What Are Crowns?
A crown is a restoration that covers, or "caps," a tooth to restore it to its normal shape and size, strengthening and improving the appearance of a tooth. Crowns are necessary when a tooth is generally broken down and fillings won't solve the problem. If a tooth is cracked, a crown holds the tooth together to seal the cracks so the damage doesn't get worse. Crowns are also used to support a large filling when there isn't enough of the tooth remaining, attach a bridge, protect weak teeth from fracturing, restore fractured teeth, or cover badly shaped or discolored teeth. Crowns are often used on teeth that have had root canal fillings because the teeth are brittle and can fracture more easily. Often a crown on a root canal filled tooth will also need a post placed part way down into the root canal to gain more strength and support under a crown.
How is a crown placed?
To prepare the tooth for a crown, it is reduced so the crown can fit over it. An impression of teeth and gums is made and sent to the lab for the crown fabrication. A temporary crown is fitted over the tooth until the permanent crown is made. On the next visit, we remove the temporary crown and cement the permanent crown onto the tooth.
Will it look natural?
Yes, unless you wish to have a gold or metal colored crown. Our main goal is to create crowns that look like natural teeth. That is why we take an impression. To achieve a certain look, a number of factors are considered, such as the color, bite, shape, and length of your natural teeth. Any one of these factors alone can affect your appearance.
If you have a certain cosmetic look in mind for your crown, discuss it with us at your initial visit. When the procedure is complete, your teeth will not only be stronger, but they will be more attractive.
Why crowns and not veneers?
Crowns require more tooth structure removal; hence, they cover more of the tooth than veneers. Crowns are stationary and are customarily indicated for teeth that have sustained significant loss of structure, or to replace missing teeth. Crowns may be placed on natural teeth or dental implants.
What is the difference between a cap and a crown?
There is no difference between a cap and a crown. A crown is the more proper name.
Crowns can be made of a variety of different materials and new materials are continually being introduced. Some of the most popular options are listed below.
Porcelain bonded to precious metal: this is what most crowns are made from. A precious metal base is made and then porcelain is applied in layers over it.
Porcelain crowns: these crowns are made entirely out of porcelain and are not as strong as bonded crowns, but they can look very natural and are most often used for front teeth.
All-ceramic crowns: this modern technique offers a metal-free alternative, which can give the strength of a bonded crown and the appearance of a porcelain crown. Therefore it is suitable for use in all areas of the mouth. Often ceramic crown cores are covered with porcelain for the beauty and strength combination most cosmetic dentists are looking for.
Porcelain and composite: porcelain and composite resin materials can sometimes look the most natural. However, these crowns are not as strong as bonded metal crowns. There are now composite and porcelain mixtures that are very beautiful and much stronger than porcelain or composites alone.
All metal base metal crowns are silver or gold looking non-precious crowns. They are not esthetic and some people are allergic to some of the metals in these crowns. They are the least expensive and least used crowns. Porcelain can be placed over this metal and a good esthetic result can, at times, be accomplished with them.
All metal gold alloy crowns: gold is one of the oldest filling materials. Today it is used with other metal alloys to increase its strength, which makes it a very hardwearing restoration. These crowns are white or gold in color.
How long do crowns last?
According to the Academy of General Dentistry, crowns should last approximately 5-8 years. However, with good oral hygiene and supervision most crowns will last for a much longer period of time. Some damaging habits like grinding your teeth, chewing ice, or fingernail biting may cause this period of time to decrease significantly.
How should I take care of my crowns?
To prevent damaging or fracturing the crowns, avoid chewing hard foods, ice or other hard objects. You also want to avoid teeth grinding. Besides visiting your dentist and brushing twice a day, cleaning between your teeth is vital with crowns. Floss or interdental cleaners (specially shaped brushes) are important tools to remove plaque from the crown area where the gum meets the tooth. Plaque in that area can cause dental decay and gum disease.
What is a Bridge?
A missing tooth or teeth can create an unhealthy situation over time. It is very important to restore these gaps. When one or more teeth are lost or missing, the neighboring teeth can shift, tip or even "super-erupt" into the space. Teeth that have drifted from their normal and healthy position are often more susceptible to decay and gum disease. Further, this movement can lead to changes in a patient's bite that can ultimately put stress on the jaws, muscles, teeth and temporomandibular joints (TMJ). Over time this can affect a patient's ability to chew and may even change the facial appearance depending on the location and number of missing teeth.
Is a Bridge permanent?
The word “permanent” must be defined as fixed or solid rather than removable. If you mean by the word “permanent” that it will last for a life time, then you must know that can never be claimed for any dental treatment. There are two ways to replace a missing tooth or teeth: fixed and removable. A bridge is a permanent or fixed replacement, while a denture is a removable replacement. A bridge consists of replacement teeth (one or more) that are attached to crowns on the adjacent teeth. The porcelain fused to metal substructure bridge replacement teeth are shaped and contoured to blend in with the natural teeth in the mouth. For example, a three unit bridge would be a bridge with one missing tooth that is replaced by a bridge that has two crowns over two teeth at either side of the gap and then one false tooth in the middle that replaced the missing tooth and is attached to the two crowned teeth. This three unit solid porcelain piece is cemented over the two teeth and looks like three teeth in a row. These bridges can be very beautiful.
How long does this procedure take?
This procedure takes two or more visits to complete. At the first visit, the adjacent teeth are reduced; an impression is taken and sent to a dental laboratory for fabrication. At the second visit, the bridge is fit and placed permanently in the mouth. Like crowns, bridges can be made from variety of materials for strength and esthetic appearance.
While it should always be discussed with your dentist before treatment, a fixed restoration is generally considered to be the favored solution for tooth replacement over a removable partial denture. But today the implant replacement of missing teeth is considered a better solution than a fixed bridge and is considered the best solution of all. If for example, the teeth on either side of the missing tooth have never been filled and are essentially flawless, implants are often the best solution, because we do not have to cut these flawless teeth. If on the other hand the teeth on either side of the missing tooth are badly broken down and need crowns anyway, then a fixed bridge is a good solution too. One must remember that implants tend to keep bone in the missing tooth area from resorbing away while a fixed bridge does not, and over time the bone in the missing tooth area under a fixed bridge will resorb such that a gap will form under the false tooth part of the bridge and begin to show between the tooth and gum.