Sensitive to hot and cold at the same time: what that pattern tells you.
When both hot and cold set a tooth off, the question worth asking is not which one is worse but how long the pain lasts. Sensitivity from exposed dentine is thin and sharp, arrives with the mouthful and leaves with it; pain that begins a moment late and goes on aching after the cup is empty is the pattern a dentist reads as an inflamed nerve inside the tooth, and no toothpaste treats that. Nothing on any shelf stops sensitivity to hot and cold. What a paste can do, when the pain is the short kind, is calm the nerve and narrow the open tubules so that the response fades over weeks. S3 Sensitivity Science™ carries both of those mechanisms in one tube: potassium nitrate for the nerve, nano-hydroxyapatite inside the tubule and biomimetic hydroxyapatite on the surface.
What was checked20 peer-reviewed studies, S3 consumer trial (ADSL, 2026), the Oral Health Foundation and the NHS
- Dentine sensitivity comes with the stimulus and goes with it, and the difference is measurable: how long a tooth kept responding to a clinician's cold test tracked the diagnosis, in the clinical study that put a number on it1.
- No published survey reports how many people with sensitive teeth react to both hot and cold; the trigger surveys record the commonest stimulus, which is cold, and stop there, so this page puts no number on the overlap2.
- Every pooled result for every sensitivity ingredient was gathered against cold air, cold water or touch: the 2026 network meta-analysis of 93 randomised trials lists its outcomes as evaporative cold, tactile and thermal cold, and the Cochrane review of potassium toothpastes recorded thermal responses but published the air-blast and tactile ones34.
- Pain on biting is the sign every page attaches to a cracked tooth, and it is not the commonest one: among teeth with a visible crack, pain to cold was more than twice as frequent5.
- In S3's own consumer trial, run by an outside agency on 51 adults with sensitive teeth over eight weeks and not published, 90% of the panel reported that their teeth felt less sensitive in situations that normally trigger discomfort, after four weeks.
Is there a toothpaste that stops sensitivity to hot and cold?
No, and the honest version of the answer is more useful than the marketed one. A desensitising toothpaste reduces how strongly an exposed tooth answers a stimulus, over weeks of twice-daily use; it does not close the question, and every pooled estimate of how much it reduces the response was measured against cold air, cold water or a probe drawn across the dentine36. The heat half of the promise printed on every sensitivity pack, S3's included, rests on the shared mechanism rather than on a measurement, because no pooled review of desensitising toothpastes reports a result for a hot stimulus34.
So the word "stops" is the reader's, and this page will not borrow it. What the page can do instead is sort the pain, which is the useful work: the toothpaste aisle answers one of the patterns below and none of the other four.
What does it mean when both hot and cold hurt?
Usually that more dentine is uncovered than it was, and both triggers are now reaching the same nerve by the same route. Dentine is threaded with fluid-filled channels running inwards towards the nerve, and once enamel has worn or the gum has drawn back their outer ends are open to the mouth7. Brännström proposed in 1966, in a review of dentine sensitivity, that pain from exposed dentine comes from fluid moving inside those channels and disturbing the nerve endings at their inner end, and that is still the working model8. Cold contracts the fluid and drags it outward quickly; heat expands it and pushes it inward slowly, which is why the Journal's page on why cold hurts your teeth takes the cold half on its own. A tooth that reports the slow trigger as well as the fast one is a tooth with more channels open, or with a nerve that has become ready enough to report a gentle movement.
That is the mechanism, and it is where this page's honesty about numbers starts. Nobody has counted the overlap. The trigger surveys ask what sets the tooth off and publish the winner: in a cross-sectional study of 1,210 dental patients, cold was named by 97.1% of those with hypersensitivity, occasional rather than constant pain was the commonest pattern at 55.5%, and the incisors and the cheek-facing surfaces were the sites most often affected2. What that paper does not report, and what none of the four other trigger-breakdown surveys read for this page reports either, is how many of those people also reacted to heat. Three PubMed searches were run for this page in September 2026, pairing hypersensitivity with prevalence and clinical features, with the phrase hot and cold, and with the words for a breakdown of stimuli; between them they returned two records, neither of them about the overlap. So this page states the gap rather than borrowing a statistic: no published survey counts how many people with sensitive teeth react to both temperatures.
