What is a crown?
A tooth has two portions, the root and the crown. The root is below the gum line, and the crown is above the gum line. When the natural crown has broken, worn excessively, is heavily stained, or has large portions destroyed by decay, the tooth needs an artificial crown to restore its original shape and color. The porcelain crown replaces the visible portion of a tooth.
How can dental crowns be used to recover the cosmetic appearance of teeth?
Since a dental crown replaces the visible portion of a tooth, any dental crown that has a porcelain surface can be used to improve the cosmetic appearance of a tooth. However if the teeth only need a color correction, we may decide to use a more conservative treatment to deal with that problem such as porcelain veneers or teeth whitening.
Dental crowns are best utilized as a way to improve the cosmetic appearance of a tooth when the crown simultaneously serves other purposes also, such as restoring a tooth to its original shape (repairing a broken tooth) or strengthening a tooth (covering over a tooth that has a very large filling).
In which cases is it desirable to make a dental crown?
• When a large part of the tooth is missing.
• When the tooth is misshapen or discolored
• When a tooth has had a root canal treatment and needs to be protected from breakage
• When the patient's teeth are very worn down because of severe bruxism
What are dental crowns made of?
They can be made from:
• metal (gold or other metal alloys)
• ceramic materials (such as porcelain)
• a combination of both (Porcelain-fused-to-metal dental crowns).
We will discuss the most appropriate crown for your situation.
Gold crowns have set the standard by which all other crowns have been judged and are still considered to be a functional material for restorations due to their longevity and resistance to breakage and wear. They have been used for centuries, and are biocompatible. They are generally in the back of the mouth, so the tooth doesn't show when you smile.
Full-porcelain dental crowns
These crowns have a translucency and brightness that makes them the most cosmetically pleasing of all of the different types of dental crowns. These crowns are the first options for front teeth. CEREC crowns are our preferred brand.
Porcelain-fused-to-metal dental crowns
In these crowns the core made of metal is surrounded by porcelain. These crowns can be a good option for either back or front teeth. These crowns are very resistant and at the same time can have an excellent cosmetic appearance.
How long can dental crowns last?
The crown's lifespan depends on the environment and forces the crown is exposed to (chewing, biting, accidental trauma, tooth grinding) and how well you keep the tooth to which it is cemented free of dental plaque.
It would be reasonable to expect that a dental crown could last between ten and fifteen years, or even more, if you follow the care instructions. Crowns over implants last longer than crowns over teeth.
When do old dental crowns need to be replaced?
• If it feels loose. This may mean that the crown has decay beneath it.
• If a tooth decay develops at the edge of the crown. If your oral hygiene is not adequate, a cavity can form.
• If the dental crown has become heavily worn.
• If the dental crown has cracked or broken.
• If the aesthetics of the crown have become unacceptable. The most common situations are when a crown's edge has become visible and it has a grey appearance; and when the color of the dental crown no longer matches its neighboring teeth.
How can dental crowns strengthen teeth?
The strengthening capability of dental crowns is related to the fact that when a tooth is missing part of its structure, the tooth is weak. So the crown can act as a splint that binds a tooth together. This is a very important feature of dental crowns and one that makes them a very important type of restoration.
On the contrary, other treatments like big metal fillings can have a weakening effect on the teeth in which they are placed. Dental fillings rely on a tooth's remaining structure to hold and support them. Metal fillings, in general, don't strengthen a tooth and can't protect a tooth from the forces generated by biting and chewing.
On the other hand, repairing a large cavity often requires the removal of so much tooth structure that the overall strength of the tooth is reduced, in some cases greatly. This is because the tooth is no longer as intact as it once was; its structural integrity has been compromised.
In those cases a crown will produce the most predictable successful outcome for your tooth, in the long run.
What is the relationship between dental crowns and root canal treatment?
Some people seem to equate a tooth's need for a dental crown with the need for root canal treatment. While both of these dental treatments may be required they are entirely separate procedures and, most certainly, not every tooth that will have a crown needs a root canal treatment; and not every tooth that needs a root canal treatment needs a crown.
What happens if you don't protect a tooth with a dental crown?
It's impossible to know precisely what will happen in those cases. However, there are some possible situations that might develop for the tooth:
1- The tooth will crack in a fashion that is easily repaired
2- The tooth breaks, but it requires other types of dental work before the dental crown can be made. (Ex: root canal treatment, periodontal surgery, etc)
3- The tooth breaks in a fashion in which it cannot be repaired.
What precautions should be taken with a temporary dental crown?
As temporary dental crowns are held in place by "temporary" cement that is not as strong as other types of dental cement, you have to take some precautions so as not to dislodge it.
* Minimize the usage of the side of your mouth that has the temporary crown.
* Keep sticky foods away from the temporary dental crown.
* Avoid chewing hard foods with the temporary dental crown.
A tooth with a temporary dental crown can usually be brushed and flossed in normal fashion, with the following consideration. After flossing it may be best to remove the dental floss by way of letting loose of one end and then pulling it out to the side. Pulling the floss back out in normal fashion might snag the temporary crown and pull it off its tooth.
If your temporary dental crown does happen to come loose you should contact your dentist's office so they can provide you with specific instructions and also make arrangements for you to come in and have it re-cemented.