Dentist denying forwarding my records/x-rays due to unpaid bill?

When I lived in Seattle, I saw a dentist once, and his son (also a dentist with his own practice) twice. Once for routine, again when I was sure I had a cavity, and again when the tooth with the cavity had pain. I was told it was not a cavity, and that it was "just decay" and that they would "put a watch on it." Now, my insurance was giving them hell about paying, even though I had full dental insurance. They had to resubmit for each visit many times. The last time, though I was still covered and verified this with insurance, the office claims insurance denied the claim, and that I owe them $240. I have not paid this due to current financial strain. (You know, keeping electricity and water on.) Anyway, just recently, this tooth I was having issue with BROKE. Now, I take insanely good care of my teeth, to the point of where strangers compliment my 'beautiful smile.' Now that I'm back in Massachusetts, I went to my family dentist, who's great, the day after the tooth broke, and was told I needed a root canal and a crown. :( Cue a bill of almost $3,000. My dentist wants those x-rays and records. *I* want those X-rays and records because if this was caused by negligence on their part, of their not finding an obvious cavity and ignoring my pleas for help and a filling...I will be getting an attorney to insure these dental bills are compensated. :( So my major question is, do they legally have the right to deny me access to my dental records due to a bill being unpaid? I *was* insured and do not know why the insurance was denied (we had separate dental, not just supplemental) for a routine checkup. I thought that under the Freedom of Information Act, any records they had on me could be obtained at any time, regardless of financial standing, since this impacts my oral health, and so, overall health. Any help would be appreciated, and sorry for the long-windedness; I just wanted to cover all bases.
--------------------
Almost all State laws say that a dentist cannot refuse to forward your records or copies of them for any reason including an unpaid balance. I don't believe the Freedom of Information Act has anything to do with this problem but almost all State Dental Boards have it specifically written into the dental laws of their state. Google the dental board of the specific state to find it.
Source