Lets look at what you're drinking: pH vs Sugar
Many patients realize that soda can cause decay. However, we commonly see patients that switch to diet soda thinking that they are making a better choice for their teeth. We actually see just as much decay with diet and sugar free carbonated drinks..ITS TRUE! Even carbonated water! One important factor in decay is actually the pH in our mouth. Carbonated beverages are actually very acidic. Basically, any time you take a sip of anything other than water, the pH drops in your mouth. This acidic pH actually weakens the enamel of the teeth and makes them more susceptible to decay.
So, when we talk about what you're drinking it is important to think more about frequency (how many times you're exposing your teeth to acid) than the amount you're actually drinking. A common misconception is that if you spread out 1 can of soda throughout the day, its better for your teeth. That is actually false. By sipping on your drink you're actually keeping your mouth and teeth in a constant acidic pH that doesn't allow your teeth to recover. Therefore, if you decide to drink anything other than water it is best to drink it within thirty minutes, then swish with water. Swishing with water after is a great way to neutralize the acidic pH that the beverage caused in the mouth. We always want to do our best to keep that pH neutralized. Bottom line, drink water as much and as often as you can and if you choose another option, drink it quickly!
Keep in mind that the enamel of our teeth starts to weaken at a pH of 5.5!