A dental crown is basically a covering or a cap for a tooth that has been damaged. It is made using a variety of materials, which can include porcelain or metal. The crown not only helps a tooth improve its appearance but also helps to restore its shape, strength and size.
After being cemented into place, a crown will be fully encasing the entire visible portion of a tooth that lies at and above the gum line. Before undergoing the procedure, you should discuss with your dentist your various options, so that he/she can figure out what meets your needs the best.
A dental crown is needed in various situations:
- To prevent a weak or decayed tooth from breaking or to hold together parts of a cracked tooth
- To cover and support a tooth with a large filling when there isn’t much of the tooth left
- To restore a tooth that is already broken down or a tooth that has been worn down severely
- Covering teeth that are misshapen or severely discolored
- Holding a dental bridge in place
- To make a cosmetic modification
- To cover a dental implant
A crown may be needed for children on their primary teeth for the following reasons:
- Saving a tooth that has been too damaged by decay and is unable to support a filling
- Protect the teeth of a child who is at high risk for tooth decay. This is especially required when a child has difficulty keeping up with his/her daily oral hygiene.
In such cases, generally, a stainless steel crown is recommended by a pediatric dentist.
Permanent crowns are made from stainless steel, ceramic or metals like gold and other alloys.
Stainless steel crowns are prefabricated crowns to be used on permanent teeth primarily as a temporary measure. This crown helps to protect the tooth or filling while a permanent crown is being prepared from another material.
Metals which are used in crowns usually include alloys having a high content of gold or platinum or base-metal alloys (such as cobalt-chromium and nickel-chromium alloys). Metal crowns are able to withstand biting and chewing forces well and therefore, they usually last the longest in terms of wear-down. Metal crowns are known to chip or break quite rarely, which is another advantage. However, one drawback is the metallic color and the high price of gold. Metal crowns can, however, be a good choice for out-of-sight molars.
Porcelain-fused-to-metal dental crowns can be matched to the color of your adjacent teeth, unlike the metallic crowns. However, you should also note that they usually cause more wearing to the opposing teeth, as compared with metal or resin crowns. The crown’s porcelain portion may sometimes chip or break off. Porcelain-fused-to-metal crowns usually look like normal teeth. However, in some cases, the metal which is underlying the crown’s porcelain can show through as a dark line, especially at the gum line and even more, if the gums recede. These crowns are a better choice for front or back teeth as well as long bridges where the metal is required for strength.
All-resin dental crowns can be less expensive than other crown types, but the disadvantage is that they wear down over time. As compared to porcelain-fused-to-metal crowns, they are also more prone to fractures.
All-ceramic or all-porcelain dental crowns are known for providing better natural color match than any other crown type. They are generally more suitable for people who are allergic to metal.
Preparation and Procedure
Usually, two visits to your dentist are required when you prepare your tooth for a crown.
At your first visit in preparation for your crown, your dentist might take few X-rays for checking the roots of your tooth which will be receiving the crown and its surrounding bone. If your tooth is going through extensive decay or if there is any risk of infection or injury to the pulp of the tooth, then first a root canal treatment might need to be performed.
Before the crown-making process begins, your tooth and its surrounding gum tissue will need to be numbed. After this, your tooth is reshaped along the chewing surface and sides to help make room for the crown. The amount that is removed will depend on the type of crown used. However, if a large area of the tooth is missing from your tooth, due to decay or damage, your dentist will be using filling material for building up the tooth for supporting the crown.
After your tooth is reshaped, your dentist can use a paste or putty for making an impression of the tooth to receive the crown. Impressions can be made with a digital scanner. They will be sent to a dental lab, for the crown to be manufactured. Within three weeks, the crown will be returned to your dentist’s office. If your crown is made from porcelain, then your dentist will also need to select the shade that matches the color of the neighboring teeth.
In your first visit, your dentist will make you a temporary crown for covering and preparing the prepared tooth, while the permanent crown is being prepared.
At your second visit, the dentist will first remove the temporary crown. Then he/she will check the fit and color of the permanent crown. If everything is acceptable, they will be using a local anesthetic to numb the tooth after which they will be placing the permanent crown.
Once the crown has been fit, it is very important to take proper care of it, to help prolong its life.
Practice brushing your teeth carefully. It is best if you brush your teeth at least twice a day. You can consider using toothpaste which is meant for sensitive teeth.
Avoid hard foods. Chewing hard foods or ice can lead to your crown cracking, especially if it is made of porcelain.
Risks and Complications
Though a crown can be a very useful solution to significant tooth problems, there are few risks and possible complications that you might experience after the procedure:
Teeth sensitivity- It’s not uncommon for a crowned tooth to become sensitive to heat or cold.
However, if you find your tooth very sensitive to pressure when you bite down, the fit may be off. You should talk with your dentist about changing the placement of the crown or the filling down the top of your crown.
Chipped crown- Certain types of crowns, notably all-porcelain crowns, can be more vulnerable to chipping. However, small chips can be easily fixed by your dentist.
The porcelain used for porcelain-fused-to-metal crowns can break away sometimes. This can reveal the metal structure underneath. If the metal is still intact, these chips may not need to be repaired.
Gum disease- If you see the gums around your crown getting sore or irritated, or if you see this area bleeding, it could be that you are developing gingivitis or gum disease.
Crown knocked out or loose- Your crown can sometimes get loose or fall out if there’s not enough cement to keep it in place. You should consider calling your dentist if you feel your crown loose or wiggly.
Allergic reaction- Although quite uncommon, few people can sometimes have an allergic reaction to the metal which is used in some crowns.