Why does our teeth feel numb and sensitive after we eat something sour?

Tooth sensitivity is tooth discomfort in one or more teeth that is triggered by hot, cold, sweet or sour foods and drinks, or even by breathing cold air. The pain can be sharp, sudden, and shoot deep into the nerve endings of your teeth. Tooth sensitivity occurs when the underlying layer of our teeth - the dentin - becomes exposed as a result of receding gum tissue (the protective blanket that covers the tooth roots). The roots, which are not covered by hard enamel, contain thousands of tiny tubules leading to the tooth's never center (the pulp). These dentinal tubules (or channels) allow the stimuli - for example, the hot, cold, or sweet food - to reach the nerve in your tooth, which results in the pain we feel.