Carbonated water typically have a pH around 4, adding lime juice may reduce it slightly further, but not by a huge margin. Acidity of most beverages on its own

Carbonated water typically have a pH around 4, adding lime juice may reduce it slightly further, but not by a huge margin. Acidity of most beverages on its own is usually not problematic as saliva (buffered at 6.5 pH) rapidly restores normal pH. It does become an issue if the salivary glands are damaged (as in the case of meth users) or stomach acid comes into contact with teeth.(severe acid reflux or bulimia) However these cannot be considered normal. The number one cause of dental cavities is always sugar.