Crowns & Bridges
What are Dental Crowns?
A dental crown is a restoration that covers or caps a tooth, restoring it to its normal size and shape while strengthening and improving its appearance. Crowns are necessary when the tooth is broken down to the point where a filling will not be effective.
Types of Dental Crowns
There are several different methods of crown restoration, each using a different crown material. Different types of crown material include:
Metal crowns are made entirely of a metal alloy that may include gold, platinum, palladium, or other elements. Compared with other kinds of crowns, metal crowns preserve more of the tooth structure. They withstand biting and chewing forces well and rarely chip or break. The biggest drawback of metal crowns is the metallic color.
Porcelain-Fused-to-Metal or PFM Crowns
PFM crowns can be color-matched to the teeth. Second only to all-ceramic crowns in appearance, porcelain-fused-to-metal crowns look like normal teeth. In some cases, the metal underlying the crown's porcelain can create a dark line. PFM crowns tend to wear down opposing teeth more than metal crowns. The crown's porcelain portion can also chip or break.
All resin crowns are the least expensive type of dental crown. The drawback is that they are more prone to chips and fractures than other crowns and tend to wear down over time.
Ceramic or Porcelain Crowns
These crowns provide the best natural color of all the dental crowns. They are not as strong as PFM or gold crowns, and they may wear down opposing teeth more than metal or resin crowns. Because they are the most cosmetically pleasing, they are commonly used for the front teeth.
Complications of Dental Crowns
Some patients experience increased sensitivity immediately after the procedure, particularly if the crowned tooth still has a nerve in it. For sensitivity to heat and cold, some patients are advised to use toothpaste for sensitive teeth. Other complications that may occur with dental crowns are:
- Pain or Sensitivity When Biting - This usually means that the crown is too high on the tooth. If this is the case, the dentist will be able to fix the problem by adjusting the crown.
- Chip in a Porcelain Crown - Resin can be used to repair the remaining crown. If the chipping is extensive, the entire crown may need to be replaced.
- Loose Dental Crown - If the cement washes out from underneath the crown, bacteria can then leak in and cause decay. A dentist should be consulted to resecure the crown to alleviate the problem.
In some cases, a dental crown may fall off entirely. If this happens, contact the dentist immediately. The dentist may be able to replace the crown or create a new crown if necessary.
With proper oral hygiene, dental crowns can last from five to fifteen years. Patients should consult with their dentist to see if dental crowns are appropriate for their individual condition.
What are Dental Bridges?
As the name implies, a dental bridge spans the gap created by a missing tooth or teeth. Like a bridge you drive across, a dental bridge has three parts: two crowns (called the abutment teeth) on each side of the gap and the span in the middle. In this case the span is an artificial tooth or teeth (called the pontics). Bridges are made as a single piece and are permanently cemented onto the two abutment teeth.
This is a description of a traditional bridge, but “cantilever bridges” are used when there are healthy teeth for anchoring on only one side of the missing tooth or teeth. “Maryland bridges” are used on the front teeth.
Dental bridges are natural-looking tooth replacements that help maintain facial structure, reduce stress on the jaw and fill in the gaps caused by missing teeth.
What are Dental Bridges Used to Treat?
A dental bridge can be used to:
- Restore an attractive smile
- Reduce the risk of gum disease
- Restore the ability to bite and chew
- Improve speech
- Prevent remaining teeth from drifting out of position
Types of Dental Bridges
There are three main types of bridges:
Also known as fixed bridges, traditional bridges are used to replace one or more missing teeth. The procedure involves creating a crown for the tooth or implant on either side of the missing tooth, with a pontic, or a false tooth, in between. Fixed bridges are the most common type of dental bridges and are either made out of porcelain fused to metal or out of ceramics.
Also known as Maryland-bonded bridges, resin-bonded bridges are primarily used for the front teeth. They are less expensive than fixed bridges and are best for use when the teeth are healthy and do not have any large fillings. During this procedure, a false tooth is fused with resin to metal bands which are then bonded to the adjacent teeth and hidden from view. Resin-bonded bridges require only minimal preparation of the adjacent teeth.
These bridges are used in areas of the mouth that are under minimal stress, such as the back teeth. Cantilever bridges are recommended when there are teeth on only one side of the open space.
The Dental Bridge Procedure
There are several steps that are taken in order to create a bridge:
The adjacent teeth must be prepared. This involves removing some of the enamel to allow room for the crown to be placed over them.
Impressions of the teeth are made. These will be sent to a laboratory so a bridge, a false tooth or pontic, and crowns can be created to fit the unique configuration of the patient's mouth. During the 2 to 3 weeks while the bridge is being manufactured, the patient will be given a temporary dental bridge to protect the exposed teeth and gums.
During the next dental visit, the temporary bridge will be removed and replaced with the new, permanent bridge. The doctor will make sure the bridge fits properly and cement it to the teeth.