If you want a smile that’s your crowning glory, you may need a crown to cover a tooth to help restore it to its normal shape and size. A crown can make your tooth stronger and improve its appearance.
A crown can also help strengthen a tooth with a large filling when there isn’t enough tooth remaining to hold the filling. Crowns can also be used to attach bridges, protect a weak tooth from breaking or restore one that’s already broken. A crown is a good way to cover teeth that are discolored or badly shaped. It’s also used to cover a dental implant.
If Dr. Stokes recommends a crown, it is probably to correct one of these conditions. Dr. Stokes’s primary concern, like yours, is helping you keep your teeth healthy and your smile bright.
What is a dental crown?
The anatomy of a tooth can be divided into two basic parts -- the root and the crown. In a person with healthy gums and bone, the root of the tooth is covered by the gums and bone. The part of the tooth that is visible in the mouth, above the gum line on lower teeth and below the gum line on upper teeth, is called the clinical crown. A cemented restoration that partially or completely covers the outside of the clinical crown is referred to as a dental crown, or cap.
Crown preparation: This is the design of the tooth after it has been shaved down to allow room for a crown. The preparation design depends on the material that the crown will be made from, previous fillings, fractures, and root canal therapy performed on the tooth while trying to maintain enough tooth structure for the crown to adhere onto.
Margin: This is the edge of the crown that meets the prepared surface of the tooth. This needs to be smooth with no gaps or ledges.
Cusps: These are the raised or pointy parts of a crown that are the primary tools for tearing and chewing food. When a cusp has been damaged from a cavity or fracture, the tooth needs a crown to prevent further damage.
Partial crown/onlay: This is a crown that only covers some of the cusps of the tooth, but not all of them. This restoration is chosen as a conservative measure to preserve as much tooth structure as possible. When conditions allow, this is the preferred type of crown restoration.
Dental veneer: This is a partial crown that covers only the front of the tooth. These all-ceramic restorations are usually placed on front teeth to change the color or shape of teeth or add symmetry and balance to a smile.
Temporary/provisional: This is a temporary crown that is placed on the tooth while waiting for the final crown to be made by the dental lab. Temporary crowns shouldn't be left on a tooth for very long because they are made of weak materials and cemented with weak cement that doesn't seal the tooth for very long. Occasionally, a temporary crown will purposely be left on for a prolonged period of time by the dentist to make sure it becomes free of pain or other symptoms.
When is a dental crown needed
There are a variety of situations that require a tooth to be restored with a dental crown. The following are the most common:
Large filling: When a tooth has a cavity or fracture that involves half the width of the tooth or more, it needs to be covered with a crown. This is because the remaining tooth around the large filling is so weak that it is prone to fracture. Sometimes a large filling that has been in the mouth for a while will need to be replaced with a crown because the tooth shows signs of stress and cracks around the filling.
Root canal: Root canal treatment leaves the tooth hollowed out and predisposes the remaining tooth to cracking. So, a tooth that has had a root canal almost always needs to be restored with a crown immediately to prevent it from fracturing.
Cracked tooth syndrome: This is a condition whereby a patient has fractures inside a tooth that cause pain when it is chewed on a certain way. Chewing produces stress on fracture lines that make it feel like it is splitting apart. A crown will hold the tooth together and redistribute the stress evenly throughout the tooth, eliminating the pain in most instances. In these situations, it is best to leave a temporary crown on for a while to make sure the pain goes away and the tooth doesn't require a root canal.
Broken cusps: Cusps frequently break off of teeth due to trauma or large existing fillings. Since the cusps are the part of the tooth that takes the most stress during chewing, they need to be completely covered or the tooth or filling will keep fracturing. Sometimes the tooth breaks all the way to the bone, and a crown-lengthening procedure is necessary. This means the bone and gums need to be trimmed down below the edge of the fractured part of the tooth so the margin of the crown can be placed on healthy, strong tooth structure.
Undesirable appearance of teeth: Teeth that have an unacceptable appearance due to color, shape, or spaces between teeth can be made to look very natural and beautiful with crowns. Dental veneers are a very effective and conservative way of enhancing the look of the front teeth. They can be made to look very natural, and sometimes don't even require preparing or shaving the existing teeth.
Other: Crowns are placed on implants to restore spaces left from missing teeth. Another way of filling these spaces is with dental bridges, which are made from crowns on the teeth next to the spaces attached to fake teeth in the middle. If teeth are loose, crowns can be placed on multiple teeth and splinted together to provide more stability.