If your tooth is damaged but not lost, a crown can be used to restore its shape, appearance and function. You may need a crown if you have a root canal, a large filling in a tooth or a broken tooth.
A crown, also called a cap, is a hollow, artificial tooth used to cover a damaged or decayed tooth. The crown restores the tooth and protects it from further damage. Crowns can also be used to cover a discoloured or misshapen tooth. A tooth that has been fixed with a crown looks and works very much like a natural tooth.
How a crown is done
Your dentist gives you a local anesthetic. To make room for the crown, your dentist files down the tooth that needs to be restored.
An impression of the filed-down tooth and nearby teeth is taken. This impression is used to custom make your final crown. The crown is built using restorative material (material used for fillings) based on the impression. The final crown will be the right shape for your mouth.
Until your final crown is ready, your dentist places a temporary crown over the tooth that needs to be restored. The temporary crown is made from an impression of your tooth before it was filed down. It protects your tooth until the final crown is ready. A temporary crown may not have the same shape and colour as a final crown.
On your next visit, your dentist takes off the temporary crown and puts on the final one. Your dentist checks to make sure the crown is the right fit, shape, colour and bite. If it is, your dentist cements the crown into place.
These are the steps dentists most often follow in making a crown, but your tooth may need special care. You may need orthodontic treatment, gum treatment or root canal treatment. It may take more than 2 visits to your dentist, or your visits may last longer.
Different types of crowns
Crowns are made from various types of materials. Depending on which tooth needs a crown, your dentist will suggest a material, or combination of materials, that is right for you.
Metal crowns are made of gold. They generally last a long time and won’t chip or break. They tend not to wear down your opposing natural teeth. However, the gold colour does not look natural, particularly on front teeth.
Composite crowns look natural. They won’t chip as easily as porcelain crowns, but they tend to wear more quickly from chewing. Tooth brushing tends to remove the highly polished surface of composite crowns and this causes them to stain more easily.
Porcelain crowns look the most natural. They are more brittle than metal or composite and may chip more easily. Because of this, they are not usually placed on back teeth.
Porcelain-fused-to-metal crowns look natural and are stronger than porcelain or composite crowns. They won’t chip as easily as porcelain or ceramic crowns. However, depending on their design, the metal may show if your gums are thin or shrink.
What else should I know about crowns?
Crowns are strong and generally last for about 10 years or longer if you take good care of them. Brush and floss your crown, just like you clean your natural teeth. Crowns may not be as strong as your natural teeth. So like your natural teeth, remember not to bite down on hard objects or use your teeth to open or cut things.