According to many dentist if you have sensitive teeth, it could be due to exposed nerve roots but often it is due to receding gums. Sensitive teeth are most noticeable to cold and tooth liquids. The best thing to do is to lay off on the tooth whitening products, tartar control, and baking soda toothpastes because they are abrasive and some contain phosphates. Abrasive products and products containing phosphate are the two causes of sensitive teeth. Brushing too hard is also a cause as it leads to recessed gums.