Recently one of my friends who had a very bad habit of eating spicy foods , drinking carbonated drinks and smoking had undergone teeth whitening few months back. Nicotine stains really made his teeth to appear as those of a devil. Now, although she hasn't quit smoking but is strictly following the doctor's diet chart. Junk foods has been replaced by fresh and juicy fruits, even she no more drinks any carbonated beverages. Her smile is now much appreciable than before!