Crown Lengthening Question

I had a root canal a few months ago. The dentist at the time filed down the tooth (not sure if this is typical for a root canal). This was done on tooth #31. The temporary crown they gave me fell off later that day. I went back in and it fell off again the same day. Both times without even eating. When i went back in 2 weeks later for the actual crown, they had a very hard time getting it to stay on. They mentioned that the original dentist took away too much of the tooth. However, the crown did stay on for about 3 weeks. Then I was chewing a cookie and it popped off. When I went back in they could not get the tooth to stay on. The new dentist said "you have a really small tooth" referring to remaining amount of my tooth. They eventually referred me to get a crown lengthening which I'm told is painful and costs about $800. My question is that why should I pay for this when it  was the original dentist that took away too much of my tooth? I didnt know the procedure and she never asked me if it was ok, she just acted as if it was necessary. Is there anything I can do here to not pay this, and is this whole procedure even necessary?

[scottma]

The real meaning of crown lengthening is to establish biologic width, instead of increasing length of clinical crown. If tooth #31 was overreduced, core built up can generally restore adequate clinical crown length. Seeing a prosthodontist or experinced restorative dentist is advised.