A crown is restoration that covers the entire portion of a single tooth. It usually covers the sides as well and goes all the way down to the gumline. Typically, crowns are made out of porcelain, but other materials can also be used to fabricate dental crowns. The procedure works like this: you usually need to have local anesthetic in the area to be worked on. Your dentist will reduce the tooth as needed to allow for the proper amount of space for the restorations. Impressions will be taken and sent to the lab. While the lab is making your tooth (this usually takes about 2 weeks), your dentist will make you a temporary crown to hold the place. You will have to come back for a second appointment. At your second appointment, your temporary crown will be removed, and the permanent one will be cemented in. Hope that helps!