What that really means is that while you're not downing the extra sugar and other acids, going hog-wild on 12-packs of Perrier and bubbly waters still isn't the best idea.
"There is a theoretical risk of tooth erosion, but the drinks would have to be consumed over a long period of time,” Damien Walmsley, a professor of dentistry at the University of Birmingham told The Atlantic. “My advice is to keep acidic drinks to meal times, and if you have to sip drinks between meals, then plain water is the safest.”
Additionally, flavored seltzers often get that flavoring through the inclusion of citric acid, thus making the drink worse for your teeth.
In the end, seltzer and sparkling water aren't THAT bad for your teeth. But if you're truly concerned about your pearly off-whites, well, stick to water. And maybe drink through a straw.