Dental Crown Problem

I just had a new crown installed on a tooth that had been crowned previously.  There was decay under the old crown was the reason it was replaced.  Now I cannot chew on that crown.  It is very tender.  I believe I already had a root canal on that tooth.
What could be the problem?

[Jerome Bogin, D.D.S.]

The bite maybe off and needs to be adjusted, the old rct may have a residual infection present, are the contacts open between the new crown and the adjacent teeth? All these are possibilities and need to be checked out by your dentist asap if the discomfort persists.

[thunder111]

A related discussion, broken crown and replacement cost was started.