Skip to content

Why Are My Teeth Sensitive to Cold? Causes, Relief and When to Book

Teeth sensitive to cold have lost some of their cover, so cold reaches the nerve through the dentin under the enamel. Worn enamel and receding gums are common causes, and a cavity, a crack or an inflamed nerve can cause it too.

Straight-on close view of the lower front teeth in glossy deep pink gum, the gum receded on the two central incisors to show a band of yellow root surface, the pulp and nerve inside those two teeth glowing pale blue through a see-through layer and an icy blue mist with frost crystals drifting in from the left, on a deep navy background with a warm gold glow

Here is what causes it, what helps at home and when to call.

Key takeaways

  • Exposed dentin causes the twinge. Tiny channels in it carry the cold straight towards the nerve.
  • Gentle care comes first. A soft brush and a toothpaste for sensitive teeth help many mild cases.
  • Lingering pain is a warning sign. An ache that outlasts the cold or one tooth that throbs needs an exam.

Why does cold make your teeth hurt?

Labelled diagram titled How Cold Reaches the Nerve showing a cross-section of a lower back tooth in pink gum and porous jawbone with its pulp, nerves and blood vessels, the gum and bone reaching the enamel edge on the left but sitting lower on the right so a band of yellow root surface is bare, and a gold-framed magnified circle of the dentin with tiny parallel channels and blue arrows entering them, labelled Enamel, Dentin tubules, Exposed root, Gum recession and Pulp and nerve
Once the gum pulls back, cold travels through tiny channels in the root towards the nerve.

Cold hurts when it reaches dentin, the layer under your enamel. Dentin is full of tiny tubes called tubules that lead towards the nerve in the centre of the tooth.

Enamel covers the crown of a tooth and gum covers its root. When either one wears away, cold from a drink or winter air travels down those tubes. You feel a short and sharp jolt that comes back with the next cold mouthful, which dentists call dentin hypersensitivity.

Premolars and first molars react most, along with any tooth whose root shows at the gum line.

What wears away the protection?

Thin enamel, receding gums and damaged teeth are the main causes, and more than one can be at work.

  • Acid wear from citrus, pop, vinegar or acid reflux softens and thins the enamel over time.
  • Brushing too hard with a stiff brush wears enamel down and pushes the gums back.
  • Receding gums bare the root, which has no enamel to protect it. Gum disease, grinding and thin gum tissue all pull the gum line back.
  • Grinding and clenching at night wear teeth flat and can crack them.
  • A cavity, a crack or a worn filling opens a path into one tooth and makes it react on its own.
  • Recent whitening or dental work can leave teeth tender for a short time.

Is it a simple twinge or a sign of something more?

A twinge that fades within seconds points to exposed dentin. Pain that lingers after the cold is gone, throbs on its own or keeps coming from one tooth needs a dental exam soon.

Lingering sensitivity can mean the nerve inside the tooth is inflamed or infected. A tooth that also hurts with hot drinks is a stronger warning than cold alone.

Call us at (905) 309-5757 for the soonest available appointment if sensitivity suddenly gets worse. The same goes for a cracked or broken tooth and pain that keeps you awake. Do not wait for the pain to become severe, and call about any severe toothache or gum swelling too. When the clinic is closed, go to the nearest hospital emergency department or an emergency dental service.

Call 911 or go to the nearest hospital emergency department if you have trouble breathing or swallowing, severe facial swelling, swelling spreading toward the eye or neck, uncontrolled bleeding, a serious facial or jaw injury, or a fever with worsening swelling or illness.

What can you do at home?

A toothpaste made for sensitive teeth and a lighter touch with your brush calm many mild cases. Ask your dental team before you use these products for a child.

  • Use a sensitivity toothpaste every time you brush. Ingredients such as potassium nitrate and strontium chloride help block the signal to the nerve.
  • Brush with soft bristles and small strokes along the gum line. An electric brush with a pressure sensor warns you when you press too hard.
  • Ask your dental team about a fluoride rinse or gel, which can help block the open tubules.
  • Rinse with water after acidic food or drinks. If whitening sets off sensitivity, stop and call your dental team before you carry on.

How does a dentist treat sensitive teeth?

Close view from the cheek side of a lower canine and premolar in pink gum, the gum receded on the premolar to show a band of yellow root surface and a thin applicator brush with a blue end at the frame edge painting glossy pale yellow fluoride varnish over half of the bare root, with a gold-framed inset of magnified dentin whose tiny channels are sealed at the surface by the varnish
Fluoride varnish brushed over a bare root helps protect it and block its tiny channels.

Your dentist finds the cause first and then treats that, not just the twinge. At Grimsby Lake Dental in Grimsby the exam tests how the sore tooth reacts to cold, pressure and biting. X-rays are taken when they are needed.

  • Fluoride varnish from a fluoride treatment visit protects root surfaces left bare by receding gums.
  • A filling or a crown repairs a cavity, a worn filling or a cracked tooth.
  • Gum care treats the gum disease behind recession. Advanced cases go to a gum specialist by referral.
  • A night guard takes the wear when grinding is thinning your teeth.
  • Root canal therapy treats a nerve that infection or damage has harmed too far to recover.

The team goes over the expected cost with you before any treatment.

Cold drinks still making you wince? Book an exam or call (905) 309-5757.

Frequently asked questions

Why are my teeth suddenly sensitive to cold?

New sensitivity can follow whitening, a new filling or a spell of brushing too hard. It can also mean a new cavity, a crack or receding gums. Call if it suddenly gets worse, and book a check either way. If you are pregnant, tell your dental team.

Will sensitive teeth go away on their own?

Sensitivity from whitening is temporary for most people, and your dental team can adjust the plan. Twinges from worn enamel or receding gums need daily care and a dental check of the cause.

Why do my teeth hurt more in winter?

Cold air you breathe in reaches exposed dentin just as a cold drink does. The same home care and the same warning signs apply.

Which toothpaste helps with cold sensitivity?

A toothpaste made for sensitive teeth, with ingredients such as potassium nitrate or strontium chloride, helps block the signal to the nerve. Use it every time you brush.

Can brushing too hard cause sensitivity?

Yes. A stiff brush and hard strokes wear enamel down and push the gums back. Switch to soft bristles and small strokes along the gum line.