There are a number of situations where a tooth has to be restored with a dental crown or cap. The following are the most common:
Big filling: When a tooth has a cavity that is bigger than half the width of the tooth, it can’t be filled, but needs to be covered with a crown, as the remaining tooth around a large filling is so weak that it is likely to fracture. If a tooth with a large filling that has been in the mouth for a while shows signs of cracks and stress around the filling, it will need to be replaced with a crown.
Root canal: Root canal treatment hollows out the tooth out and the remaining tooth will be susceptible to cracking. In this case, a crown has to be fitted immediately to prevent the tooth from cracking or splintering.
Cracked tooth syndrome: When a person has fractures inside a tooth that cause pain when it is used to chew in a certain way, it is likely caused by cracked tooth syndrome. Chewing causes stress on fracture lines that make it feel like the tooth is splitting apart. A crown will redistribute the stress throughout the tooth evenly and hold the tooth together, eradicating the pain in most cases.
Broken cusps: Due to large existing fillings or trauma, cusps frequently break off teeth. As the cusp is the part of the tooth that experiences the most stress during chewing, it will keep fracturing if it is not completely covered. A tooth can also break all the way to the bone. In this case, a crown lengthening procedure is necessary. The bone and gums are trimmed down to below the edge of the fractured part of the tooth, so the crown can be placed on strong, healthy tooth structure.
Excessive wear of teeth: Teeth will become shorter over time if a person has a habit of grinding their teeth. Teeth can also wear down due to acid erosion caused by bulimia, gastrointestinal acid reflux, or an acidic diet. The enamel will even sometimes wear away completely, leaving small, soft teeth. The only way of restoring teeth like this properly, is by covering them with crowns.
Undesirable appearance of teeth: Teeth that have an unacceptable appearance due to shape, color, or spaces between teeth, can be restored to look very natural with crowns. Dental veneers are a very conservative and effective way to enhance the look of the front teeth. They can make the teeth appear very natural and often don’t even require preparation, or shaving of the existing teeth.
Other: Crowns are placed on dental implants to reinstate spaces left from missing teeth. These spaces can also be filled 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 several teeth and strapped together to provide more strength.