Page 49 - My FlipBook

CARIES OF THE TEETII. 45 ;

tiimally varying in the same person at different ages.
There is a constant change going on, the calcareous
elements increasing, and the animal decreasing. But
a proper relative amount of elements may be elabo-
rated, and yet a defective organization exist. This
condition arises from defective organizing power, or
from a failure in arrangement and combination of the
materials; and is dependent entirely on accidental
causes. In vital energy, indeed, the teeth exhibit
great diversity; and this corresponds with, and to

some extent depends upon, the vital energy of the
general constitution. Dead dentine is decomposed
more readily than living ; and hence the conclusion
that vitality resists caries, and that this resistance
corresponds with the vigor of the vitality.
The points most frequently attacked by caries, are

the proximal surfaces of the teeth, the indentations
and fissures on the masticating surfaces of the molars
and bicuspids, the longitudinal depressions on the
buccal and palatal walls of the molars, and the necks
of the teeth at the termination of the enamel. On the
proximal surfaces, the enamel is thinner than else-
where ; and the situation is peculiarly favorable for
the accumulation and retention of injurious agents.
The union of the enamel in the fissures and indenta-
tions of the crowns of the molars, is often imperfect

and thus there is a way of entrance for vitiated fluids