Birmingham University (the one in England) reports that "fizzy drinks" and "sports drinks" both cause "tooth erosion" due to the relatively high acid content. They recommend brushing your teeth.
When I was in Sixth Grade (circa 1978), I ran a science project on the effect of Coca-Cola on various materials. I put various objects (pennies, teeth) into Coca-Cola, dilute phosphoric acid (an ingredient in Coke), and distilled water. Conclusion: The Coke and the phosphoric acid dissolved the teeth and cleaned the pennies. Ergo, the danger ingredient was the phosphoric acid. I recommended brushing your teeth.
They stole my research! I want tenure!
I did reference the project in Ninjas, Piranhas, and Galileo.