Page 101 - My FlipBook

ABRADED SURFACES. OCCLUSAL AND IXCISAL 97
bible built high "with gold, preferably an alloy of gold, either
platinized foil or a cast inlay of gold alloy.
This Early Restoration of cusps to their full height Avill tend to
restrict the lateral motion of the mandible in mastication, Avhich
seems to be a factor in this dissolution.
Cavity Preparation. These cavities should be prepared as class
cue and should 1)0 retentive throughout.
If the Major Portion of the Occlusal Surface of a single molar is
affected the whole occlusal surface should be lowered about one milli-
meter and the same restored with a cast inlay, sometimes termed
an onlay. This is advised from the fact that the occlusal side of
the filling may better fit the surface of the occluding teeth. This
may and probably Avill necessitate the devitalization of this in-
dividual tooth Avhen the pulp chamber should be utilized for an-
chorage.
If Contact Points have lieen reached by this cutting, a mesio-oc-
clusio-distal cavity is imperative.
When Wear is General opening the bite to the extent of about
one millimeter is preferable to cutting away any more tooth sub-
stance than is necessary for firm foundation and a correct outline.
With Incisal Abrasion, if the wear is not excessive, the building
on of the "shoe," or covering the entire incisal end of the tooth
with platinized gold is the best practice. The gold inlay, which is
ti'eated in the chapters on inlays, is also of service.
When there is excessive incisal wear opening the ])ite to practi-
cally normal is indicated, using gold for the posterior teeth and
the porcelain crown for the anterior.
The Entire Enamel Edge on the occlusal and incisal surfaces
must be covered with a protecting layer of metal as with these
teeth the bond of union seems to be A'ery weak, particularly at
the dento-enamel junction, and they will chip away if not wholly
protected from the force of mastication.