Dental Crowns & Bridges

A crown is a cap that covers the whole of the visible part of a tooth and takes the biting force through itself instead of through the remaining tooth walls. A bridge is a set of joined crowns that spans a gap: the teeth on either side are crowned, and a replacement tooth is carried between them.

Both are made in a laboratory from an impression or a digital scan of the prepared tooth, so both take two visits and a gap of a week or two in between. The materials differ in appearance and strength: metal-ceramic, full ceramic, zirconia and gold each behave differently and your dentist will match the choice to the tooth's position and to how hard you bite.

One thing to understand before agreeing. Preparing a tooth for a crown means removing an outer layer of it all round, and that cannot be undone. For a bridge, the same is done to the healthy teeth either side of the gap. Your dentist will go through what that commits you to before any drilling starts.

Both visits are done in the dental chair under local anaesthetic, as a day procedure.

At the first appointment the tooth is numbed and shaped all round with a fine drill, to a depth that leaves room for the thickness of the crown material. Any decay is removed and the tooth is built up underneath where it is missing substance. An impression or a digital scan is then taken of the prepared tooth and of the opposing bite, the shade is matched against your other teeth in natural light, and a temporary crown is cemented on to protect the tooth. This visit takes roughly 45 to 90 minutes, and longer for a bridge.

The laboratory work takes about five to ten working days. At the second appointment, usually 20 to 40 minutes, the temporary is removed, the crown is tried in and checked for fit, contact with the neighbouring teeth, shade and bite, and is then cemented. The bite is checked again with you tapping and grinding, and adjusted until it feels even.

There is no recovery period in the usual sense and you leave able to use the tooth.

A tooth that still has a living nerve is commonly sensitive to cold and to biting for a few days, and occasionally for two to three weeks, as the pulp settles after preparation. This eases steadily. Avoid very hard or sticky food for the first 24 hours after cementing.

While the temporary crown is on, keep off sticky food, chew on the other side, and when flossing that tooth pull the floss out sideways instead of up, so the temporary is not lifted off. If it does come off, it needs recementing promptly, since the neighbouring teeth drift within days and the permanent crown will then not seat.

One thing to act on instead of waiting out: if the bite feels high or the tooth is the first to touch when you close, return to have it adjusted. A high crown causes lasting soreness and can crack the tooth.