Quick answer
Tooth sensitivity usually happens when the protective enamel or gum tissue wears away and exposes dentin, the layer underneath that leads to the nerve. Common causes include brushing too hard, gum recession, grinding and acidic foods. A desensitizing toothpaste with potassium nitrate or stannous fluoride often helps, but lingering pain should be checked by a dentist.
That sudden sharp twinge when you sip something cold can stop you mid-sentence. Sensitivity is one of the most common things patients mention at checkups, and in many cases it’s very manageable once you know the cause.
What causes sensitive teeth?
Your teeth are covered by enamel above the gumline and by cementum below it. Underneath is dentin, which contains thousands of tiny tubes that connect to the nerve. When dentin is exposed, hot, cold, sweet or acidic things can reach the nerve and trigger that sharp feeling.
Dentin can become exposed when:
- You brush too hard or use a hard-bristled toothbrush, wearing down enamel and gums
- Your gums recede, often from gum disease or aggressive brushing
- You grind or clench your teeth, especially at night
- Acidic foods and drinks like soda, citrus and sports drinks soften enamel over time
- You have a cavity, crack or worn filling
- You recently had whitening or dental work, which can cause temporary sensitivity
What helps at home?
- Switch to a desensitizing toothpaste. Look for potassium nitrate, which calms the nerve, or stannous fluoride, which helps block the tiny tubes in dentin. Use it twice daily for a few weeks; the effect builds over time.
- Use a soft-bristled brush and gentle, short strokes.
- Cut back on acidic drinks, use a straw, and rinse with water afterward.
- Wait a little before brushing after acidic foods to let your enamel recover.
When sensitivity is a sign of something more
Sensitivity that lingers long after the cold or hot thing is gone, pain when you bite, or sensitivity in just one tooth can point to a cavity, a crack or an inflamed nerve. These need a professional look, and sometimes a filling or root canal.
How dentists treat sensitivity
Depending on the cause, your dentist may apply a fluoride varnish or desensitizing agent, bond a protective coating over exposed root surfaces, replace a worn filling, or recommend a night guard if grinding is part of the problem.
Key takeaways
- Sensitivity usually means exposed dentin.
- Desensitizing toothpaste works best when used consistently for several weeks.
- A soft brush and fewer acidic drinks protect enamel.
- Sensitivity in one tooth or pain on biting needs an exam.
Frequently asked questions
How long does it take sensitive toothpaste to work?
Many people notice improvement within two to four weeks of twice-daily use. Keep using it to maintain the effect.
Is tooth sensitivity permanent?
Not always. Sensitivity from whitening or a new filling is often temporary. Sensitivity from gum recession or worn enamel can be managed with the right toothpaste and treatment.
Can sensitive teeth be a sign of a cavity?
Yes. If one tooth is sensitive or it hurts to bite, a cavity or crack could be the cause. Book an exam to find out.
Need a dentist in Charlotte?
Cusp Dental Group welcomes new patients at three offices: SouthPark, Blakeney and Steelecroft. Same-day emergency appointments are available.
Sources: Colgate: Potassium nitrate and tooth sensitivity · ADA Seal of Acceptance product information
This article is for general education and isn’t a substitute for a personal dental exam or professional advice. If you have pain, swelling or a dental injury, contact a dentist promptly.
