A dental crown is a tooth-shaped “cap” that is placed over a tooth – to cover the tooth to restore its shape and size,
strength, and 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
What Types of Crowns Are Available?
Permanent crowns can be made from stainless steel, all metal (such as gold or another alloy), porcelain-fused-to-metal,
all resin, or all ceramic.
Stainless steel crowns are prefabricated crowns that are used on permanent teeth primarily as a temporary measure. The crown
protects the tooth or filling while a permanent crown is made from another material. For children, a stainless steel crown is
commonly used to fit over a primary tooth that’s been prepared to fit it. The crown covers the entire tooth and protects it
from further decay. When the primary tooth comes out to make room for the permanent tooth, the crown comes out naturally with
it. In general, stainless steel crowns are used for children’s teeth because they don’t require multiple dental visits to put
in place and so are more cost- effective than custom-made crowns and prophylactic dental care needed to protect a tooth without
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
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 better 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 a lab.
What Steps Are Involved in Preparing a Tooth for a Crown?
Preparing a tooth for a crown usually requires two visits to the dentist — the first step involves examining and preparing the tooth,
the second visit involves placement of the permanent crown.
What Are “Onlays” and “3/4 Crowns?”
Onlays and 3/4 crowns are variations on the technique of dental crowns. The difference between these crowns and the crowns discussed
previously is their coverage of the underlying tooth. The “traditional” crown covers the entire tooth; onlays and 3/4 crowns cover the
underlying tooth to a lesser extent.
How Long Do Dental Crowns Last?
On average, dental crowns last between five and 15 years. The life span of a crown depends on the amount of “wear and tear” the crown
is exposed to, how well you follow good oral hygiene practices, and your personal mouth-related habits (you should avoid such habits as
grinding or clenching your teeth, chewing ice, biting fingernails, and using your teeth to open packaging).