Dental crowns can be used in a number of different situations. They can be used to repair a tooth that has been worn down or is broken and the patient is suffering from a toothache. They can repair and protect a tooth that is cracked or has a large amount of decay. They can also repair a tooth that has had root canal treatment. They can be used to treat minor tooth alignment problems. They can also be used to improve the appearance of a tooth that is discolored, and they are used when you have dental implant treatment.
Dental crowns can be made of a number of different materials. The crowns that give the best appearance are ones made of full ceramic or full porcelain. They are not as strong as some other types of crown and so are not normally used for rear teeth which are subjected to considerable wear from chewing. These crowns are also suitable for patients who may suffer from allergy to some metals.
The most common type of crown used by dentists is what is known as a PFM (Porcelain Fused to Metal) crown. These are recommended for rear teeth because the metal base is very strong and can withstand the pressure that comes from chewing. Different types of metal base may be used, and these include chromium and nickel. In addition, the porcelain can be fused to silver, gold, or platinum and these sorts of crown are naturally more expensive.
PFM crowns have a couple of disadvantages. If they are used for front teeth the metal base can show through as a shadow in full daylight. Second, if the gums recede from the crown over time, the metal base will show through as a dark line at the point where the gum meets the crown.
The most expensive crowns are those made from the metal zirconia. These are immensely strong and can be used for front or back teeth, and they have an excellent appearance which is as good as full ceramic or full porcelain crowns. They can be made from solid zirconia or they can be used as a base for a porcelain veneer. Because zirconia is so strong the crown can be thinner than other types and they won’t need so much of the tooth to be removed as other crowns.
Temporary crowns can also be used and these are usually made from acrylic. These can be fitted while the permanent crown is being crafted in the dental laboratory. In some patients, crowns will last for their whole life, but in most cases the lifespan is from 10 – 15 years, after which they will need to be replaced. Most problems with crowns are the result of gum disease or decay of the supporting tooth, but crowns can also become chipped or cracked.
In order to prepare for a crown, the dentist will take x-rays or a CAT scan to look at the tooth root and check for any cavities that may be causing a toothache. The tooth will then need to be filed down and possibly re-shaped. The dentist may also take an impression of the tooth and will take shade photographs so that the crown can be exactly matched to that of the surrounding teeth. These are then sent to the laboratory technician for the crown to be made. It is important to note that if you are going to have teeth whitening this must be done before the crown is fitted, as the crown itself cannot be whitened.
As for the length of time for crowns to be fitted, it used to be the case that you would need to make several visits to the dentist and spend several hours in the chair. However, today we have computer-aided design which can considerably speed up the process. Increasingly, some dentists today are installing their own laboratories so that in some cases the tooth can be prepared and the crown fitted on the same day.
Dental crowns are also fitted when a dental implant is used. The titanium implant is inserted into the jawbone and the crown fits on top of it. Dental implant treatment is not cheap, but provides a tooth that works in exactly the same way as the original.