Over time, your teeth can become damaged. This can happen for a variety of reasons, such as decay, trauma or simply as a result of prolonged use. Your teeth may lose their shape or size. A dental crown is a tooth-shaped "cap" that is worn over the tooth to restore the shape, size, strength and appearance of the tooth.

A dental crown is attached to the tooth and covers the visible part of the tooth.

Why do I need a Dental Crown?

You may need a dental crown for several reasons, including:

To protect a weak tooth (possibly from decay) from decay or to hold a weak tooth together if parts of it have cracked.

Repairing a broken tooth or a badly worn tooth.

Covering and supporting a tooth with a large filling and a small amount of remaining tooth.

Holding a dental bridge in place.

Covering irregularly shaped or severely discoloured teeth.

Covering a dental implant.

Covering a tooth that has been treated with a root canal.

What are Dental Crowns made of?

Permanent crowns can be made from different materials. These materials may include:

Metal: There are several metals that can be used in dental crowns including gold, palladium, nickel and chrome. Metal crowns rarely chip or break, last the longest and require the removal of only a small part of the tooth. They can also withstand biting and chewing.

Porcelain-fused-to-metal: This type of crown can be matched to the colour of the teeth next to the crown. They have a more natural tooth colour.

All Resin: Resin bonded dental crowns are usually less expensive than other types of crowns. However, over time they will wear out and break more often than crowns made of porcelain and metal.

All-ceramic or all-porcelain: These types of crowns provide better colour matching than other types of crowns. They are also a good choice if you are allergic to metal. However, they are not as durable as porcelain-fused-to-metal crowns.

Pressed ceramic: These dental crowns have a hard inner core. Pressed ceramic crowns replace the metal inlay used in all-ceramic crown manufacturing. Pressed ceramic crowns are coated with porcelain, which provides the best natural colour combination. They are also more durable than all-ceramic crowns.

How is my tooth prepared for a Dental Crown?

During the first visit, the tooth to be crowned is examined and prepared. X-rays are taken of the tooth and the bone tissue around it. Your dentist may have to treat a root canal, if any, before a crown is fitted:

• Risk of infection.
• Damage to the tooth's pulp.
• The pulp is the soft tissue inside the tooth containing blood vessels, nerves and connective tissue.
• The tooth on which the crown will be placed will be shaved from the top and sides. This will make room for the crown itself. The number of teeth that will be prepared depends on the type of crown.
• After the tooth is reshaped, paste or filler is used to make a copy (also called an impression) of the tooth on which the crown will be placed. Impressions are also taken of the teeth above and below the tooth on which the crown is to be placed. This is done to make sure that the crown will not affect your bite.
• During the second visit, a permanent crown is placed on the tooth. First, the temporary crown is removed and the fit and colour of the permanent crown is checked. If everything is OK, the new crown is fixed in place.

What type of anaesthesia is used for the crown insertion procedure?

Sometimes a local anaesthetic ("numbing") is used to anaesthetise the tooth.

How long do dental crowns last?

The average lifespan for a well-maintained dental crown is typically around 15 years. However, when taken care of properly, it is common to see them last upwards of 25-30 years.

What problems can occur with a dental crown?

Discomfort or sensitivity. Your tooth with a new crown may be sensitive immediately after the procedure, as the anaesthetic begins to wear off. If there is still nerve in the tooth covered by the crown, you may experience some sensitivity to heat or cold.

Loose crown. Sometimes the cement is washed out from under the crown. This not only allows the crown to loosen, but also allows bacteria to infiltrate and cause decay in the remaining tooth. If the crown feels loose, go to a dental office.

The crown falls off. Sometimes crowns fall off. Causes are decay of the underlying tooth and weakening of the cementitious material used to fit the crown.

Allergic reaction. Since the metals used for crowns are usually a mixture of metals, an allergic reaction to the metals or porcelain used in the crowns may occur, but it is very rare.

A dark line on a tooth with a crown near the gum line. A dark line near the gum line on a tooth with a crown is normal, especially if you have a crown made of porcelain fused to metal. This dark line is simply the metal of the crown. Although this line itself is not a problem, it is cosmetically unacceptable and your dentist may have to replace the crown with an all porcelain or ceramic one.