“A crown is a dental appliance that replaces and covers the entire part of a tooth above the gum line. A crown may be made of gold, porcelain, or a combination of other man-made materials.
Crowns are used to:
—Repair teeth that have broken or decayed so much that they can no longer be treated with a filling.
—Improve the appearance of front permanent teeth (incisors) that are properly spaced but are rotated and look crooked.
Crowns may be applied after a root canal treatment to seal the tooth and prevent it from breaking.” -WebMD