So did you have a question?
FYI, your previous post, isn't liked to this one,, whether it'll be seen is hit or miss. You might try to shorten your post to fit it in one submission--it IS enough space if you limit yourself to the main points.
NOT LEGAL ADVICE. FOR EDUCATION AND INFORMATION ONLY. Mr. Rafter is licensed to practice in the Commonwealth of Virginia and the US Federal Courts in Virginia. There is no implied or actual attorney-client relationship arising from this education exchange. You should speak with an attorney licensed in your state, to whom you have provided all the facts before you take steps that may impact your legal rights. Mr. Rafter is under no obligation to answer subsequent emails or phone calls related to this matter.
You may have exceeded the time limit for challenging the charge through the credit card company, but that does not mean you are outside the statute for suing the dentist in court. It is doubtful you can force him to give you the deposit now so as to permit you to hire the other doctor. But you can sue him for what you lost.
Shift focus from the dispute to the Dentist's malpractice insurance. You have an expectation and it was not met. This does not mean there was malpractice. Did you pay for the two failed implants? Or, did the Dentist refund you for the failed work? You should consult a professional malpractice attorney.