Page 36 - My FlipBook

32 OPERATIVE DENTISTRY
substance is lost through decay in proximal cavities, there is in
most cases a movement of the teeth to the proximal, encroaching
on the normal space, robbing the gum of sufficient room for full
festoon. It is wholly impossible in such cases for the operator in
making a filling to restore tooth contour, or leave a normal amount
of room for the rehabitation of the gum septa, without resorting
to separation. The surfaces of a tooth which are covered with
healthy gum tissue are practically immune from both prim.ary and
secondary caries, and it is greatly to the advantage of a filling, the
outline of which in the proximal gingival third, to be so protected.
Good access should be gained by preliminary separation, so that
when the completed filling with its full tooth-form restoration is
in place, there is restored the normal proximal space for the habita-
tion of the gum septa. A failure to regard this fact Avill result in
a strangulated, diseased and dwarfed septa, inviting an accumula-
tion of the enemy of tooth structure and an early loss of the filling
through secondary caries.
Restoration of Tooth Form is essential that the full function of
the masticating organs may be established and maintained. It is
also desirable for esthetic reasons, as the more nearly a dentist
approaches complete tooth contour restoration, with all its details,
the more pleasing is the appearance and the more artistic the
result.
Proper Contact Point is often impossible unless sufficient ac-
cess has been secured through separation. This contact should
l^e a point of contact, the embrasures widening therefrom in every
direction. It should be in no sense a line of contact or a surface,
no matter how small. It is advisable many times, in this respect,
to improve on nature by slightly varying the surface of the filling
from the original shape of the tooth, as often the predisposing cause
of the primary decay has been defective contact.
The Saving of Tooth Substance is materially effected by access
through preliminary separation, particularly in the placing of in-
lays, as the more thoroughly this first step in procedure has been
accomplished the less cutting will be required for convenience form,
a point of no small importance.
Methods of Separation. There are two classifications of separa-
tion to gain access, preliminary, which is also slow separation, and
immediate, which is rapid, both of which are a part of gaining ac-
cess.
The preliminary is a part of the first consideration, while im-