Tooth sensitivity occurs when the underlying layer of your 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 nerve 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 you feel.