Replace the temporary crown as soon as possible.

While you are waiting for your final crown to return from the dental lab, a temporary crown is placed by the dentist. This is an important step for several reasons: It protects the tooth from sensitivity. prevents the tooth from breaking, and maintains the space by keeping the adjacent teeth from drifting.

If you are unable to see your dentist immediately, you can purchase temporary cement in the toothbrush aisle at your local pharmacy or grocery store. Also, you can try using Vaseline if nothing else is avaialble. I have also seen denture adhesive used successfully.