Sensitive Teeth: Causes, Fixes, and When to See a Dentist
Written by NoFrills Dental clinical team
Updated 12/08/2026
Tooth sensitivity is a short sharp pain from exposed dentine, and the single most useful thing you can measure is how long it lasts: a second or two is ordinary sensitivity, thirty seconds or more is a warning sign. Here is what causes it, which treatments the evidence actually supports, and the point at which it stops being something a toothpaste can fix.
- Caused by exposed dentine, not by weak teeth.
- The most common routes to it are acid wear and gum recession.
- Desensitising toothpaste needs six to eight weeks, used twice daily.
- Pain that lingers, arrives unprovoked or wakes you needs a dentist, not a toothpaste.
What tooth sensitivity actually is
Under the enamel sits dentine, and dentine is not solid. It is threaded with microscopic tubules filled with fluid, and those tubules run inward toward the nerve. The explanation clinicians work from is the hydrodynamic theory, first proposed by Martin Brannstrom in 1966: when something cold, hot, sweet or acidic reaches exposed dentine, the fluid inside those tubules moves, and that movement is what the nerve registers as a sudden sharp pain.
Two conditions have to be met, which is why not everyone with worn teeth gets it. The dentine has to be exposed, and the tubules have to be open at both the surface and the pulp end. That is also why treatment works the way it does: almost everything either plugs the tubules or calms the nerve.
Singapore's HealthHub, using content from the Singapore Dental Health Foundation, puts it in plainer terms: eating or drinking something hot, cold or sweet changes the fluid movement, the nerve endings react, and you get a short sharp pain.
How common is it?
More common than the figures suggest, and harder to pin down than you would expect. The American Dental Association, citing a 2019 review in the Journal of Dentistry, puts dentine hypersensitivity at about 11.5 per cent of patients. But the same body of research reports a global range from 1.3 per cent to 92.1 per cent depending on how it is measured, with an average across all studies of around 33 per cent, and roughly 38 per cent across Asian studies.
That spread is not sloppiness. Ask people whether their teeth feel sensitive and you get one number. Blow a calibrated puff of air on each tooth and examine them properly and you get a much higher one: in a seven-country European study of 3,551 adults published in 2024, 75.9 per cent had measurable sensitivity on examination.
For Singapore specifically there is no published prevalence study we could find. HealthHub states that tooth sensitivity can affect more than half the population, which is worth reading as a clinical impression from a national health portal rather than a measured Singaporean figure. We would rather tell you that than dress it up.
What causes sensitive teeth
Sensitivity is a symptom with several routes to it, and they often stack. The two that dominate are acid wear and gum recession.
| Cause | What it does |
|---|---|
| Dietary acid | Softens and thins enamel, then opens the tubules underneath. Carbonated drinks including diet versions, juices, citrus, sour sweets and vinegar-based food are the usual sources. |
| Gum recession | Uncovers root surface, which has no enamel over it at all. Present in 87.9 per cent of adults in one large European study, and significantly linked to sensitivity. |
| Hard brushing | Abrasion wears the surface and contributes to recession. The effect compounds if you brush shortly after something acidic. |
| A cracked tooth | Produces erratic pain on chewing, classically as you release the bite. It will not heal on its own. |
| Recent dental treatment | Common and usually temporary. After gum treatment, root sensitivity affects 54 to 55 per cent of patients, peaking one to three weeks later, then settling. |
| Grinding and clenching | Loads the teeth in ways they are not built for and accelerates wear at the neck of the tooth. |
| Acid reflux | Brings stomach acid to the teeth, often overnight. Sensitivity is significantly associated with heartburn. |
| Whitening | Post-treatment sensitivity is well recognised and usually temporary. |
Prevalence and association figures: West and colleagues, Journal of Dentistry, 2024; tooth wear guidance: FDI World Dental Federation policy statement on tooth wear, 2023.
Worth knowing, because it runs against instinct: in that same 2024 study, people using powered toothbrushes had significantly less sensitivity, less erosive wear and less bleeding on probing than manual brushers. The brush is not the enemy. The pressure is.
If your gums have receded or bleed when you brush, the sensitivity is a symptom of something else and treating it alone will not hold. That is gum disease territory, and it is worth reading our notes on what your gums are telling you.
