Re: Cavity and root canal
Gold is a weak metal. You can get pure gold crowns and/or gold plated crowns. A porcelain fused to high noble metal crown is the best crown and one that tends to last much longer than gold crowns. Porcelain fused to high noble metal crowns also will match your other teeth. They look like a natural tooth.
You can get cavities on teeth that have had a root canal. If you choose to have a crown placed on the tooth, you will need to maintain a really good oral hygiene routine. Anything artificial in the mouth, such as a crown, is a natural plaque trap.