Many sodas and diet soft drinks approach the pH level of battery acid in terms of corrosiveness and erosion of tooth enamel. Our susceptibility to tooth decay and cavities has much more to do with what we put in our bodies, rather than regular visits to our dentist or even how often we brush our teeth. If you want to prevent tooth decay, a ‘great’ idea is to stay away from acidic beverages which dissolve tooth enamel and offer no nutritional value to your body.
Source: http://preventdisease.com