When it is not just sensitivity
This is the part worth committing to memory, because ordinary sensitivity and a dying nerve feel similar for the first second and then diverge completely. The American Association of Endodontists sets out the distinction by duration and trigger.
Sharp, provoked by cold, sweet or acid, and gone almost as soon as the trigger is removed. Never spontaneous. Manage it at home first.
Pain that lingers well after the trigger, arrives with no trigger at all, worsens lying down or bending over, or shrugs off ordinary painkillers. Also any pain on biting. This is the pattern of irreversible pulpitis.
Swelling around the eye or neck, or swelling in the mouth or neck making it hard to breathe, swallow or speak. Also swelling with fever. Do not wait for a dental appointment.
Duration thresholds are the American Association of Endodontists diagnostic criteria. The A and E thresholds are the NHS toothache guidance, which is the clearest plain-language version of advice that is the same in Singapore. If you are unsure which column you are in, our page on emergency and walk-in dental care sets out what we can treat the same day.
One more pattern that does not fit neatly in a box: a tooth that hurts sharply when you bite and release, but tests normally to cold, is behaving like a cracked tooth. Cracks are frequently missed because the pain comes and goes and the tooth can look intact. Say so explicitly when you book.
Do desensitising toothpastes work?
Mostly yes, and the honest answer is more interesting than the packaging.
The largest synthesis available is a 2020 network meta-analysis in the Journal of Dental Research pooling 125 randomised trials and 12,541 patients. It found calcium sodium phosphosilicate the most beneficial across all three test stimuli with high to moderate certainty, with stannous fluoride, potassium combined with stannous fluoride, and arginine also showing real benefit. The American Dental Association's current position matches: stannous, potassium with or without stannous, or arginine can be recommended, applied twice daily.
Measured benefit against an air stimulus
Standardised mean difference versus a fluoride control. Journal of Dental Research network meta-analysis, 2020, 125 trials and 12,541 patients.
Bars are scaled to the largest effect in this comparison, not to an absolute scale. A larger standardised mean difference means a bigger measured reduction in pain against that specific stimulus, and the ranking changes depending on whether the test uses air, cold or touch.
The nuance the box will not tell you concerns potassium nitrate, the most common desensitising ingredient on Singapore shelves. The Cochrane review of potassium toothpastes found a statistically significant effect on air-blast and tactile testing at six to eight weeks, but no significant effect on what patients themselves reported, and concluded that no clear evidence is available to support them. That review is from 2006 and has not been updated. The 2020 network analysis, which is larger and more recent, does find a benefit for potassium. Both things are true, and the sensible reading is that potassium helps somewhat, less reliably than stannous fluoride or arginine, and not as dramatically as the advertising implies.
How long before it works
Clinical evidence, not manufacturer claims.
Use it twice a day like ordinary toothpaste. Rubbing a little directly onto the sensitive area with a fingertip before brushing is a recognised way to get more out of it.
If a month of desensitising toothpaste has not shifted it, the cause is worth finding.
What a dentist can do
The clinical ladder runs from least to most invasive, and a good appointment starts by working out which rung you belong on rather than jumping to the top.
- Find the actual cause. Sensitivity is the presenting symptom for cracked teeth, decay, leaking old fillings, gum recession and a dying nerve, and the treatment for each is different. A full examination with x-rays where they will change the decision is the only way to separate them.
- Treat what is underneath. If it is decay it needs a filling. If it is gum disease it needs scaling or gum treatment. If the nerve is dying it needs root canal treatment, and a heavily broken-down tooth may need a crown afterwards.
- Seal the exposed surface. In-office desensitisers and fluoride varnish are applied directly to the sensitive area. The evidence here is clinical experience rather than large trials, and we would rather say so, but they are quick, cheap and low risk.
- Rebuild or cover, if needed. A worn notch at the neck of the tooth can be bonded. Where recession is severe and there is an aesthetic concern too, gum grafting is an option, though the consensus positions it as aesthetics-led rather than a sensitivity treatment.
- Protect it from what caused it. If you grind, a night guard changes the loading. Our page on grinding and clenching covers what that involves. You can book at Suntec City, Marina Square, Marine Parade or Tanjong Katong.
On cost: a consultation and examination is $50 and a scale and polish is $80 to $120 on our published price list, before GST. If you hold a card, CHAS, Merdeka and Pioneer Generation subsidies come off at the counter, and our guide to CHAS dental subsidies in 2026 sets out the current rates. MediSave does not apply to any of this, because it covers surgical procedures only.
