The part of your teeth that is above the gumline, are covered with a layer of protective enamel, while the roots below your gumline are protected by a material called cementum. Underneath the enamel and cementum is dentin, which is less dense than the protective coverings. The dentin contains microscopic canals called dentin tubules, and when enamel or cementum wears away or becomes damaged, it exposes the dentin. When your gums recede and expose the dentin, the tubules allow fluid to flow into them and are affected by heat and cold when can cause the nerves in the tooth to have sensitivity and pain.

• Consuming too many acidic foods or beverages
• Brushing your teeth too aggressively
• Overusing certain tooth-whitening products

>However, with extremely sensitive teeth, the more likely causes are those that expose more dentin, such as:

• Tooth decay
• Worn fillings
• Broken or fractured teeth