Crowns are dental restorations that cover damaged or weakened teeth. They are necessary when a tooth has decayed, cracked, or been damaged and a filling would not be sufficient to repair it. Crowns can be made from porcelain, porcelain fused to metal, or gold. The process of getting a crown involves reshaping the tooth, taking a mold, making the crown off-site, and cementing it into place over two or three visits to provide strength and restore a natural appearance to the tooth. Crowns are durable and can last 10-15 years with proper oral hygiene.