What to change at home
Four changes carry most of the benefit, and none of them cost anything.
- Wait before you brush. Acid softens enamel for a while after you eat or drink. Brushing inside that window scrubs away softened surface. Give it 30 to 60 minutes.
- Change how you drink, not what you drink. Acidic drinks with a meal rather than sipped across an afternoon, water afterwards, and do not swish it around your teeth. Frequency does more damage than volume.
- Brush softer, not harder. Soft bristles, low abrasion paste, light pressure. A powered brush with a pressure sensor takes the decision out of your hands.
- Keep the gums healthy. Recession is the other main route to exposed dentine, and it is largely preventable. Our notes on daily oral hygiene, flossing and preventing tartar cover the practical side, and smoking works against all of it.
If reflux or heartburn is part of your life, mention it. Sensitivity is significantly associated with heartburn, and the acid arriving from the inside will keep undoing the work until it is addressed. The same goes for whitening and cosmetic treatment: tell whoever is planning it that your teeth are sensitive, because the approach can be adapted.
Sensitive teeth that have not settled?
We will find out why before treating it. Four clinics in Singapore, at Suntec City, Marina Square, Marine Parade and Tanjong Katong, all beside an MRT station.
Frequently asked questions
What is tooth sensitivity?
Tooth sensitivity, known clinically as dentine hypersensitivity, is a short sharp pain that comes from exposed dentine when something cold, hot, sweet or acidic touches the tooth. Dentine contains microscopic fluid-filled tubules that connect to the nerve. When the surface is worn or the gum has receded, those tubules open and fluid movement inside them triggers the nerve. The pain is brief and it stops when the trigger is removed.
How long does desensitising toothpaste take to work?
Longer than most people give it. The Cochrane review measured its effect at six to eight weeks, and clinical guidance suggests some formulations show benefit from around three days to four weeks. Use it twice daily and give it at least a month before deciding it has failed. If symptoms settle, keep using it, because stopping can let the tubules gradually reopen.
Which desensitising ingredient is the most effective?
A 2020 network meta-analysis in the Journal of Dental Research, pooling 125 randomised trials and 12,541 patients, found calcium sodium phosphosilicate the most beneficial across all three test stimuli, with stannous fluoride, potassium combined with stannous fluoride, and arginine also showing benefit with high to moderate certainty. The American Dental Association currently says stannous, potassium with or without stannous, or arginine can be recommended.
When is sensitivity a sign of something worse?
The useful test is how long the pain lasts. Normal sensitivity stops within a second or two of removing the trigger. The American Association of Endodontists describes pain that lingers 30 seconds or longer, arrives spontaneously without a trigger, worsens when you lie down or bend over, or does not respond to ordinary painkillers as the pattern of irreversible pulpitis, which usually needs root canal treatment. Pain on biting, or swelling with fever, needs to be seen quickly.
Can whitening cause sensitive teeth?
Post-treatment sensitivity after bleaching is well recognised, and it is one of the conditions clinicians are told to rule out before diagnosing ordinary dentine hypersensitivity. We are not aware of a reliable published figure for how often it happens, so we would rather not quote one. It is usually temporary. Tell your dentist if you have had sensitivity before, because the approach can be adjusted.
Does brushing harder help clean sensitive teeth better?
No, and it tends to make things worse. Brushing hard with an abrasive paste wears the surface and can contribute to gum recession, which exposes more dentine. The FDI World Dental Federation recommends a non-aggressive technique with a low abrasive toothpaste. In a study of 3,551 European adults, powered toothbrush users had significantly less sensitivity, less erosive wear and less bleeding gums than manual brushers.
Should I stop eating acidic food?
You do not have to give it up, but timing matters. Acids soften enamel temporarily, so brushing straight after an acidic drink scrubs the softened surface away. Clinical guidance suggests waiting 30 to 60 minutes before brushing, drinking acidic drinks with a meal rather than sipping them across an afternoon, and rinsing with water afterwards.
Related reading
Sources: American Dental Association, Oral Health Topics: Toothpastes; Martins and colleagues, Journal of Dental Research, 2020; Cochrane review of potassium containing toothpastes; American Association of Endodontists, Endodontic Diagnosis; NHS, Toothache; HealthHub, Tooth Sensitivity.
