What is a Crown?
A crown is a type of dental restoration which completely caps or encircles a tooth or dental implant.
When is a Dental Crown Needed?
A dental crown may be needed in the following situations:
- To protect a weak tooth (for instance, from decay) from breaking or to hold together parts of a cracked tooth.
- To restore an already broken tooth or a tooth that has been severely worn down.
- To cover and support a tooth with a large filling when there isn't a lot of tooth left.
- To hold a dental bridge in place.
- To cover misshapen or severely discolored teeth.
- To cover a dental implant .
- To make a cosmetic modification.
- Protect the teeth of a child at high risk for tooth decay, especially when a child has difficulty keeping up with daily oral hygiene.
- Decrease the frequency of sedation and general anesthesia for children unable because of age, behavior, or medical history to fully cooperate with the requirements of proper dental care
For children, a crown may be used on primary (baby) teeth in order to:
- Save a tooth that has been so damaged by decay that it can't support a filling.
How long do dental crowns last?
On average, dental crowns last between five and 15 years. The life span of a crown depends on the amount of "wear and tear" the crown is exposed to, how well you follow good oral hygiene practices, and your personal mouth-related habits (you should avoid such habits as grinding or clenching your teeth, chewing ice, biting fingernails, and using your teeth to open packaging).
While a crowned tooth does not require any special care, remember that simply because a tooth is crowned does not mean the underlying tooth is protected from decay or gum disease. Therefore, continue to follow good oral hygiene practices, including brushing your teeth at least twice a day and flossing once a day -- especially around the crown area where the gum meets the tooth. Antibacterial mouth rinse can also help.
What Kind of Crowns are Available?
Permanent crowns can be made from stainless steel, all metal (such as gold or another alloy), porcelain-fused-to-metal, all resin, or all ceramic. At Mina Levi, DDS, we specialize in non-metal dentistry, so your crown will most likely be made from ceramic.
- All-ceramic or all-porcelain dental crowns provide better natural color match than any other crown type and may be more suitable for people with metal allergies. However, they are not as strong as porcelain-fused-to-metal crowns and they wear down opposing teeth a little more than metal or resin crowns. All-ceramic crowns are a good choice for front teeth.
What are "onlays" and "3/4 Crowns"?
Onlays and 3/4 crowns are variations on the technique of dental crowns. The difference between these crowns and the crowns discussed previously is their coverage of the underlying tooth. The "traditional" crown covers the entire tooth; onlays and 3/4 crowns cover the underlying tooth to a lesser extent.
With preparing the tooth for a full crown, most of the enamel and dental structure (about 70%) is lost, which makes the 3/4 crown a better option in terms of saving as much natural tooth structure as possible.
What Problems Could Develop With a Dental Crown?
- Discomfort or sensitivity. Your newly crowned tooth may be sensitive immediately after the procedure as the anesthesia begins to wear off. If the tooth that has been crowned still has a nerve in it, you may experience some heat and cold sensitivity. Dr. Mina Levi may recommend that you brush teeth with toothpaste designed for sensitive teeth. Pain or sensitivity that occurs when you bite down usually means that the crown is too high on the tooth. If this is the case, call Dr. Mina Levi. She can easily fix the problem.
Chipped crown. Crowns made of all porcelain can sometimes chip. If the chip is small, a composite resin can be used to repair the chip with the crown remaining in your mouth. If the chipping is extensive, the crown may need to be replaced.
Loose crown. Sometimes the cement washes out from under the crown. Not only does this allow the crown to become loose, it allows bacteria to leak in and cause decay to the tooth that remains. If a crown feels loose, contact Dr. Mina Levi.
Crown falls off. Sometimes crowns fall off. Usually this is due to an improper fit, a lack of cement, or a very small amount of tooth structure remaining that the crown can hold on to. If this happens, clean the crown and the front of the tooth. You can replace the crown temporarily using dental adhesive or temporary tooth cement that is sold in stores for this purpose. Contact Dr. Mina Levi immediately. He or she will give you specific instructions on how to care for the tooth and crown for the day or so until you can be seen for an evaluation. Your dentist may be able to re-cement the crown in place; if not, a new crown will need to be made.
Allergic Reaction. Because the metals used to make crowns are usually a mixture of metals, an allergic reaction to the metals or porcelain used in crowns can occur, but this is extremely rare. At Dr. Mina Levi's office, we do not use metal for crowns so the risk of allergy is removed.
Dark line on crowned tooth next to the gum line. A dark line next to the gum line of your crowned tooth is normal, particularly if you have a porcelain-fused-to-metal crown. This dark line is simply the metal of the crown showing through.