Tooth sensitivity happens when the protective enamel on teeth is damaged. Enamel protects the more delicate part of the tooth, called dentin, that lives below the gumline. Dentin has tiny tubes that connect to the tooth’s nerve centre. So when it’s exposed to hot, cold or acidic food or beverages, the result is a shocking pain.
Your dentist needs to know if your teeth are sensitive because the causes can include:
Receding gums
Gum disease
Worn tooth enamel
Teeth clenching
Worn fillings
Information as per the ODA https://www.oda.ca/oral-health-basics/oral-conditions-diseases/tooth-sensitivity/