Unflavored sparkling water is carbonated via dissolved carbon dioxide, which creates a mild acid (carbonic acid) that lowers the beverage's pH; scientific literature confirms that exposure to such acidic drinks contributes to dental enamel erosion when the pH drops below the critical threshold for demineralization.
Unflavored sparkling water is acidic and contributes to dental enamel erosion in vitro, though its real-world effect depends on exposure and individual factors.