What Causes Sensitive Teeth and How to Treat It

Hot vs cold sensitivity points to different problems — here is how to tell which and what to do

If hot coffee makes you wince or cold water sends a sharp jolt through a specific tooth, you have tooth sensitivity. About 1 in 8 adults has it to some degree. Most cases are manageable; some signal a problem that needs prompt attention. The clinical insight that determines treatment: cold sensitivity that fades quickly usually points to gum recession or enamel wear, while cold sensitivity that lingers more than 30 seconds or heat sensitivity often points to a dying nerve. Different problems, different solutions. From Dr. Aqil Valika at Bliss Dental Center in St. Charles, IL, here is how to figure out what is happening and what to do about it.

The Mechanism — Why Teeth Get Sensitive

Healthy enamel is the most mineralized substance in the human body — harder than bone. It does not transmit temperature to the underlying nerve. Beneath enamel sits dentin, a porous tissue with thousands of microscopic tubules running from the outer tooth surface inward to the pulp (the nerve and blood vessel chamber).

When dentin is exposed (because enamel has worn or because gums have receded exposing the root surface), the dentin tubules transmit temperature changes directly to the pulp. Cold or hot fluid moves the fluid inside the tubules, which mechanically stimulates the nerve. That is the sharp pain you feel.

Treatment works by either sealing the dentin tubules or addressing whatever damaged the enamel/gums in the first place.

Cold Sensitivity That Fades Quickly

If cold drinks cause a quick jolt that fades in seconds, the most common causes are:

Gum recession. Gums have pulled back, exposing root surfaces. Roots have no enamel — they are dentin covered by a thin layer of cementum that wears off easily. Common in adults over 40, especially with aggressive brushing or gum disease history. Treatment: fluoride toothpaste (rebuild surface mineralization), desensitizing toothpaste with potassium nitrate or stannous fluoride (blocks dentin tubules), and addressing the underlying recession (gentler brushing technique, soft-bristle toothbrush).

Enamel wear from grinding. Bruxism wears the chewing surfaces. Treatment: custom night guard + desensitizing toothpaste.

Recent whitening. Both in-office and take-home whitening cause temporary sensitivity for 24-72 hours. Resolves on its own.

Acid erosion. Frequent exposure to acidic foods and drinks (citrus, soda, wine) erodes enamel. Treatment: limit acids, rinse with water after consuming, fluoride toothpaste.

Most “fading cold sensitivity” cases respond well to home care — desensitizing toothpaste used daily for 4-6 weeks usually resolves it.

Cold Sensitivity That Lingers More Than 30 Seconds

This is the warning sign that warrants prompt evaluation. Lingering cold sensitivity (the pain stays after the cold is gone) suggests pulp inflammation — the nerve inside the tooth is being irritated by something more serious than surface dentin exposure. Causes:

Deep cavity reaching the pulp. Decay has progressed near or into the pulp chamber. Treatment: usually root canal or, if caught early enough, a pulp capping procedure with a deep filling.

Cracked tooth syndrome. A crack extending toward the pulp causes intermittent lingering sensitivity, often with biting pain. Treatment: crown to hold the tooth together, root canal if the crack reaches the pulp. See our cracked tooth page.

Failing old filling. An old filling has developed decay underneath, irritating the pulp. Treatment: replace the filling, possibly root canal if pulp is significantly inflamed.

Lingering cold sensitivity warrants a dentist visit within 1-2 weeks. The cold-test response is one of the best indicators of pulp health.

Heat Sensitivity — Often a Dying Nerve

This is the clinical insight worth knowing. While cold sensitivity has many causes (most benign), heat sensitivity often signals a tooth in trouble. The pulp is becoming non-vital — the nerve is dying. Hot drinks cause gas expansion inside the pulp chamber, pressing on the dying nerve and causing sharp pain.

Heat sensitivity that develops suddenly, especially in a tooth with a large old filling or a known crack, usually means the pulp is in late-stage inflammation or necrosis. Treatment: root canal in nearly all cases. Without intervention, the pulp will fully die and an abscess will eventually develop.

If you have heat sensitivity in a specific tooth, especially if you can feel pressure or pulsing in that tooth, schedule an evaluation soon. See our root canal page and signs you need root canal blog post.

What to Try First (Home Care)

For mild generalized sensitivity:

Switch to desensitizing toothpaste — Sensodyne, Colgate Sensitive, or stannous fluoride formulations. Use twice daily for 4-6 weeks before evaluating effect.
Soft-bristle toothbrush — medium and hard bristles cause gum recession over time.
Modified brushing technique — gentle circular motions, not aggressive scrubbing.
Fluoride rinse — daily 30-second rinse after brushing.
Limit acidic foods/drinks — citrus, soda, sparkling water, wine. If consumed, rinse mouth with water afterward.
Address grinding if applicable — see night guard page.

If sensitivity does not improve after 4-6 weeks of consistent home care, or if it is localized to a specific tooth (especially with biting pain or lingering response), schedule a dental visit.