this sounds like a mild dose of paranoia. No matter how unaware a dentist is of the harm he could do, I sincerely doubt a dentist would ever intentionally cause cavities in a patient.
Directing your anger towards your dentist is not unusual but isn't necessarily going to make your teeth any better. Clay baths draw toxic metals out of the body.
I think that getting in touch with the emotions that are aroused by thinking about it is ok, but I wouldn't take too much notice of the objects that your emotions attach to.
Emotions like anger sometimes want revenge and a simple answer to a problem, but they don't always get one. I hope you get all the good things you ever want from your teeth.