Teeth prepared for dental crowns. Close-up of the upper incisor teeth of a 45-year-old female patient, prepared to receive dental crowns. The decayed parts of the original teeth have been removed and the root canals have been filled. Prefabricated posts have been cemented into holes drilled into the prepared remainders of the teeth. These metal posts are used to support ceramic crowns; artificial caps which fit over the posts and are shaped like natural teeth.