Can you cover a tooth with exposed nerve?

If you need a root canal it is best to have the root canal done first, then place a crown or porcelain onlay on the tooth!If there is not enough support for the tooth porcelain crown will be placed and of course you will have a temporary crown on your tooth, prior to receiving the final crown from your dentist.

Hi:Normally, if the tooth is not treated there will be infection.  It’s best to get the root canal done right away then cover the tooth with a crown.Best,Dr. Maddahi

How long you're thinking about postponing the root canal. you really shouldn't because sometimes it can make it worse. if it's a visible tooth you can have a temp crown but again don't postpone it for too long. it will cause an abscess & swelling.