Dental Crowns- What They Are and When They Are Used

What is a Dental Crown?

There is a branch of dentistry called ‘restorative dentistry’, which is all about fixing teeth or restoring their form (shape) and function. One type of restorative dentistry that most people are familiar with is the dental filling. A filling is a restoration that is used to fill a void (hole or cavity) in the tooth after a dentist removes decay from it. A filling might also be placed if a piece of tooth breaks off.

So what happens when the hole or fracture in the tooth is too big to hold a filling?

This is a situation in which a dentist may recommend a dental crown.

A dental crown sits over what remains of the tooth, usually covering it entirely. Crowns are sometimes also called ‘caps’ because they ‘encapsulate’ the remaining tooth structure. A crown is typically made of metal (generally a gold alloy), porcelain, or a fusion of both: these materials are used because they are strong and resilient to the normal forces of chewing, sometimes even when they are quite thin.

How Are Traditional Dental Crowns Made?

There is quite an art to creating a crown to fit a severely damaged tooth. The dentist often needs to add some material into the cavity first- this is called a core. He or she then refines the shape the tooth and core to be quite parallel on all sides. This shape helps the overlying crown to grip the tooth and core- if the tooth was shaped to be more cone-like, with a broad base and a narrow top, the crown itself would not contribute to the grip, and the dental glue or cement would have to do all the gripping work.

The tooth and core must also to be trimmed to allow the crown to be a certain thickness at the top and sides: this is done to ensure the crown is strong and durable. More thickness needs to be allowed for a porcelain crown than a metal one- this is the reason that sometimes a metal crown is the only reasonable option right at the back of the mouth where space is limited.

Once the tooth has been trimmed and shaped, the dentist then records this shape by using highly accurate impression paste: this is used to create an exact replica of the shaped tooth and core, upon which a talented dental technician builds the crown to be the size and shape of a natural tooth. If the crown is made of porcelain, it can even be coloured and detailed to look like a natural tooth.

(There is another way of creating porcelain crowns that we offer at Corinna Dental called CEREC- we’ll describe this in another article!)

The crown is cemented to the prepared tooth with strong glue, and is polished to fit into the bite and to be easily cleaned. A crown needs to be kept just as clean as a natural tooth, because decay can still start if plaque is allowed to build up around the neck of the tooth. A well-designed crown allows for easy brushing and flossing.

How Long Will A Dental Crown Last?

Many people wonder how long a dental crown will last. Whilst nothing artificial in the body can ever really be considered a permanent fixture, a well-designed and well-maintained crown may well remain in place for many decades.

Make Sure You Understand Your Diagnosis

If your dentist prescribes a crown for one of your teeth, always make sure that you understand why it is necessary. It is your dental professional’s job to help you understand why treatment is needed, what options are available and what the outcome of each treatment option are likely to be. At Corinna Dental, we will always be happy to answer your questions.

While at first a crown may sound like an expensive or unnecessary treatment, you’ll often find that your dentist has recommended it because it is the best way to keep a tooth healthier and functional for longer.