Everything you need to know about dental crowns

Learn all you need to know about dental crowns including the types, installation method and if it is right for you. If you want to speak with a dentist regarding dental crowns in Kingston Ontario to learn more about if a crown is right for you, contact McCabe Family Dentistry for a free consultation. 

What is a Dental Crown?

A dental crown (or cap), is an artificial cover that is placed over your tooth structure, usually in order to protect it from damage.

What are the types of Dental Crowns?

According to the amount of tooth structure covered, there are two types of dental crowns:

Complete coverage crowns:

  • which cover the tooth structure from all the sides, and offers more protection in case the tooth is fragile.

Partial coverage crowns:

  • These cover only a part of the tooth, either ½, ¾ and even 7/8 of the tooth. These of course are less destructive to the natural teeth, however, the most recent guidelines and research proved the partial coverage crowns to be ineffective and most modern dentists will go for the full coverage in all cases.

There are 4 types of materials used for the creation of a dental crown:

Metal crowns:

where the entire surface of the crown is made from metal. These are more suitable for the back teeth as they look really ugly, and they are almost not used anymore nowadays. In the old days, these used to be made of gold, but now most metal crowns are made of a cobalt-chromium alloy.

Metal ceramic crowns:

these have a core built from metal, and covered by a layer of porcelain that has a similar look as that of natural teeth. The porcelain can cover the entire metal core, or only the visible outer part of the crown.

All-ceramic crowns:

These have no metal at all. The entire crown, core and covering, is made from a ceramic material. Two main materials are used to build the core, either zirconium (otherwise known as fake diamonds), or porcelain itself. The core is then covered by another layer of porcelain to mimic the shade of the natural tooth. This type is under a lot of demand nowadays, with the development of cosmetic dentistry, though it is not recommended for everyone.

Stainless Steel Crowns:

These are ready made crowns, that are only placed over the teeth after they receive a root canal treatment, and is mainly used with immature teeth of children to protect them until they are ready to withstand the forces of biting and chewing.

How do I know which type is suitable for me?

The type of dental crown chosen is selected by the dentist usually according to the location, where metal or metal with porcelain crowns are stronger, but the metal will eventually show and the appearance is compromised, so they are more commonly used on posterior teeth. On the other hand, all porcelain crowns are much better looking since they have no metal, but lack the strength of metal, so they are placed on the front teeth as strength is not needed as much as looks. A lot of research in the dentistry field is directed towards how to make all ceramic restorations stronger and more durable, so that in the near future, metal crowns will no longer be needed.

Who Should receive a Dental Crown?

Dental crowns are made for patients whose teeth are in danger if fracture or breaking. The most common type of these patients are patients who underwent root canal treatment, leaving the teeth vulnerable and more liable to fracture. Another example is a tooth severely damaged by decay, where a normal filling will not be sufficient to endure the biting forces and a dental crown is the only way to keep the tooth functioning for as long as possible. Another candidate to receive a dental crown is a patient who cracked or fractured his or her teeth, due to biting accidentally on a hard object, and other habits such as teeth grinding and nail biting that causes a part of the tooth to be chipped clean off. If that part is small enough, it can be replaced by a filling; however, if the fractured part is large, a crown will most certainly be needed.

How is the crown made and how is it attached to the tooth?

First the dentist must make sure that your teeth and your mouth are suitable to receive a dental crown. Oral hygiene must be supreme, and the tooth (or teeth) that will be covered by the crown should be free from decay and gum disease, and the bone surrounding it should possess enough strength to support the crown.

When the tooth and mouth are ready, the dentist will start the preparation part, by removing 1-2mm all around the tooth, so that the crown that will be made is not too large, and its looks and function are identical to the original tooth. Your dentist will then take a replica (Called an impression) of your teeth and send it to the laboratory. The laboratory will use a special technique to fabricate the crown and return it back to the dentist.

Recently, with the development of computer and imaging technology, emerged a concept known as CAD / CAM technology (which stands for computer aided design / computer aided manufacturing). This technology allows the dentist to use a specially made camera to scan the tooth surface after preparation. This camera will then send this scan to a special computer, which designs the dental crown’s shape and structure. This computer is also linked to a milling machine, which reads the design made by the computer and starts to mill the dental crown out of a block of metal or porcelain according to the type, and the patient can receive his\her crown within an hour. Needless to say that this technology is a revolution in the dentistry field, and may in fact eliminate the need for laboratories.

After the crown is fabricated and returned to the dentist, The dentist will make some small adjustments and then use a special type of glue (called the dental cement) to fix it on the tooth.

The types of cements vary according to use and according to the material as follows:

  • Temporary cement: Which is designed to hold the crown for a small period of time. The crown will then be removed for adjustments , and re-cemented with permanent cement .These are usually made of a material called Zinc Oxide mixed with Eugenol (or Clove) oil , which is why they smell so familiar to you .
  • Permanent cement: Which, as the name implies, is designed to hold the crown in its position forever. If the crown is cemented with this type of cement, it shouldn’t be removed. These are made from a material called glass ionomer, or the stronger type which is called the resin cement.

If you wish to speak with a dentist in Kingston, Ontario, contact us for a free consultation.

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