Crowns- a tooth will sometimes need more protection than a filling can provide.  A crown on a tooth acts as a helmet on your head.  It protects the tooth from biting forces that can crack the tooth and result in tooth loss.  Crowns can be made of tooth colored materials, metal, or a combination of both.  There is no best crown.  The strongest is not the most esthetic.  A crown must restore the tooth to proper shape and function that will allow the patient proper maintenance for health.

This is a 3/4 gold crown that is over 10 years old and still looks like it did the day it was put in.  

These are porcelain fused to metal crowns that Dr. Nogueiro placed over 20 years ago.

This is an example of a zirconium oxide crown. There is no metal substructure. 

This is an example of LAVA crowns. They contain no metal and offer the best aesthetics.