In short: Tooth sensitivity to hot and cold usually means the protective enamel has worn thin or the gums have receded, exposing the softer layer beneath that connects to the nerve. Common causes are hard brushing, acidic foods, grinding, gum recession and cavities. Desensitising toothpaste helps mild cases; a dentist can treat the cause.
That sharp, brief jolt when something hot, cold or sweet touches a tooth is dentine sensitivity, and it’s very common. It happens when the tooth’s inner layer — dentine, which contains tiny channels leading to the nerve — becomes exposed, letting temperature and sweetness reach the nerve. Normally dentine is protected by enamel above the gum and by the gum itself; sensitivity means that protection has been lost somewhere. Common causes include:
- Worn enamel — from brushing too hard, using a hard brush, or acidic foods and drinks that erode enamel.
- Gum recession exposing the root, which has no enamel and is more sensitive (often from hard brushing or gum disease).
- Teeth grinding, which wears enamel.
- A cavity, cracked tooth, or a lost/leaking filling.
- Temporary sensitivity after whitening or a recent filling, which settles.
For mild, general sensitivity, self-help often works: use a desensitising toothpaste regularly, switch to a soft brush and gentle technique, avoid acidic foods, and don’t brush straight after acidic things. These reduce sensitivity over a few weeks.
But if the sensitivity is sharp, focused on one tooth, or lingering, it may signal a cavity or crack that needs treatment — worth getting checked rather than just coping.
If sensitivity is bothering you, book an appointment — our teeth sensitivity treatment finds the cause and gives lasting relief.