A crown is a cap made to fit over a tooth that has lost too much of itself to hold a filling: after a large cavity, a crack, a root canal, or years of wear. A bridge uses crowns on the teeth either side of a gap to carry a replacement tooth between them. Both are made in a laboratory to fit your mouth and are cemented in place; neither is removable.

Who it is for, and when it is considered

A crown is considered when a tooth is weakened: a filling that keeps breaking, a cusp that has fractured, a tooth that has had root canal treatment (back teeth in particular, which crack without one), or a tooth that is badly worn or discoloured. A bridge is considered for one or a few missing teeth where the neighbouring teeth are sound and would benefit from crowns anyway, or where an implant is not wanted or not possible.

What the assessment decides

The examination and an X-ray show how much sound tooth remains, whether the nerve is healthy or the tooth needs root canal treatment first, whether the root and the bone around it can carry the load, and, for a bridge, whether the neighbouring teeth are strong enough to support it. That decides whether a crown is the right answer or whether a large filling, an onlay (a partial crown that covers less tooth), an implant or a denture would serve you better, and which material suits the position: all-ceramic or zirconia where appearance matters most, metal-ceramic or metal where strength under heavy biting matters more. You leave with a written plan and an estimate.

What happens, stage by stage

Stage	What is done	Typical interval
Assessment	Examination, X-ray, written plan	First visit
Preparation	Any root canal treatment or gum treatment needed first	Before the crown
Shaping	Under local anaesthetic the tooth is shaped to make room for the crown; an impression or scan is taken; a temporary crown is fitted	One appointment
Laboratory	The crown or bridge is made to the impression	Usually one to two weeks
Fitting	Fit, bite and shade checked; the crown cemented	One appointment
Review	Checked at routine check-ups	Ongoing

What it involves for you

Shaping is done under local anaesthetic and the tooth may be sensitive for a few days afterwards. The temporary crown is for looking after rather than testing: avoid sticky food on that side, and if it comes off keep it and call. Once the final crown is fitted it is cleaned like any other tooth, with the gum line around it and, for a bridge, the space beneath the replacement tooth cleaned with floss threaded underneath or an interdental brush.

The alternatives

A large filling or an onlay keeps more of the natural tooth and costs less, where enough tooth remains to hold it. For a missing tooth, an implant does not touch the neighbouring teeth, which is its main advantage over a bridge, at greater cost and time; a denture is the least invasive option. Extraction is sometimes the honest answer for a tooth with too little left to crown. The dentist will say which of these applies rather than default to the crown.

Questions people ask

How long does a crown last? Commonly ten to fifteen years, often longer, depending on the material, the bite and how the gum line around it is kept. The tooth underneath can still decay at the margin, which is why check-ups continue.

Will it look like my other teeth? Shade is matched to the teeth beside it, and all-ceramic crowns have no metal to show at the gum. The crown is judged in your mouth at the fitting before it is cemented.

My crown came off: is that an emergency? Not usually, if the tooth is not painful, but the tooth underneath is softer than it looks. Keep the crown clean and dry and book within a few days; it can often be re-cemented. The broken tooth or lost crown page says what to do meanwhile.

Cost

Depends on the material, the number of units (a three-unit bridge is three crowns’ worth of work), and whether root canal or gum treatment is needed first. Your written estimate follows the assessment.

Crowns and bridges