What are crowns?
A dental crown is a restoration that covers or caps all exposed surfaces of a tooth when decay, trauma, or pathological wear has damaged the structure of the tooth. Crowns may be fabricated from a variety of materials, including porcelain, metal, and combinations.
Why are teeth crowned?
Once tooth structure is compromised, it is important to support the remainder to avoid further breakdown which could render the tooth non-restorable. In other words, applying a crown can actually save the tooth by protecting the base and root. Indications for a crown include teeth with very large fillings, fractured or broken teeth, or teeth that have had root canal therapy. The main function of a crown is to support the remaining tooth structure by directing biting forces down the long axis of the tooth where the energy is dissipated in the maxilla and mandible.
What is the procedure?
In preparation for a crown, the tooth is reduced dimensionally to allow proper thickness for the restorative material. The amount of tooth removed varies depending on the type of crown material chosen. Restorative materials can range from porcelain, E-max (lithium disilicate), or Procera (ceramic over alumina or zirconia), to non-precious metal, gold, or a combination of metal and porcelain. Each material is appropriate for a specific situation – the one chosen will depend on aesthetics and wear properties desired by the patient and clinician. A crown is then designed to perfectly fit the patient’s bite, and is cemented into place.
How long will a crown last?
The longevity of a dental crown varies from patient to patient. Conditions which can markedly decrease the durability of a crown are pathological biting habits such a grinding and clinching of the teeth (bruxism), increased exposure to food and drinks with high acidic properties, and poor hygiene. With good oral hygiene, proper nutritional choices, and normal biting habits a crown will last for many years – from five to 45, with an average crown life of at least a decade.