Caffine Free Diet Soda

I find that when I am dieting a Caffine free diet soda really helps me kill my cravings for carbs at night. Just wondering if there are any bad sides to drinking it besides the whole "cancer" thing. I also heard that it is almost as good as water? Also is Caffine free diet soda bad for your teeth just like normal soda? I would say no because there are no sugars, but any help would be much appreciated. THanx

drink diet rite
no caffine
no sugars
no sodium
none of that shit thats in dr. pepper either