with whom they came in contact, trying to determine
these points, we found that the condition of acidity was no
index to the rapidity of caries of the teeth. Those immune
to caries had the same acidity of the saliva as those in whom

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