Crowns cover a single tooth that has lost most of its surface due to extensive decay, breakage or root canal therapy or simply fracture of a large dental restoration. Teeth become brittle and break easily after root canal therapy. A crown is also often used to improve the esthetics of a discolored and/or fractured tooth.
A bridge can replace a single or multiple tooth that have been lost. A bridge is simply two or more crowned teeth, which are connected together and look and function like single, natural teeth.