A crown is an artificial restoration that fits over the remaining part of a prepared tooth, making it strong and giving it the shape of a natural tooth. A crown is sometimes known as a ‘cap'. Crowns can be made of a variety of different materials and new materials are being introduced all the time. Here are some of the most popular options:
Porcelain bonded crowns: these crowns are made of a metal base with porcelain cover on top making it look like a tooth.
All-ceramic crowns: Emax is a modern material and is metal free giving excellent aesthetic look. This makes it suitable for use in all areas of the mouth.
Gold alloy crowns: gold is one of the oldest filling materials. Today it is used with other metals to increase its strength, which makes it a very hard-wearing restoration. These crowns are silver or gold in colour.
What is a crown?
A crown is an artificial replacement for the outer portion of a tooth and is sometimes known as a ‘cap’. It is suitable for heavily discoloured, broken-down, root canal or weak teeth. An ‘onlay’ is similar to a crown protecting weak parts of the tooth but some of your tooth is visible.
What is it made from?
There are several possible materials. The simplest and cheapest is a silver coloured non-precious metal alloy, used on back teeth within the NHS.
Porcelain fused to metal gives most of the strength of a metal crown, with a more natural appearance.
Porcelain (metal-free) come in various types such a zirconia which are extremely strong and E-max crowns which have the best aesthetics and look very life-like.
How long do crowns last?
A lot depends on the strength of the underlying tooth, your diet and how well you clean your teeth. Research shows a success rate of 95% at 5 years, 75% at 10 years and 50% at 15 years. A lot of crowns made in this practice in the early 1980s are still giving good service.
Does a post have to be put into the tooth to support the crown?
Only if the tooth is already root filled and lacks sufficient tooth structure, then a post will be needed.
Can crowns come out?
The great majority of crowns don’t, but a crown on a very short or tapering tooth lacks resistance to displacement by sticky food, especially toffee! It can usually be re-cemented. Crowns supported by posts are at greatest risk of displacement.
What do I have on my tooth while a crown is being made?
A temporary crown will be fitted, using soft cement to make it easy to remove. It may not be a perfect match, but it’s only for a couple of weeks.
Will it match my teeth?
We can choose from a range of standard shades, but if your teeth are difficult to match you can visit the laboratory so that the technician can see for himself.
Can a crowned tooth still decay?
The crown itself can’t, but decay can start in the tooth beyond the margin of the crown. Proper daily cleaning and a sensible diet will prevent this.