Generally speaking, crowns are a cosmetic restoration used to strengthen a tooth or improve its shape. Crowns are most often used for teeth that are broken, worn, or partially destroyed by tooth decay.
Crowns are "cemented" onto an existing tooth and fully cover the portion of your tooth above the gum line. In effect, the crown becomes your tooth's new outer surface. Crowns are usually made of porcelain, metal, or both. Porcelain crowns are most often preferred because they mimic the translucency of natural teeth and are very strong.
Why and when?
Dr. Darlene Jeffries, an experienced dentist from Pittsburgh-based dental practice Jeffries, Smith & Associates (JeffriesSmithAndAssociates.com) explains: “Crowns or onlays (partial crowns) are needed when there is insufficient tooth strength remaining to hold a filling. Unlike fillings which apply the restorative material directly into your mouth, a crown is fabricated away from your mouth. Your crown is created in a lab from your unique tooth impression which allows a dental laboratory technician to examine all aspects of your bite and jaw movements. Your crown is then sculpted just for you so that your bite and jaw movements function normally once the crown is placed.”
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 take 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.
Excessive wear of teeth: If a person has a habit of grinding their teeth, the teeth will become shorter over time. The teeth can also wear away due to acid erosion caused by gastrointestinal acid reflux, bulimia, or an acidic diet. Sometimes, the enamel will wear away completely, leaving small, soft teeth. Over time, the bite can collapse and the only way of restoring the teeth to normal size is by covering the teeth with crowns.
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 they don't even require preparing or shaving the existing teeth.
Other: Crowns are placed on dental 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.
What types of dental crowns are available?
Crowns can be made out of a gold alloy, some other metal alloy, stainless steel, all-porcelain/all-ceramic, composite resin, zirconia, or porcelain on the outside fused to metal or zirconia on the inside. In some cases, ceramic crowns can be made with CAD/CAM technology by milling the crowns out of blocks of porcelain in the dental office, without the need for temporaries or a dental laboratory. There are advantages and disadvantages to all of the types of dental crowns. Stainless steel crowns are preformed crowns used to cover baby teeth for children. Gold dental crowns have traditionally been the most durable and require less of the tooth to be removed or shaved down. The primary advantage of porcelain crowns is their esthetics, while newer types of ceramic crowns have become increasingly more durable.
Find a dentist with extensive dental crown experience
Finally, knowing that your teeth have been damaged or incomplete may have been holding you back more than you realized. If you're trying not to smile with your lips open, seeming subdued at work, or are always self-conscious in personal or professional situations, you could easily be missing opportunities to shine and dazzle those around you.
Even if you've missed some in the past, take an opportunity to look into dental crowns which can improve your experience with your teeth for the rest of your life. A consultation with experienced dentists that have installed hundreds of crowns, like Drs. Darlene and Dr.Zena Jeffries can determine if a crown is the best solution for your dental situation.