There is not a warranty with crowns, and as you know, they aren't
cheap, and dental insurance is almost worthless.
Well, apparently there is a warranty on crowns done by reputable
dentists. I had a crown come off this last summer. I went to my
dentist in Ozark County to have it glued back on. He looked at it and
said the back had slightly broken. He put on a temporary crown and
said keep that broken one and take it back with you when you return to
Phoenix, there is a several-year warranty on crowns. I don't recall if
he said four or five years.
To verify, I e-mailed the dentist here and he confirmed there would be
no charge. After I returned here he did a new impression and ordered a
new crown made by the lab. He then installed it. No charge.
I have also had crowns just come off, not broken. They are reinstalled
with no charge.