Pull my dog's tooth?

My dog has a broken upper molar.  When she had her root canal done,
she had a surface "restoration" performed also to replace a piece that
had broken off the side (with a dental resin).  A month or two later,
the restoration fell out.  We had it done a second time; and she lost
it a second time.  The original root canal work seems fine.  The only
problem is that the broken tooth surface harbors tartar and plaque and
causes gum irritation.  Now our dog-dentist suggests we have a crown
made; but also warns that crowns can be broken or lost too, and
considering our dog's history, he's not making any guarantees.  I
asked him about pulling the tooth, and he says that pulling the tooth
would be a "last resort".  I asked several more questions:
- Would pulling the tooth solve her gum irritation problem? Yes.
- Could pulling the tooth cause other problems...i.e.. overstress her
other teeth, etc? Probably not.
- Would pulling the tooth leave a 'hole' to trap food, harbor bacteria
etc? No.

Based on his answers, I have trouble seeing why it is a 'last resort'.
 In my view, we've given it a shot.  We've tried to repair the tooth
twice, and failed.  Yes there are other procedures we can try, but
there is a good chance they might fail also.  Meanwhile, my dog is in
pain and will have to undergo general anesthetic at least two more
times if we have a crown done (more if it, too, fails).  I say its
time to throw in the towel and pull it.  What do you think?

More details about my dog:
female, spayed, 3 yr old, mixed breed, 36 lbs, healthy, active, but
not an obsessive 'chewer'.

Any advice appreciated,
Ken