Dental Crowns are dental restorations that surround the prepared tooth structure to help strengthen weakened teeth that have been cracked, broken or decayed. It can also be used to help restore a tooth’s shape and improve chewing function, speech and aesthetics. These crowns are made from various types of materials which get bonded or cemented into place. Crowns can be made from all porcelain (or some form of dental ceramic), metal (a gold or other high noble metal alloy), or a combination of both.
A crown is made in a dental laboratory from the impression or scan that your dentist took of your prepared tooth. Your dentist prepares your tooth by first removing any old, failing restorations, and any weak or decayed areas of tooth structure. The core of the tooth is then built up with resin-type materials that simulate the tooth structure it is replacing. Enough tooth structure is removed all around to allow for the proper thickness of metal and/or porcelain which gets fabricated by the dental lab. An impression of the crown preparation is taken using an impression material and this is sent to the lab for crown fabrication. A temporary crown is then made to protect the core and preparation and cemented on with temporary cement. On average it takes about 2 weeks for this restoration to be ready for insertion.
Frequently Asked Questions (FAQ)
Q. When would someone choose to make an all-porcelain crown instead of choosing a traditional porcelain fused to metal crown?
A. Porcelain or all ceramic crowns are chosen when aesthetics is of paramount importance. These materials can have different shades of porcelain layered together to create a very polychromatic, natural looking tooth with natural translucencies and characteristics that blend better with the teeth surrounding them. Once metal is involved, the dental lab technician would have to place a white opaque material over the metal to try and block out the dark characteristics. As a result light doesn’t get reflected; instead gets absorbed, resulting in a more monochromatic, less natural looking tooth. You can still have good aesthetics with porcelain-fused-to-metal crowns, but it may require more tooth preparation to allow for more room for the layering of the porcelain to mask what is underneath. When the patient is a grinder, or requires more strength and stability, the dentist may recommend a crown that is reinforced with metal, although there are new materials now that are very strong that do not contain any metals (such as Zirconia and Procera crowns).
Q. Why do you need a dental crown?
1. To protect the breaking of the cracked or weak tooth.
2. To conceal a severely discoloured tooth.
3. To cover a dental implant.
4. To make a tooth strong after a root canal.
5. To keep a dental bridge in place.
6. To touch up severely worn and broken tooth.
7. To fix misshaped teeth.
8. To cover a tooth with a huge filling.
Q. How long does a dental crown last?
A. A dental crown can last approximately 15-30 years depending on your oral hygiene, regular dental visits and habits – biting of fingernails and hard candies, chewing of ice, teeth grinding, etc.
Q. How many visits are needed for a Dental Crown treatment?
A. Two visits are usually required. The first appointment involves preparation of the crown and impression taking and provisionalisation. The second appointment involves cementing on the permanent crown.