How is a bridge different from a crown?

A bridge differs from a crown in that a bridge usually spans a space where a tooth is missing. A crown is a single tooth restoration while a bridge is a multi-tooth restoration.

What are dental crowns?

Dental crowns are full coverage restorations that cover the surface of a tooth that usually is above the gingiva (gums). Years ago, crowns were made of gold casting or temporary copper or stainless steel preformed crowns. The crowns were used to cover teeth that had fractured, or broken down because of decay. After the teeth were restored with metal (amalgam) the restoration might have been too large to expect the tooth to function without further fracture or deterioration. A crown was placed to protect the restorations from further breakdown and to strengthen the tooth, so it could function properly with confidence that it would be strong enough to withstand the occlusal forces of mastication (chewing). In more recent years the dental crown has become a cosmetic restoration including the use of resins and porcelain to provide tooth colored restorations. The resins and porcelains were bonded to metal copings to strengthen the crown. Today, many dentists and patients feel that the metal is not as necessary as in previous years and feel that the newer porcelains and resins used today have better color charactistics when formed without the metal coping.

When is a crown necessary?

A crown is necessary when a tooth fractures or has broken down and cannot be rebuilt with materials that can restore its proper appearance and will not be strong enough to function without fear of future fracture.

How long will a crown last?

A crown will usually last many years. Before the decision is made to place a crown over a tooth, the tooth should be evaluated to determine that it will be strong enough to support the function and desired length of time expected. If the tooth is not maintained with proper dental hygiene and develops recurrent decay the crown may not last because the tooth has failed.