What is counted is where sensitivity sits. In a cross-sectional study of 3,551 adults across seven European countries, funded by Haleon, which makes sensitivity toothpastes, 29.1% had at least one tooth scoring moderate or severe on a clinician's cold-air test, and hypersensitivity was commonest in the lower front teeth and on the cheek-facing surfaces, alongside erosive wear and gum recession at those sites9. Several teeth on one side of the mouth, all reacting to the same drink, is the ordinary shape of the problem. One tooth doing something the others do not is the shape worth taking to a surgery.
How do you tell dentine sensitivity from an inflamed pulp?
By the clock, not by the temperature. Dentine sensitivity is tied to its stimulus: the pain arrives as the cold or the heat arrives, and it stops within seconds of the trigger going away. An inflamed pulp answers late and keeps going, and that difference has been measured. In a clinical study of 60 adults, teeth diagnosed with an inflammation the nerve could still recover from went on responding to a clinician's cold test for about four to five seconds, while teeth diagnosed with the irreversible kind responded for six seconds or more; the longer the response, the higher the level of matrix metalloproteinase-8, an inflammation marker, in the dentine1. The authors offer that as an aid to diagnosis rather than as a rule, and their cold test is a controlled stimulus on an isolated tooth timed by an examiner, not a mouthful of iced water. Even so, it is the closest thing the literature has to the sentence every consumer page writes without a source.
Two more findings make the timing test worth doing properly. The first is that a person cannot be relied on to say which tooth it is. In a clinical study of 64 patients with symptomatic irreversible pulpitis, the healthy tooth next to the inflamed one, and the matching healthy tooth in the opposite jaw, also over-responded to a thermal test, and both settled after the inflamed tooth had been root-treated10. The second is that the words are worth choosing carefully, because they correlate with what the clinic finds: among 228 people presenting with acute toothache, those whose affected tooth still detected cold more often described shooting pain of high intensity, while those whose tooth hurt on percussion described radiating and throbbing pain and rated their overall pain higher11. Take the timing and the adjectives with you; they are data.
A 2019 clinical review written for UK primary dental care puts the three possibilities on this page side by side and says the thing a reader should hear first: a definitive diagnosis of hypersensitivity is difficult, because the same reported symptoms have several possible causes12. The table is the version of that a person can use at the kitchen table. It is not a diagnosis, and the last column says what each row rests on.
| Pattern | When it starts, and how long it lasts | Which temperatures | How many teeth | Other signs | What it usually is | What to do | Evidence for the row |
|---|---|---|---|---|---|---|---|
| Thin, sharp, over quickly | With the stimulus; gone within seconds of it | Cold most often; hot as well when more dentine is uncovered | Often several, often on one side, often cheek-facing | None | Exposed dentine: dentine hypersensitivity | Sensitivity toothpaste twice daily, judged at two to four weeks | Trigger and site surveys29, the second funded by Haleon; pooled toothpaste evidence3 |
| Sharp but heavier, settling within a few seconds | With the stimulus; a few seconds after it | Cold, sometimes hot | Usually one | No pain out of the blue | An irritated nerve that can still recover: reversible pulpitis | Dentist, so the cause is found | Cold-response duration1; the criteria a clinic uses13 |
| Deep, throbbing, hard to place | Starts with or just after the stimulus and outlasts it, often for minutes | Either; heat is often the one that does it | Usually one, but the neighbours may join in | Pain at night, pain with no trigger, painkillers needed | An inflamed nerve that will not settle: symptomatic irreversible pulpitis | Dentist, promptly | Cold-response duration1; spread to neighbouring teeth10 |
| Sharp, often as the bite is released | With biting, or with cold | Cold most often | One | Pain on chewing or on letting go | A cracked tooth | Dentist | Symptom frequencies in cracked teeth5 |
| Variable, often building | With the stimulus | Sweet and cold first, heat as it deepens | One | Food trapping, a mark or a hole, a broken filling | Decay reaching the dentine | Dentist | Clinical convention, not measured; listed as a cause by the Oral Health Foundation7 |
| Dull, diffuse, throbbing | About a quarter of an hour after coming indoors from the cold, lasting up to a few hours | Neither: no pain to hot or cold drinks in the reported cases | Diffuse | Nothing found on a cold test in the clinic | Not dentine sensitivity, and not treated by toothpaste in the reported cases | Dentist, describing the timing exactly | A hypothesis paper on three patients14 |
Row one is where a tube belongs. The rest of this page is about the other five rows, because a page that sells a toothpaste to someone in row three has done them harm.
