A dental crown is a tooth-shaped "cap" that is placed over a tooth -- to cover the tooth to restore its shape and size, strength, and improve its appearance. The crowns, when cemented into place, fully encase the entire visible portion of a tooth that lies at and above the gum line. Your dentist may recommend that you undergo a dental crown procedure for one of several reasons: you have a particularly weak tooth that needs to be held together or has a large portion that broke off; you have a tooth that is extremely discolored; you have a tooth with an existing root canal (making it fragile); or you wish to have a crown placed for cosmetic reasons.
The procedure for a dental crown normally takes two separate visits. At your first appointment, your dentist will examine the tooth to make sure that it can support a crown, then begin shaping it to prepare for the crown. If the tooth is severely damaged or broken, your dentist may need to fill it in to make it large enough to properly receive the crown. Your practitioner will take an impression of the tooth, as well as those surrounding it, and send it away to a dental lab, so the permanent crown can be made. By the end of this first visit, your tooth will have a new temporary crown that protects it until the final crown is ready to be permanently placed.
When the permanent crown is ready, you will have your second visit. At this appointment, the temporary crown is removed, after which the dentist will position and fasten the new crown to the tooth with a special cement.