A bridge is used where a tooth is missing. The teeth either side of the space are crowned with a false tooth within the space. Bridges are made within a dental laboratory and are then fitted by the dentist.
If a tooth is missing near the front of your mouth the main reason to replace it is cosmetic. If the gap is nearer the back of the mouth and does not show, then the main reason to replace a missing tooth is to avoid problems with the teeth each side of the gap, or in the opposite jaw to the gap.
Teeth only remain where they are in your mouth because they all support each other, if one is lost then commonly the teeth each side of the space start to move into the space and tilt. This can lead to food getting trapped between your teeth and gum disease around the tilted teeth. The way your teeth "bite" may also change. A well-designed bridge will last many years and is a very good method of replacing one or two teeth. They can be made to replace more teeth than this if there are enough teeth in your mouth to attach them to.
If you require a more extensive restoration than a crown or have more than one tooth that needs to be repaired, a good solution is a bridge.
Once you have a bridge fitted, you will have to take extra care during your daily hygiene regime to ensure it stays plaque free and does not cause bad breath.