There is no difference between a cap and a crown in dental work, according to Know Your Teeth. A crown covers a tooth in order to restore the tooth's normal shape and size, both to improve the appearance of the tooth and to strengthen the tooth.
Crowns are used to repair broken or damaged teeth without the need to remove the tooth, according to Wayne Family Dentistry. A bridge is distinct from a crown or a cap because it uses existing teeth to fill in an area that is missing a tooth. The bridge anchors the new, prosthetic tooth to two adjacent teeth.