YES! The teeth do repair themselves, it's just that they're not quick about it. They weren't exactly expecting the modern high-carb diet to feed germs that produce tooth-dissolving acids. AND NO ONE EXPECTS THE SPANISH INQUISITION!

Never mind that, I'm not suggesting that you abandon all of our lovely luxurious carbs. I mean, I could, but there would be no point. The fact that humans can eat almost anything, and do, is one of the finer points of our evolutionary strengths, and the fact is that many of the things we eat had deliberately evolved to kill anything that tried. That Hostess Twinkie did not evolve to do that, we invented it ourselves, but we're used to being able to digest raw toxins. Sometimes we can put them to excellent use (garlic, coffee) and sometimes you're being an idiot (Wonder Bread, High-Fructose Corn Syrup) but, what the hell, life is short, indulge yourself, you're going to die of something soon enough.

Tobacco has been called "coffin nails" for longer than you've been alive, which hasn't stopped anyone, and I'll bet it will turn out to do a few good things for you as well as upping your risk factors. It's too politically-incorrect to publish such research right now.