Hi Joey,
I read your story very carefully. This was my observation:
1. That you are very nice, naive and gullible(sorry for being honest)
2. That she just used you financially.
3. That she is not the woman for you, move on, find someone with a lot less baggage, and one who'll appreciate you.
4. She is very childish, ungrateful and a total loser.
5. Forget the money you gave her for dental work. You can't recover that, you did not have any agreement signed that she'll pay for it back.
6. Stay away from her, get busy with more productive projects
7. It is not a good idea to give big sums of money during courtship.
it was not your obligation to fix her teeth.
8. Learn this lesson, don't get involved with a woman who has lots of issues.