Sensitivity is not an emotional quality in the mouth but an annoying, and sometimes debilitating, nerve response that really bugs the brain! Essentially the surface that covers the dentine is lost and this is not good. The dentine is the layer under the enamel that covers the tooth above the gum. The dentine forms the root and is covered by bone the gum and bone where the enamel ends. The dentine is the layer that protects the nerve. This amazing dentine is constructed of mini tubes (tubules) that allow the tooth to bend and has cells within these tubules that connect (talk) to the nerve.

That’s the normal set up.

The moral of the story is the dentine is not meant to be exposed AT ALL to the hostile environment of the mouth, period!  

Some are genetic, when the tooth enamel does not form properly or is missing. Other times it can be caused by underlying medical conditions, or through trauma.

There are underlying dental conditions such as grinding, dry mouth, and poor use of appliances, such as dentures.  

However, we clever humans have multiple of other ways of causing this terrible neural response of the exposed dentine. 

These include chemicals we ingest such as acids, sugars, caffeine, and smoking.

Even a toothbrush can be a weapon of tooth destruction.