A dental crown is a tooth-shaped "cap" that is
placed over a tooth - covering the tooth to restore its shape and size,
strength, and/or to improve its appearance.
The crowns, when cemented into place, fully encase the
entire visible portion of a tooth that lies at and above the gum line.
Why Is a Dental Crown
Needed?
A dental crown may be needed in the following situations:
To protect a weak tooth (for instance, from decay) from
breaking or to hold together parts of a cracked tooth
To restore an already broken tooth or a tooth that has been
severely worn down
To cover and support a tooth with a large filling when there
isn't a lot of tooth left
To hold a dental bridge in place
To cover misshapened or severely discolored teeth
To cover a dental implant
What Types of Crowns
Are Available?
Permanent crowns can be made from all metal,
porcelain-fused-to-metal, all resin, or all ceramic.
Metals used in
crowns include gold alloy, other alloys (for example, palladium) or a base-metal
alloy (for example, nickel or chromium). Compared with other crown types, less
tooth structure needs to be removed with metal crowns, and tooth wear to
opposing teeth is kept to a minimum. Metal crowns withstand biting and chewing
forces well and probably last the longest in terms of wear down. Also, metal
crowns rarely chip or break. The metallic color is the main drawback. Metal
crowns are a good choice for out-of-sight molars.
Porcelain-fused-to-metal
dental crowns can be color matched
to your adjacent teeth (unlike the metallic crowns). However, more wearing to
the opposing teeth occurs with this crown type compared with metal or resin
crowns. The crown's porcelain portion can also chip or break off. Next to
all-ceramic crowns, porcelain-fused-to-metal crowns look most like normal
teeth. However, sometimes the metal underlying the crown's porcelain can show
through as a dark line, especially at the gum line and even more so if your
gums recede. These crowns can be a good choice for front or back teeth.
All-resin dental
crowns are less expensive than other crown types. However, they wear down
over time and are more prone to fractures than porcelain-fused-to-metal crowns.
All-ceramic or
all-porcelain dental crowns provide the best natural color match than any
other crown type and may be more suitable for people with metalallergies.
However, they are not as strong as porcelain-fused-to-metal crowns and they
wear down opposing teeth a little more than metal or resin crowns. All-ceramic
crowns are a good choice for front teeth.
Temporary versus
permanent. Temporary crowns can be made in your dentist's office whereas
permanent crowns are made in a dental laboratory. Temporary crowns are made of
acrylic or stainless steel and can be used as a temporary restoration until a
permanent crown is constructed by the dental laboratory.
Above article from: Webmd.com
A crown is a tooth-shaped cover placed over a tooth that is badly damaged or decayed. Many people call it a cap.
