Page 29 - My FlipBook

surface lightly—it is not necessary for you to hurt your pa- ;
tient at all—go lightly about it and see that there is no decay.
You have perhaps observed that there is only a small portion
of the surface of each tooth that is liable to the beginnings of
decay. Much the greater portion of the surface of each tooth
is immune to the beginnings of decay. Upon the occlusal
surfaces, which we have just examined, decay begins only in
the pits and fissures ; all the rest of the surface is kept clean
by the efforts in mastication. If we examine the buccal sur-
faces—I usually include the pit in the buccal surfaces of the
molars when examining the pits and grooves in the occlusal
surface—it is only the gingival third of the buccal surface in
which decay is liable to begin ; all the rest of the surface is
kept clean by the friction of mastication and decays do not
begin there. So that if you pass your instrument carefully
over the gingival third of the buccal and labial surfaces you
will have covered all of the surface that is liable to decay and
will have found any cavities that are Hkely to be present.
Now when you have done that you will take your mouth
mirror and go around the lingual surfaces the same way,
next to the gums ; just pass your instrument gently about
them, and if there is a point of softening of the surface the
sharp point will catch. It is somewhat rare that we find decay
beginning upon lingual surfaces, but in making the examina-
tion they should not be overlooked. They do sometimes be-
gin there.
After you have finished the examination of the upper
jaw you will change the position of the patient for the ex-
amination of the lower, but whether you will do that before
examining the proximate surfaces will be a question. I
often will change the position of the patient and make this
examination of the buccal and lingual surfaces before
I make the examination of the proximate surfaces, but
that is not so very important ; it will depend a good deal on
circumstances. In examining the proximate surfaces of the
teeth you will use the two curved explorers ; they are rights
and lefts, or double-plane instruments. This is the most dif-
ficult examination for caries that we have to make, and mis-
takes occur oftener in this than in other examinations. Mis-
takes occur in the examination of the buccal surfaces where
you fail to pass your instrument really over the surfaces

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