I had a non-metal zirconium crown put in on a left lower molar #30 (I'm
using a chart here, hopefully I'm reading it right) about 1.5 years ago
and had various problems since.  The dentist had to repeatedly grind off
material from the crown due to pain when I bite.  It doesn't so much
resemble a molar any more.  Eventually the pain was reduced but now pain
has developed in the molar #3 above the crown on biting.  Examination
shows no cracks or other problems in this molar.

I feel like the crown "hits" the upper tooth from time to time.  The
material is very hard and I got a second opinion from a guy who felt I
should have it redone and go with cerec instead, because it's not as
hard as zirconium.  I am sensitive to metal and so that is out, I react
allergically to it.

I'm trying to make a decision here - will cerec hold up on a back molar?
 The current dentist who will be redoing the crown for me feels it
won't and I should stick with the zirconium.

I also don't really understand why the crown was hitting so badly on the
upper molar.  On the right side of my mouth the two molars 19/14 in the
same position butt against the last two 15/18. (wisdom teeth are gone).
 19 seems to be "shorter" than 18 while 14 is "taller" than 15, so they
all fit together.  I don't know if this is typical, the last two teeth
aren't level, but the crown on #30 went in level with the back #31
molar. It can't sit so high else I get all this pain.

I'm not sure how to convey all this to the dentist and the people who'll
make the new crown, or if they'd even listen.  I thought some sort of
impression would be made to show how the crown should sit but I'm not
sure it included the upper teeth.

I'm looking for advice on materials and how to get this crown done right
so I don't go through more pain, I've been through enough already.

thx,
Joe