The Root Cause
Enamel is a strong natural shield that covers the crown of the tooth, just above the gumline. The root of your teeth, however, are usually protected by the gum tissue, and the slightest bit of receding gum can expose it. Receding gums can be caused by poor oral hygiene, a hard toothbrush and inappropriate brushing technique, teeth grinding and clenching, or even aging.
Below the gum, the root has a very thin protective covering called cementum, but when the most sensitive part of the tooth underneath it – called dentin – is uncovered, your root may become vulnerable over time. When the root is exposed to temperature or fluid changes, the nerve in the pulp can be affected, which leads to sensitivity. So super hot or cold foods, and even substances that scratch your teeth, can lead to discomfort. In some people, sweet foods can create sensitivity too.