If a tooth was healthy a dentist injured it while prepping it for a crown necessitating a root canal do I have any recourse He refuses to admit damage demands full pmt 800?

If the dentist was prepping the tooth for a crown, the tooth was not 'healthy'.

More than likely, the decay that necessitated the crown was closer to the nerve than was first realized, and when the dentist removed all the decay, the nerve was exposed and a root canal became necessary. This was NOT the fault of the dentist.

The fact that the nerve was exposed during the prep is actually a good thing for the patient. It would have been worse if the crown had been seated and permanently cemented in place and then the nerve symptoms became apparent. Then the brand new crown would have had to been drilled through to perform the root canal procedure or the tooth would have to be extracted and the crown would be lost as well.

As a patient, it is very easy to jump to conclusions and assume your dentist did something wrong when a complication like this arises. However, this type of unavoidable complication is fairly common. That is why your dentist is trained to manage the situation and perform the root canal as he did.

Your dentist did not 'cause' you to need a root canal. He simply revealed the fact during the prep, and it sounds like he handled it appropriately. You should appreciate the professional care you received under the circumstances instead of accusing him of causing you harm.

And yes, if his fee is $800 for the root canal, which actually sounds a bit low to me, you ought to pay it and be glad your dentist is competent enough to save a tooth that would certainly be lost without his skill.