What if it hurts to bite as well?
Then think about a crack, and think about it early. The received wisdom is that a cracked tooth announces itself on biting, and the largest set of measurements says otherwise. Across 2,858 posterior teeth with a visible crack, in an observational clinical study run through a practice-based research network by 209 practitioners, 45% had any symptom at all; pain to cold was the commonest, in 37% of the teeth, against 16% with pain on biting and 11% with spontaneous pain5. Two thirds of the symptomatic teeth had only one kind of symptom, and most of those hurt only to cold5. The authors say it plainly: pain on biting, although it is treated as the most reliable sign, is not the commonest symptom of a tooth with a visible crack. A cracked tooth can present exactly as sensitivity, which is why the ache that bothers you on chewing deserves a look even if the cold is what brought you to this page.
Cracks are hard for professionals too. In the British Dental Journal, a practice review on cracked teeth describes the condition as commonly encountered in dental practice and as a frequent cause of diagnostic and management difficulty15. That is a fair reason not to try to work it out at the kitchen table. The reason to go early is what the outcome data say. In a retrospective clinical study of 199 cracked teeth judged to have a nerve that could still recover, banded and referred for crowns, 71% were still healthy three years later, while 29.1% went on to an inflamed or a dead nerve; going without a full-coverage crown raised the odds of that happening several times over13. A 2024 systematic review and meta-analysis of 27 studies found cracked teeth keeping a living nerve survived at between 92.8% and 97.8% over one to six years, and that a crack restored without covering the cusps carried roughly three times the risk of nerve complications16. Caught, a cracked tooth is usually kept. That is a better reason to book than fear is.
What can a dentist actually establish?
Less than you would hope, and enough to act on. The tests a dentist runs on a nerve are a cold stimulus, a heat stimulus, a small electric current and, in some practices, a device that reads blood flow, and two meta-analyses have pooled how well they perform. The larger of the two, a meta-analysis of 28 studies, put the cold test at a sensitivity of 0.87 and a specificity of 0.84, the electric test at 0.72 and 0.93, and the heat test last of the five at 0.78 and 0.6717. The second, of ten studies, is harsher: it puts the pooled diagnostic odds ratio at 17.24 for the cold test and 3.47 for the heat test, with the cold test's sensitivity at 79% and the heat test's at 54%, and it recommends against using either as the only test18. The two do not agree about how bad the heat test is, and the second review rests on two studies for that estimate and rated none of its included studies good on quality, so the disagreement is printed here rather than averaged1817.
Two things follow. The first is that no single test settles it, which is why a dentist will use several, ask about the timing, tap the tooth, check the bite and take a radiograph. The second is that these tests answer a narrower question than the one you arrived with: they establish whether a nerve is alive, not whether it is inflamed and not whether your dentine is sensitive17. The diagnosis comes from the history as much as from the instruments, which is the practical reason to turn up with your timings.
If the answer is the nerve, the treatment is usually root canal treatment. The NHS describes it as removing the soft tissue from inside the tooth, cleaning and filling it, generally over two or more appointments under local anaesthetic, with a crown afterwards if the tooth was badly infected19. It is worth knowing that before the appointment, because the thing people fear at this point is losing the tooth, and losing the tooth is the alternative to treating it rather than the consequence of it19.
