however friendly web dentist man says this:
It is good for your general health and well being to drink plenty of water. The problem with drinking flavoured carbonated waters is not that it will cause your teeth to decay but that it may cause tooth erosion. Tooth erosion is the chemical wearing away of enamel (white hard substance on the outside of a tooth). Flavoured carbonated waters are acidic and may cause the outside layer of enamel to demineralise and dissolve in your saliva.
The potential of carbonated drinks to cause enamel erosion depends on the acidity level of the drink and on the length of time the drink is in contact with your teeth. Drinks with ph less than 7 (acidic) that have prolonged contact with your teeth have potential to cause harm;.the lower the ph the greater the potential for harm.
The occasional drink of this type of water is not a problem but if you drink it frequently each day, it may become a problem. Some of your teeth may become sensitive near the gum margin where the enamel layer is thin and your front teeth may become more translucent. When cleaning your teeth, be careful to allow the enamel remineralise after drinking any carbonated drinks by waiting at least an hour before brushing with fluoride toothpaste.
You can also further minimise harm by drinking carbonated drinks through a straw.