What Is Tooth Sensitivity?
Tooth sensitivity — also called dentin hypersensitivity — is a sharp, sudden pain or discomfort that occurs when teeth are exposed to certain stimuli. These triggers typically include hot or cold temperatures, sweet or acidic foods, cold air, and even tooth brushing. It's one of the most common dental complaints and can significantly impact quality of life.
Why Teeth Become Sensitive
Your teeth are protected by a hard outer layer called enamel. Beneath the enamel is a softer layer called dentin, which contains thousands of tiny tubules leading to the tooth's nerve centre (the pulp). When the enamel is worn down or the gum line recedes, these tubules become exposed. Stimuli can then travel through the tubules and trigger the nerve, causing pain.
Common Causes of Sensitivity
- Enamel erosion: Caused by acidic foods and drinks, acid reflux, or excessive brushing with hard-bristle brushes.
- Gum recession: Exposes the root surfaces, which lack enamel protection. Often caused by gum disease or aggressive brushing.
- Teeth grinding (bruxism): Wears down enamel over time, often during sleep.
- Cracked or chipped teeth: Create pathways for stimuli to reach the nerve.
- Tooth decay or cavities: Damage the enamel, exposing sensitive dentin.
- Teeth whitening: Peroxide-based products temporarily increase sensitivity in many people — this usually resolves within a few days.
- Recent dental procedures: Fillings, crowns, or cleanings can cause temporary sensitivity.
Diagnosing the Source
Not all tooth pain is sensitivity — it could be a cavity, a cracked tooth, or an abscess. If sensitivity is severe, localised to one tooth, or persists for more than a few seconds after the trigger is removed, see a dentist. Lingering pain often indicates a deeper issue requiring treatment.
Prevention Strategies
- Use a soft-bristle toothbrush and brush gently using circular motions — not aggressive back-and-forth scrubbing.
- Limit acidic foods and drinks (citrus, soft drinks, vinegar-based foods). When you do consume them, rinse with water and wait 30 minutes before brushing.
- Use a fluoride toothpaste — fluoride strengthens enamel and helps remineralise weakened spots.
- Wear a nightguard if you grind your teeth. Your dentist can fit you for one.
- Treat gum disease promptly to prevent further recession.
- Stay hydrated — saliva is your mouth's natural defence against acid and bacteria.
Relief Options
Desensitising Toothpaste
Products containing potassium nitrate or stannous fluoride are specifically formulated to reduce sensitivity. Potassium nitrate calms the nerve fibres inside the tubules, while stannous fluoride physically blocks the tubule openings. Use them consistently — results typically build over several weeks.
Fluoride Treatments
Your dentist can apply professional fluoride varnishes or gels to strengthen enamel and reduce sensitivity. These are more concentrated than anything available over the counter.
Bonding Resin
For significant exposure of root surfaces, a dentist may apply a bonding resin to seal the exposed dentin — providing immediate and long-lasting relief.
Dietary Adjustments
Temporarily reducing consumption of cold, hot, sweet, or acidic foods and beverages can give your teeth a chance to recover, especially after whitening treatments.
Sensitivity and Whitening
If you want to whiten but have sensitive teeth, choose products specifically formulated for sensitivity — they typically contain lower peroxide concentrations and added desensitising agents. You can also apply desensitising toothpaste before and after whitening sessions to minimise discomfort. Always consult your dentist before starting a whitening programme if you experience chronic sensitivity.
When to See a Dentist
See a dental professional if sensitivity is sudden and severe, affects a single tooth, doesn't improve with desensitising products, or is accompanied by swelling or pain when biting. These signs could indicate a cavity, fracture, or infection that needs prompt attention.