A dentist friend of mine once told me that having a habit of using straw will preserve your teeth. Especially when drinking sugary drinks. The logic behind it is that when you use straw the drink will pass trough your teeth and directly into your throath hence will not in contact with the liquid.
Although i'm not a big fan of this idea because I think plastic straws are bad for the environment, but perhaps you can try using reusable straw that's made from solid plastic or wood or something.