What is Dentin Hypersensitivity?

What Causes Sensitive Teeth?

Tooth dentin contains thousands of tiny fluid filled pores called dentin tubules. When these pores are exposed to the oral enivronment, things like cold, air pressure, sugars, and touch can cause the fluid in these tubes to move and produce sharp pain and sensitivity. A lot of other conditions can also cause pain, so it is important for your dentist to make the definitive diagnosis of dentin hypersensitivity.
Not all exposed dentin is sensitive, and in order for you to experience dentin hypersensitivity two things need to happen:

1. Lesion Localization – Obviously tooth dentin must first be exposed to the oral environment. Usually this happens due to gum recession that exposes the dentin on tooth roots, but it can also occur with excessive tooth wear and tooth decay.
2. Lesion Initiation – Microscopic studies have shown that sensitive teeth are different than non-sensitive teeth. They have larger pores and are missing a protective protein coating call a smear layer that normally covers the surface of exposed dentin. Once areas of exposed dentin become initiated though removal of the smear, their pores are open to the environment and can cause pain. The best way to treat dentin hypersensitivity is to work to plug up these pores and to maintain the smear layer.