Is wine bad for your teeth?

Yes and no, judging from my own experience and from my dentist. If I taste a lot of wines (especially whites) I certainly have the impression that it gets to my teeth. Brushing the teeth (or eating something sweet) after tasting a few hundreds wines is not nice thing. It can feel horrible. It’s the acid of course. I have also heard people strongly recommend that you do not brush your teeth after a serious wine tasting because the teeth defences (the enamel) has been weakened so you risk damaging the teeth. On the other hand my dentist says that it is an excellent way to keep your teeth clean. For a more in depth view you can read the two articles on Wines and Vines
Article 1
Article 2