Tea and tooth health?

I had a dentist visit tonight and sad to say, my enamel isn't as thick as it used to be. I stumbled across this article ( http://teaperspective.com/how-tea-can-s … th-enamel/ ) and it sounds like the fluoride found in tea can be beneficial for a healthy smile (Here's a direct link to the research: http://onlinelibrary.wiley.com/doi/10.1 … /abstract) But I've also done a bit more research on fluoride after reading this and it sounds kind of controversial. Is there enough of it in tea for it to be good or bad either way, or does it mostly depend on the water I'm using?