Page 34 - Amazing Smiles

CHAPTER THREE figure 31
figure 31b
be removed with a dental drill so that a full tooth
covering can be made. (figure 31)

There are general techniques for fabricating
crowns. One type of crown has a metallic core
inside covered by a thin layer of porcelain. It is
held in place by dental cement. This is called a
“porcelain fused to metal crown.” (figure 31b).
When the inner core is gold, it is called a “porce-
lain fused to gold crown.” When porcelain fused
to metal or gold crowns is used, the metal inside
the crown must be covered with an opaque line.
The opaque prevents the metal color from show-
ing through the translucent porcelain. However,
opaque layers affect the color quality of these
types of crowns. They often look too harsh or
“dead” because of their poor reflective qualities
and lack of translucency. If the crown cannot be
seen when smiling, it can be made entirely of
metal, such as gold. However, for the purpose of
this book we will concentrate on cosmetically vis-
ible crowns, as their esthetic requirements are
different. Generally speaking, porcelain fused to
metal crowns are stronger than all porcelain
crowns. However, with new advances in porcelain
technology, all porcelain crowns may, prove to
be, be just as strong as traditional porcelain fused
to metal crowns.

The greatest advantage of all porcelain
crowns is that they look more natural in the
mouth. This is due to the fact that light transmits
through the porcelain, similar to a natural tooth.
When porcelain fused to metal crowns are used,
the metal inside the crown must be covered with
an opaque to block it out then a thinner porcelain

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