The anatomy of a tooth can be divided into two basic parts — the root and the crown. The crown is the part of the tooth visible in the mouth, above the gum line on lower teeth and below the gum line on upper teeth. A cemented restoration that partially or completely covers the outside of the tooth is referred to as a dental crown.
The dental crown is a fixed prosthetic device which is used to cap the damaged tooth. It not only protects the tooth but also enhances the appearance, shape, and alignment. These Dental crown, when cemented into place, fully encase the entire visible portion of a tooth that lies at and above the gum line.
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.
Root canal: Root canal treatment leaves the tooth hollowed out and predisposes the remaining tooth to crack. So, a tooth that has had a root canal almost always needs to be restored with a crown immediately to prevent it from fracturing.
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.
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 or an acidic diet. Sometimes, the enamel will wear away completely, leaving small, soft 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