do i have a case?

root canal performed Dec '10 -- lower right molar #30 -- 3-4 roots in tooth, not 2 -- broke instrument (RC file) half way down 1 root -- was informed by dentist and he recommended finishing, leaving instrument behind -- i had continuous, slight pain, some difficulty chewing for 2-3 mths -- went back in, x-rayed, was told it was bite problem -- ground a little off crown -- problem continued -- at 5 mths, significant pain, swelling, couldn't chew on right side of mouth -- went in again, was told it could be instrument or fracture, but couldn't tell from x-ray if it was a fracture -- was also told by my dentist i would be referred to an endo for eval -- called my dentist back for referral, but dentist's partner intervened and said tooth was fractured and needed to be extracted -- my dentist offered to apply cost of root canal and crown ($1300) to the cost of extraction, implant, and another crown ($4800), leaving me with a bill of $3500 for their mistake -- i forced the issue and got a referral to a root canal specialist -- result was specialist said no evidence of fracture, there was probably a 4th root that my dentist didn't even see, and the broken instrument was causing infection (abscessed furcation) -- tooth is not salvageable and specialist recommends extraction, implant, and crown -- specialist wrote letter stating this which is in my possession -- also have in my possession a copy of x-ray clearly showing instrument in root -- currently on antibiotics -- gums are swollen -- can't chew on right side at all -- constant pain -- loss of sleep -- effecting daily performance -- etc, etc, etc.

not sure if this meets negligence criteria -- if they had done a competent root canal, i wouldn't have any problems, or incur any more expenses -- going on 7 mths now and probably will continue to get worse -- antibiotics have only been minimal help

insurance (HMO) precludes me from seeing another dentist without losing the offer on the table from my current dentist -- based on their previous performance, i don't really want these guys doing anything to my tooth -- ideally, i believe my dentist should pay the entire cost for another qualified endodontist to extract tooth, put in implant, and crown and/or whatever else you think might be applicable

it's not that he broke an instrument, but it looks like he missed the 4th root entirely and he had 3 opportunities to make it right -- 1) when it happened, 2) when i went in the first time with pain and he said it was a bite problem, and 3) when i went in the latest time and finally got a referral to somebody who actually knows what they're doing.

please advise -- will answer any questions

thank you