A crown is a bit like a special thimble made of metal or porcelain, or both, that covers a damaged or weak tooth, which gives it added strength. Your dentist will match it up to the shape – and, in the case of porcelain crowns, colour - of your other teeth so it will look natural. The crown will probably last for many years, depending on the health of the tooth underneath.

The dentist will prepare the tooth by removing some of the surface. This is done so that, when the artificial crown goes over the tooth, it will be the same size as normal. Preparation time will depend on how damaged the tooth is and whether it needs to be built up with a filling first. The tooth might have to be root-filled first - some people call this 'removing the nerve'. The crown is sometimes held in place by a peg in the root canal if a lot of the tooth is missing.

Your dentist will then take an ‘impression’ of the tooth. A soft putty-like material is used to do this. The material sets in your mouth, giving a very accurate mould of the tooth to be crowned and of the teeth nearby. Sometimes thin cord may be used to hold the gum away from the tooth so that the impression is accurate round the edges. Then a dental technician uses the impressions to make the crown the exact height and size needed. A temporary crown made of plastic or metal is put over the tooth until the permanent crown is made. You can chew on a temporary crown but it won't be as strong as the finished one. When the finished crown is fitted, your dentist will make small adjustments to make sure you can bite comfortably. The crown is “tried on” first, and then glued into place.