You are in a complex situation that most of us are not equipped to analyze so we can't do anything more than guess. But it seems like if you continue to do the right things you could find yourself in Dental school.
In regards to not taking any more undergrad classes, I am not sure, but it might not be a terrible idea to get your feet wet again and show you haven't lost anything by taking a couple tougher bio courses. Your 3.8 gpa from your original undergrad is definitely worth something, without that you would not have a chance.
My complete guess is that a lot of dental schools are going to have a problem with you being dismissed from med school, but you will be able to find a school willing to give you a shot. I would start by calling dental schools and telling your story and ask them what you can do to prove yourself in their eyes.
Best of luck to you, I hope you find your path.