Is there anything I can do about a dentist who apparently did work on my teeth a while back when he didn't need to?

If you have a dentist willing to testify to that in court, against the other dentist, you can sue for malpractice, and possibly also for assault.  If you can't find a dentist witness, you can still write a letter of complaint to the state board that licenses dentists, and they will investigate.

Any kind of medical or dental treatment requires "informed consent."  Otherwise, the intrusion on your person isn't legally different from someone punching you on the street.  If the dentist told you that you needed the work, when he knew that wasn't true, it's legally impossible for him to have informed consent for the treatment, because informed consent has to be based on truthful information.