A dental crown is a covering that fits over a decayed, damaged, or unattractive tooth and can replace a tooth entirely as part of a dental bridge. A crown covers a tooth completely above the gum line in contrast to a dental veneer, which only covers a tooth's front surface and needs natural tooth structure to support it. If a tooth is missing a significant amount of structure above the gum line, a crown would be the restoration of choice.
Crowns strengthen damaged teeth, allowing them to function again normally. When crafted from today's porcelains (dental ceramics), crowns are indistinguishable from natural teeth and can be designed to improve upon a tooth's original appearance.
There are other materials besides porcelain that can be used to make dental crowns, such as cast gold, porcelain-fused-to-metal crowns, and all-porcelain crowns with zirconia.