Each of your teeth depends on the others to help you eat and speak, so when one or more is damaged, the health of the others may be threatened. It may become hard for you to chew, or the appearance of your smile may change. If you are having problems with one or more of your teeth, a crown can help restore your mouth to its normal function.
A crown (often called a cap) is an artificial cover that is placed on an individual tooth (somewhat like a thimble over your finger) to restore a decayed or damaged tooth to its normal shape and size. This procedure is often necessary when there is no longer sufficient tooth structure left to place a filling. It is also useful for protecting teeth that are cracked or broken. A crown can be used to change the shape of a tooth, to correct a bite or cosmetic problem, or to replace an existing broken or poor-fitting crown. A crown may be made of gold, other metals or porcelain, which makes them durable and strong, so replacements are needed less often.
Crowning is quite an aggressive form of treatment because the entire tooth surface must be reduced and replaced with an artificial material, but because of its strength and resistance to chewing stress, a crown is functionally superior to other aesthetic procedures.
There are several types of aesthetic crowns. The type of crown you and your dentist choose will depend on a number of factors, including the location of the tooth or teeth being crowned, the type and severity of the discolouration, and the overall health of the surrounding gums.
A Ceramo-Metal Crown
Advantages include: Ceramo-metal is the strongest type of aesthetic crown available; it doesn’t fracture or chip as easily as an alternative aesthetic type crown, and is usually the most economical option.
Disadvantages include: Metal may be visible if tissue shrinks or is thin; metal may affect the colour of the porcelain; and there is a possible bluish tint of gum if gum tissue is thin and metal shows through.
Full Gold Crown
Advantages include: Gold is kind to tissues and gums; it is strong: nothing chips or breaks off, as with porcelain and composite crowns.
Disadvantages include: Not as aesthetic as other crowns.
Porcelain or Composite*
Advantages include: Most aesthetic throughout crown life, and no metal shows.
Disadvantages include: Not as strong as a ceramo-metal crown; margin may be more susceptible to chipping and more costly to make.
*Porcelain and composite crowns are aesthetically similar, except that they are made of different materials. Composite crowns won’t chip as easily as porcelain crowns and wear more evenly with your natural teeth.
Fitting a crown is a 2-step procedure. During your first visit, your dentist prepares and reshapes your tooth by removing enamel and dentin to allow room for the crown. You will be given anaesthesia beforehand. Then an impression of the prepared tooth and surrounding and opposing teeth is taken. Before you leave the office, your dentist will make and apply a temporary crown to protect the prepared tooth between visits.
Expect to wait 1 week between visits while your crown is being made. Meanwhile, take care of your temporary crown by avoiding hard or sticky foods. In the event the crown comes loose, call your dentist so the prepared tooth won’t be damaged.
At your second visit, your dentist removes the temporary crown and fits the permanent crown onto your tooth, making sure it restores your tooth to its proper shape, look and comfort level. If necessary, your dentist may have to adjust the crown by modifying the shape. Once the fit is the way you want, cements are applied and the crown is positioned securely onto your tooth.
If the crown needs further changes, additional visits may be necessary.
Living with Your Crown
Crowns are designed to look and feel like real teeth. As with your original smile, care must be taken to avoid tooth fractures, and with good oral hygiene, your crown will last longer. It is recommended that you:
Brush and floss around your crowned tooth thoroughly to remove decay-causing germs
See your dentist regularly to help prolong the life of your crown
Ask your dentist about special cleaning aids
You should know:
Crowns can fracture
The procedure requires anaesthesia
Original tooth form is altered (possibly involving the nerve)
Crowns are not permanent and may need to be replaced after 5 to 15 years
If tissue shrinkage occurs, it can expose the junction between the tooth and crown, allowing for the possibility of an unsightly line
Crowns may not give the best aesthetic result for people with serious bite or gum problems
The greatest things about crowns are:
Dentist can repair a chipped or fractured tooth
Teeth can be lightened to any shade
Some realignment/straightening of teeth is possible
Crowns can be shaped to aesthetically fill gaps
Crowns offer the longest life of any restoration