Which ingredients have evidence, and against which stimulus?
The two that matter for a tooth reacting to both temperatures do different jobs, and the evidence for each is stimulus-specific. In the 2026 network meta-analysis of 93 randomised trials and 9,548 participants, measured at two weeks against a benchmark fluoride toothpaste, nano-hydroxyapatite showed a large reduction on the cold-air score with moderate confidence from two studies, stannous fluoride a similar reduction rated high confidence from ten, arginine from seven at low confidence, and potassium with or without fluoride a small but important effect from one study at low confidence3. The 2020 network meta-analysis of 125 randomised trials and 12,541 patients had already put potassium combined with hydroxyapatite among the formulations with a large effect against both an air stimulus and a tactile one6. A 2019 systematic review and meta-analysis of six four-week randomised trials found nano-hydroxyapatite ahead of its comparators on evaporative and tactile stimuli and no different on cold liquids, which is a real limit and belongs on a page about temperature20.
Potassium is the older ingredient and the one with the most equivocal review. Its six randomised trials, pooled by Cochrane in 2006, put potassium nitrate ahead of control toothpastes on the air-blast and tactile measures at six to eight weeks; the same review found nothing significant when it looked at what the patients themselves said, and its authors ended by calling the case for potassium toothpastes unproven4. An industry-funded double-blind randomised trial of 120 adults, paid for by a company that makes a competing stannous fluoride paste, tracked a marketed potassium nitrate toothpaste against a plain fluoride control and found its advantage on the cold-air score growing from day three to week eight rather than fading21. And a 2017 UK guideline review for general dental practice says the thing a shopper should carry into the aisle with them, which is that the profession still has no single agent it can hold up as the ideal one22.
Read the two paragraphs together and the picture for this page is consistent. Occlusion and nerve-calming are answers to different halves of the same tooth, the evidence for both was collected against cold and touch, and the timescale is weeks. The sibling pages take the halves further: one on hot drinks and coffee for the physics of heat and why the trials leave it out, one on cold drinks and ice cream for the cold-liquid exception in that meta-analysis, and the trigger-to-ingredient map for the shopping version of the question.
Where does S3 sit if both hot and cold hurt?
On the first row of the table, and nowhere else on it. S3 was formulated for the two things that row describes at once: a nerve that fires too readily and dentine tubules that are open, with potassium nitrate for the first and two forms of hydroxyapatite for the second. It is a daily toothpaste rather than a fortnight's treatment, which is the honest way to describe something whose actives accumulate: the potassium builds around the nerve and the mineral is laid down brush by brush, so S3 starts working from the first brush and is judged at two to four weeks.
Three claims this page does not make, and this is the place to say why. The trial evidence behind S3's actives, like everyone else's, was gathered against cold and touch, so the hot half rests on the shared mechanism3. Its own numbers come from a consumer trial rather than a clinical one: an outside agency, 51 adults with sensitive teeth, eight weeks, self-reported answers, and no publication to check, which is why the figure in the key points is written as what the panel said rather than as a result. And the percentages on the tube are inclusion levels: 10% nano-hydroxyapatite and 5% biomimetic hydroxyapatite as supplied, with a lower active content, and S3 states both.
The sentence that matters most on this page is the one that costs a toothpaste company a sale. If both temperatures hurt one tooth, and the ache lingers after the drink, a sensitivity toothpaste is the wrong purchase, and a delay: it may dull the signal that would otherwise have got you an appointment.
When should you stop reading and book an appointment?
When any one of a short list is true. The Oral Health Foundation supplies most of it: severe pain, sensitivity that has now run on for more than a few weeks, a single affected tooth, or a sudden start, because behind any of those can sit decay, a crack, a gum problem or an infection7. This page adds the item it has spent its length on, which is pain that outlasts its trigger, together with pain that wakes you, pain arriving with no trigger at all, and pain on biting. Any of them makes the appointment the whole of the answer, and the tube a question for afterwards.
