Sipping on sodas, or anything other than water, all day long can soften tooth enamel leading to tooth decay. The normal pH of saliva ranges from 5.6 to 7.9. As food and drink enter the mouth, the pH of saliva lowers to a more acidic state causing an environment for tooth decay. Sipping on a soda all day long leaves your mouth in an acidic environment. Therefore, it is best to drink the soda at once, or with a meal. Rinsing your mouth out with water, chewing sugar free gum that contains xylitol, and brushing your teeth with fluoride tooth paste are all ways to help your mouth return to a normal, decay free solution.