The following Dental information pages answers many of your questions on
crowns, bridges, fixed partial dentures, bonded bridges and cantilever bridges.
What are fixed partial dentures?
As the name suggests, fixed partial dentures or FPD are tooth replacements
that are fixed permanently in the mouth and cannot be removed for routine
cleaning by the patient. These dentures are made to take support from adjacent
natural teeth. Unfortunately these dentures can replace only a few missing
teeth. When a large number of teeth are missing one has to go in for a removable
partial denture or RPD.
What are the types of fixed partial dentures?
Fixed partial dentures are of various types. They can be made of porcelain
or metallic alloys. The metallic FPD's are made of either gold alloys or
chrome cobalt alloys.
What is a crown?
A crown is a restoration that covers the entire tooth like a cap. It can
be made of porcelain or acrylic. Crowns are used to restore teeth that are
discolored, have multiple decays or are fractured.
What is a bridge?
A bridge is a prosthetic appliance that replaces missing teeth by permanently
getting attached to the adjacent remaining teeth.
What are metallic FPD's?
Metallic FPD's are fixed partial dentures that are made of metal alloys
such as gold alloy or chrome cobalt alloy. The metallic FPD's are used mostly
in the back teeth, as they are not esthetic in appearance. In case esthetics
is important the metal crowns can be given an acrylic or porcelain facing
over the areas that are visible to the exterior so as to make them esthetically
Can metallic bridges be made to look more esthetic?
The metallic FPD's can be given an acrylic or porcelain facing over the
areas that are visible to the exterior so as to make them esthetically acceptable.
Is it pure gold that is used?
Earlier pure gold was used in the fabrication of FPD's. The higher cost
of gold and its softness led to the introduction of the gold alloys, which
have some % of gold along with other metals such as platinum, palladium,
silver, copper, zinc, etc. These additions to the gold made the alloy cheaper
and also improved its mechanical properties. A number of different gold-based
alloys are available with differing contents of gold that are used for different
How many teeth can be replaced by a bridge?
The maximum number of teeth that can be replaced by a bridge is two to
three. Much depends upon the health of the remaining teeth and in which
area the teeth are missing.
What is a cantilever bridge?
Unlike a normal bridge that is attached to teeth on both sides, a cantilever
bridge is one that is attached only on one side to the remaining teeth.
The other side is free or unattached. These cantilever bridges are indicated
when the tooth to be replaced is the last one and does not have remaining
teeth beyond it. These bridges have poor prognosis in the long run.
What are bonded bridges?
The resin bonded fixed partial dentures are those that are bonded to adjacent
teeth using acrylic resins. Unlike the conventional bridges these resin
bonded ones need less reduction of the adjacent remaining teeth and are
therefore more conservative.
Can a root be used to give support for a bridge?
Sometimes we come across patients who have some roots remaining. These
roots can be used to give support for prosthesis. These roots are first
endodontically treated and then strengthened by inserting a post into their
root canals. Over these posts a core is built up and this core can be used
to give support for the prosthesis. These are called post and cores.