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CHAPTER IV

PRELIMINARY TECHNICAL PROCEDURES

(Continued)

SEPARATION OF THE TEETH—EXCLUSION OF
MOISTURE—USE OF THE MATRIX

Separation of the Teeth

Nature has designed two forms of contact between

approximating teeth—one, the small marble contact, the
ideal form—the other the broad contact, far from ideal, and
found usually in connection with thick-neck teeth.
The contacts are situated at the points of the V-shaped
inter-proximal spaces, which latter are normally filled with
gum tissue. In cases of bell-crowned teeth and marble

contact points, which are the ideal forms, the base of the
inter-proximal V is broad, the proximal surfaces of the teeth
forming the V receding well away from each other. With

thick-neck teeth and broad contact surfaces, the inter-proximal
space is much narrower, the base of the V being very short.
As a result of age and inter-proximal wear, the contact
points are frequently worn flat, with the result that the teeth
have drifted together and the total length of the arch has

been shortened, thus lowering the power of the entire masti-
cating machine. The same conditions are likely to occur
from improper inter-proximal dental operations with inade-
quate contours and contact point restorations. The dentist

should be careful in every instance, where proximal fillings are
made to see that the teeth are lifted apart, through adequate
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