Teeth have a hard external structure (enamel and dentin) that protects the internal soft tissue, called dental pulp, which is made up of nerves and small blood vessels.
The teeth and the structures that surround them have nerve endings such that when any type of aggression, damage, or disease occurs, they send signals to the brain as an alert and defense mechanism that indicate that something is wrong.
1. Extreme cold or heat
The dental pulp is sensitive to changes in temperature. Very cold or very hot foods can cause sensitivity, which under normal conditions should disappear when the stimulus is removed.
2. Gum recessionThe roots of the teeth are usually covered by gum tissue. Sometimes, brushing the teeth horizontally can cause the gums to recede and the roots to be exposed to air and temperature changes, causing pain.