Do diet sodas still rot your teeth?

One of the major ways you can get tooth decay is bacterial growth on the teeth, feeding off sugars and other food particles left behind. Since diet sodas contain fake-sugar meant to be undigestible, do they no longer support bacteria growth? (Obviously you’d still have to worry about damage from the acids in the soda itself)

<<Q. But even diet soda contains acid from the carbonation (carbonic acid) as well as citric acid and even other forms of acid added to enhance the flavor. Why is it that diet soda doesn’t cause decay??

A. All the non sugar related acids in soda (including diet soda) are so soluble in water that they are washed off the teeth almost immediately before they can cause much decalcification of the tooth structure. On the other hand, the sugar in regular soda is very sticky and remains on the teeth for a long time. In addition, the bacteria in plaque use sugar as a raw material to create dextrans which is the viscous sticky stuff that makes plaque adhere to the teeth. The dextrans have the property of absorbing more sugar which is turned into acid by the plaque bacteria causing the plaque to remain acidic for twenty minutes or more after each exposure to sugar.>>

I do hope it’s true, since I’ve been seeing these “acid wear” commercials (GlaxoSmithKlein trying to sell their special toothpaste) and have started to worry.