What Causes Tooth Sensitivity? Common Triggers and What May Help

If a sip of cold water sends a sharp pain through your teeth, you’re probably wondering what causes tooth sensitivity. The twinge fades quickly, but it makes you think twice about your next mouthful. You might also feel it while brushing your teeth or breathing in cold air on a winter morning.

These moments are easy to brush off, but they usually mean something has changed. Caring for sensitive teeth and gums starts with understanding what’s behind that change.

 

Quick Overview

• Tooth sensitivity is a brief, sharp pain that occurs when heat, cold, sweetness or touch reaches a part of the tooth that is normally covered.
• It’s one of the most common dental complaints, and it may affect one tooth or several.
• It’s often linked to enamel wear or receding gums, though in some cases it signals decay or a crack.
• What sets the pain off and how long it lingers vary, and these details usually guide the next steps.

Below, we explain why teeth become sensitive, what triggers it and which habits may help.

 

Why Do Teeth Become Sensitive?

Teeth become sensitive when the tooth’s protective barrier wears thin or pulls back. Enamel covers the crown, and the gums cover the tooth roots. When either is lost, the dentine underneath is exposed, and everyday triggers can reach the nerve.

Enamel is the hard outer layer of the tooth. Dentine contains tiny channels that lead towards the nerve. When cold foods, sweet foods or toothbrush bristles touch exposed dentine, fluid in these channels is thought to shift, and the nerve reads that movement as pain. That’s why tooth sensitivity feels so sudden.

 

What Causes Tooth Sensitivity Most Often?

Common causes include enamel erosion, gum recession, aggressive brushing and teeth grinding. More than one can be at work at once.

• Acidic foods and drinks. Soft drinks, citrus fruits, juices and wine can soften enamel. Sipping acidic drinks or consuming acidic foods between meals keeps acid on your teeth for longer.
• Aggressive brushing. Scrubbing hard can wear the tooth surface and contribute to gums pulling back.
• Gum recession and gum disease. Receding gums leave exposed roots, which have no enamel covering them. Gum disease, also called periodontal disease, is one reason gums pull back.
• Teeth grinding. Clenching or grinding, often during sleep, can wear down enamel over time.

Can Tooth Decay or Cracked Teeth Cause Sensitivity?

Yes. Tooth decay, cracked teeth and fillings that are breaking down can all cause pain that feels like sensitivity. Pain that lingers after the cold or sweet trigger has gone may be a sign of decay rather than enamel wear.

These need a different approach from everyday sensitivity, so ruling them out comes first. Sudden tooth sensitivity is worth having checked for this reason. Desensitising toothpaste won’t help when decay is causing sensitivity, because the tooth will usually need a filling.

 

Why Do Teeth Feel Sensitive After Dental Procedures?

Fillings and gum treatments can leave teeth feeling sensitive for a while. This temporary sensitivity may last up to two weeks.

If the mild discomfort grows stronger or doesn’t ease, it’s worth having the tooth checked again.

Everyday Habits That May Reduce Sensitivity

Small changes at home may help alleviate sensitivity over time.

• Brush gently. Use a soft-bristled toothbrush and a gentle technique rather than a hard back-and-forth scrub.
• Time your brushing. Don’t brush immediately after acidic meals. Wait at least 30 minutes so saliva can neutralise the acid.
• Keep good oral hygiene. Brushing twice daily with fluoride toothpaste and flossing every day may help strengthen enamel and keep your gums healthy.
• Try a desensitising toothpaste. These calm the nerve’s response or form a barrier over exposed dentine.
• Rethink your drinks. Choose tap water over soft drinks, and keep acidic foods and drinks to mealtimes.

 

How Your Dentist Works Out What Causes Tooth Sensitivity

Finding what causes sensitive teeth matters more than masking the pain. During a dental visit, your dentist may ask what seems to trigger pain, along with your eating, drinking and brushing habits. They may also check for decay, cracks or worn fillings and use a gentle puff of air to test individual teeth.

Treatment options may include a fluoride gel or varnish, a filling to cover worn areas or repair decay, or a custom-made splint for grinding. In some cases of gum recession, a gum graft may be discussed. The right tooth sensitivity treatment depends on your individual situation, and outcomes vary. Even mild sensitivity is worth mentioning, as it often goes unreported.

When Sensitive Teeth Need a Closer Look

It’s tempting to ignore sensitivity when it comes and goes, especially if cold temperatures are the only trigger. The same twinge can come from worn enamel, a receding gumline or early decay, so knowing the cause matters. At Maroondah Dental Care, our dentists use digital X-rays and intraoral cameras to examine your teeth and gums closely, so we can show you what’s behind the discomfort. If persistent sensitivity is affecting your oral health or your enjoyment of food, please call us on 03 9007 2532 to arrange a visit to our dental clinic.

 

Frequently Asked Questions

Can teeth whitening make my teeth sensitive?

Yes, sensitivity can follow whitening treatment, and it’s usually temporary. Highly abrasive whitening toothpastes may also make existing sensitivity worse. If your teeth are already sensitive, it’s worth discussing this before whitening.

Can acid reflux make my teeth sensitive?

It can. Acid from reflux or frequent vomiting can wear away enamel, which may leave teeth sensitive to heat and cold. Rinsing your mouth with water or milk afterwards may help reduce the acid’s contact with your teeth.

Can children get sensitive teeth?

Yes. A child’s teeth may be sensitive if the enamel didn’t form properly during development, a condition called enamel hypoplasia. Baby teeth also have softer enamel that acids can damage more easily. Sensitivity can also be an early sign of decay.

Can worn enamel grow back?

No. Once enamel is lost, the body can’t replace it. Saliva and fluoride can help repair the earliest stages of acid softening and strengthen tooth enamel that remains. Surfaces already worn away may need a filling.

Should I keep using sensitive toothpaste once my teeth feel better?

Continuing to use it is generally advised, because sensitivity may return if you stop. You can also dab a small amount directly onto a sensitive spot with your fingertip before brushing.

 

References

Australian Dental Association. Sensitive teeth. https://teeth.org.au/sensitive-teeth

Better Health Channel, Victorian Department of Health. Dental erosion. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/dental-erosion

Healthdirect Australia. Dental erosion. https://www.healthdirect.gov.au/conditions/mouth-and-tooth-diseases/dental-erosion

Cleveland Clinic. Enamel hypoplasia. https://my.clevelandclinic.org/health/diseases/enamel-hypoplasia

Cekici A, Shaikh A, Alsayed A, et al. Evidence-based recommendations for diagnosing and managing dentine hypersensitivity in clinical practice: insights from the Middle East and Africa. Frontiers in Oral Health. 2025;6:1663984. https://www.frontiersin.org/journals/oral-health/articles/10.3389/froh.2025.1663984/full