The NHS gives toothache a deadline of two days, and shortens it when painkillers are not working, when a temperature has arrived with the pain, when biting hurts, when the gums are red or the mouth tastes bad, or when a cheek or a jaw has swollen; the person to call, it says, is a dentist and not a GP23. Its holding advice while you wait is to avoid anything very hot, very cold or sweet, which for this reader means both ends of the range go on hold until somebody has looked23. The Journal's page on why are my teeth suddenly sensitive sets out the general version of that list; this page's contribution is the clock.
Frequently asked questions
Is there a toothpaste that stops sensitivity to hot and cold?
No. A desensitising toothpaste lowers how strongly an exposed tooth answers a stimulus, over weeks of twice-daily use, and the pooled evidence for that was collected against cold air, cold water and a probe, never against a hot drink34. If the pain is thin, sharp and over when the mouthful is over, a paste that calms the nerve and narrows the tubules is a sensible daily step and should be judged at two to four weeks. If the pain lingers, no tube on the shelf is the answer to it.
Does being sensitive to hot and cold mean the nerve is dying?
Not on its own. Reacting to both temperatures most often means more dentine is uncovered, so the slower trigger now registers as well as the faster one7. What points at the nerve is duration rather than temperature: a response that keeps going for six seconds or more after a clinician's cold test went with a diagnosis of irreversible inflammation in a clinical study of 60 adults, while four to five seconds went with the recoverable kind1. At home the equivalent question is simpler. Does the pain stop when the drink is finished, or is it still there a minute later?
Why does my tooth hurt after the drink rather than during it?
Because a delayed pain is coming from a different place. Dentine sensitivity is a fluid-movement pain and it tracks the stimulus almost exactly; an inflamed nerve produces a deeper, throbbing pain that starts late and outlasts what caused it, and it can be hard to say which tooth it belongs to, because the healthy neighbours of an inflamed tooth over-respond too10. Describe the delay and the duration when you book, and use your own words for the pain, since the words people choose line up with what the clinical tests find11.
Can a sensitivity toothpaste such as S3 hide a problem?
It can mask a symptom, and that is a real risk worth naming. A desensitising paste works on exposed dentine; it does nothing to decay, a crack, an infection or an inflamed nerve, and reducing the twinge from the sound teeth around a bad one can make the picture harder to read. So the rule is the timing test first and the tube second. If the pain is short and stimulus-bound, start the paste and give it two to four weeks. If it lingers, spreads, wakes you or comes with pain on biting, book the appointment, and do not let four comfortable weeks talk you out of it.
How long should I wait before seeing a dentist?
For toothache with nothing else to it, the NHS answer is two days, brought forward by any of its red flags: painkillers that do not work, a temperature, pain on biting, red gums, a bad taste, a swollen face23. For sensitivity that behaves itself, the Oral Health Foundation's threshold is a few weeks without improvement, along with severe pain, a single affected tooth or a sudden onset7. There is no waiting period at all for pain that outlasts its trigger or arrives without one.
Where S3 sits
Both temperatures reach the same nerve through the same open channel, so the two things worth changing are the channel and the nerve: hydroxyapatite narrows the one, potassium quietens the other, and neither does the other's job. That makes a paste carrying both a reasonable daily step for the short, sharp kind of pain, judged at two to four weeks rather than over a weekend, and it is a step and not a stop. It is not an answer to an ache that lingers, and this page would rather lose the sale than blur the difference.
S3 Sensitivity Science™ pairs potassium nitrate with two hydroxyapatites and adult-strength fluoride in one daily paste.
See the toothpastePotassium nitrate at 5% for the nerve, nano-hydroxyapatite at 10% and biomimetic hydroxyapatite at 5%, both as solution, for the tubule and the surface, and fluoride at full adult strength, all in one daily toothpaste. Calm, strengthen, protect: the three actions sensitive teeth need, from one tube. The blend is filed as S3 Repair Technology™, patent-pending under UK application GB2604755.5. More than 20 practising UK dentists own a stake in S3, and nine founding dentists advise on the formulation. Read more about S3.