What Are Dental Crowns and Bridges?
Both dental crowns and bridges are fixed prosthetic appliances, and they are cemented onto the existing natural tooth structure, or onto an implant. They cannot be removed and are designed to look as similar as possible to natural teeth.
Having a Crown Fitted
Your dentist is likely to have recommended you have a crown fitted if you have suffered decay or damage to a tooth. This will have resulted in loss of natural tooth structure, and a crown is an excellent way of protecting and preserving the remaining tooth. Crowns can also be used to cover up a tooth which is misshapen or discolored, or which has had root canal treatment.
Having a Bridge Fitted
If your dentist has recommended you have a bridge fitted, then this will be to replace one or more missing teeth in your mouth, and it literally bridges the gap. It’s fitted onto the teeth either side of the gap left by the missing tooth, and does mean that some healthy tooth structure will need to be removed from these adjacent teeth. This is to ensure there is sufficient room for the bridge to be constructed, as it has to be a minimum thickness in order for it to be strong enough to withstand the forces exerted by chewing.
What Are Crowns and Bridges Made From?
Crowns and bridges can be made from quite a wide variety of materials, and the choice can depend on the position of the restoration and your wallet. Crowns and bridges can be made out of gold or metal alloys, and these can either be polished or can be covered with ceramic or acrylic materials. They can also be completely metal free.
Gold Crowns and Bridges
Your dentist may recommend having an all gold crown or bridge if it’s to be placed in an area where your bite is very heavy, and where space is too limited to use metal bonded to porcelain restorations. The reason for this is that porcelain isn’t always strong enough to withstand the biting forces exerted by the back teeth.
The advantage of having a gold crown or bridge is that it’s very long-lasting and hard wearing. The disadvantage is that having metal visible in the mouth can create dark areas.
Porcelain Bonded to Metal Crowns and Bridges
Crowns and bridges are frequently constructed using a metal base that is covered in porcelain, and this produces good aesthetic results as the porcelain is matched to the patient’s natural tooth colour. Sometimes a crown or bridge may be constructed to show small amounts of metal on the chewing surfaces, as the biting forces exerted during chewing could chip and crack the porcelain.
It’s very unlikely that the metals used in these types of restorations will cause any sensitivity, but some people can have an allergic reaction to the alloys.
All-Ceramic Crowns and Bridges
All-ceramic crowns and bridges use the latest technology to produce metal free restorations, and some of these can be extremely strong. If you have an all-ceramic bridge then it’s likely the base will be made out of material called zirconia, and this is a high-tech material that has been used in space shuttles as well as in the disc brakes of expensive sports cars. As well as being very strong and light, zirconia is relatively inert and won’t react with any of the tissues in the mouth.
Restorations using this material can look incredibly natural and aesthetically pleasing. The reason for this is that the light is able to pass right through the structure in a similar way to a natural tooth. These types of restorations can be used to replace a single tooth, but are also suitable for large bridges. Another type of all-ceramic restoration uses a ceramic pressed under vacuum to create a strong crown, and again this produces very natural results, but is more suitable for front teeth or teeth that aren’t subjected to strong biting forces.
Will These Restorations Last Forever?
The short answer is no, as you will need to budget to have them replaced eventually. The longevity of a restoration does partially depend on your oral health, and how well you look after your crowns and bridges. They should last anything between five and fifteen years, but can sometimes last a lot longer. It’s also important to choose a great dentist who will ensure your restoration fits properly around all the margins of the tooth. This will help prevent any further decay and infection, and will improve the longevity of both the tooth and the restoration.