A crown is a type of dental restoration which completely caps or encircles a tooth or dental implant. Crowns are often needed when a large cavity threatens the ongoing health of a tooth. They are typically bonded to the tooth using a dental cement. Crowns can be made from many materials, which are usually fabricated using indirect methods. Crowns are often used to improve the strength or appearance of teeth. While inarguably beneficial to dental health, the procedure and materials can be relatively expensive.
A bridge is a fixed dental restoration used to replace a missing tooth (or several teeth) by joining an artificial tooth permanently to adjacent teeth or dental implants. A bridge is fabricated by reducing the teeth on either side of the missing tooth or teeth by a preparation pattern determined by the location of the teeth and by the material from which the bridge is fabricated. In other words, the abutment teeth—including portions which are otherwise perfectly healthy—are “reduced” in size using a high-speed rotary tool to accommodate the material to be used to restore the size and shape of the original teeth in a correct alignment and contact with the opposing teeth.