Crowns, also known as "caps",
cover and protect damaged teeth. Crowns can be all gold,
all porcelain or a combination of both depending on functional
and esthetic needs.
Usually it's best to switch to a crown when hardly any
tooth structure remains to keep the tooth from breaking.
After a tooth breaks, it is much more difficult to repair.
Switching to a crown when a large filling has worn out protects
and strengthens the tooth.