Dental Crowns
Some examples of dental crowns and bridges, shown before they are bonded to the teeth
A dental crown is somewhat like a hat or cap that is fitted over the top of a weakened or damaged tooth. It helps to keep the tooth and its internal fillings from breaking and can help the tooth to last for a longer period of time than it otherwise might.
Crowns can be made of gold, metal, porcelain or a combination. The type of crown used in each case is influenced by your preference and the circumstances facing each tooth.
When Does A Tooth Need A Crown?
If a tooth has been heavily filled, deeply decayed, chipped, cracked, weakened or is bearing heavy chewing pressures, Dr Teo may recommend a crown. Sometimes a tooth might be crowned for cosmetic reasons, to improve its appearance.
Can A Crown Fix Any Damage To A Tooth?
Unfortunately not. Some teeth are so badly damaged by decay or fracture that they are simply not salvageable.
A dental crown only deals with the external part of the tooth, by protecting it from further damage, encasing it to try to prevent further fractures of the tooth and filling(s) in it. Teeth requiring crowns usually have had large, deep fillings (often placed as a result of deep dental decay) which are close to the nerve. The crown is unlikely to reverse any damage that may have already been done to the internal nerve (also know as the dental pulp). Sometimes the nerve dies, and the tooth becomes painful. In these cases, root canal therapy may be required. Learn more about Root Canal Therapy here.
While crowns themselves cannot decay, the tooth structure underneath them can, so your crowns must be cleaned carefully and thoroughly every day. Fortunately this is usually as easy as cleaning your natural teeth: brushing and flossing regularly are the key.
Dental Bridges
A dental bridge is used to fill a space between two teeth where a natural tooth used to be. To learn about other ways of replacing missing teeth, click here.
When Are Bridges Used?
A bridge consists of two crowns with an artificial tooth (called a pontic) suspended between them. The crowns are cemented or bonded to the teeth on either side of the space, and these hold the pontic in the space, effectively replacing the missing tooth.
Bridges are most often used if the teeth on either side of the space are heavily filled or weakened and are likely candidates for a dental crown. The bridge thus has three functions: it protects the adjacent teeth and replaces the missing one. If the adjacent teeth have never been filled or only have small fillings, an implant or a Maryland (bonded) bridge may be recommended instead.
A bridge might also be placed in areas where there is not enough bone to support a dental implant.
Taking Care Of Your Crowns And Bridges
Bridges must be kept very clean to reduce the chances of decay in the underlying teeth and to avoid gum disease around either of the supporting teeth. You will be shown how to clean under the bridge using special floss or interdental brushes.
How Long Do Crowns And Bridges Last?
The lifespan of a dental crown or bridge will depend on many factors, including the quality of home care they receive, what foods and beverages you consume, the number and type of injuries that occur (for example, sporting injuries) as well as whether or not they bear heavy biting forces such as grinding.
Generally, well-looked after crowns and bridges can remain in the mouth for many years, even decades. Improvements in technology and materials are likely to produce even longer life spans for crowns and bridges in the future.