Emergency dental symptoms
Tooth sensitivity: when hot and cold pain is normal and when it is not
Most sensitive teeth are a nuisance rather than an emergency. But a tooth that keeps hurting after the cold has gone is a different problem, and the difference is measured in seconds.
Clinically reviewed by Dr Ibraheem Ijaz, Principal Dentist · GDC 301711 · Last reviewed April 2026
Why teeth feel hot and cold
Enamel has no nerves in it at all. The layer beneath, dentine, is full of microscopic tubes filled with fluid, each one running from the surface to the nerve in the middle of the tooth. When something cold touches open dentine, the fluid in those tubes contracts and shifts, and the nerve endings at the far end read that movement as a sharp jolt. Enamel and gum normally cap the tubes. Lose either, and cold water, cold air or a spoonful of ice cream reaches them directly. That is ordinary sensitivity: sharp, short, and gone the moment the cold is.
The other kind of sensitivity comes from the nerve itself. When the pulp is inflamed by decay, a crack or a deep filling, it over-reacts, and the pain carries on long after the trigger has gone. The causes, most to least common:
Gum recession.
Worn enamel.
Decay or a leaking filling.
A cracked tooth.
Recent dental work.
Pulpitis.
Sensitivity that is normal and sensitivity that is not
Here is the test we use, and you can do it at home. Sip cold water, hold it on the tooth, swallow, and count. Pain that stops within a few seconds is open dentine, and the nerve is healthy. Pain that is still there at ten seconds, or thirty, or builds into an ache, means the nerve is inflamed and probably past recovery. Pain from hot drinks that is relieved by cold is the most telling of all. Some patients arrive at the practice clutching a bottle of iced water because it is the only thing that helps; that is irreversible pulpitis until proved otherwise. So is a tooth that hurts with no trigger, or wakes you up.
When sensitivity is an emergency
A routine appointment.
Call today.
A&E.
What helps at home tonight
- 01Use a sensitive toothpaste (one containing potassium nitrate or stannous fluoride) twice a day, and rub a little onto the worst tooth at bedtime and leave it there without rinsing. It works by plugging the open tubes and calming the nerve endings, and takes around two weeks of regular use to make a real difference.
- 02Switch to a soft brush and brush gently in small circles rather than scrubbing across the gum line.
- 03Wait 30 to 60 minutes after anything acidic before brushing. Enamel is softened by acid and brushing it straight away wears it off.
- 04Cut down on fizzy drinks and fruit juice, or drink them through a straw. Skip whitening products until the cause is known.
- 05Paracetamol or ibuprofen as directed on the packet if a tooth is aching rather than twinging.
How we find the cause of sensitivity
At the emergency examination (£30 including X-rays, about 15 minutes) we start by asking you to point, then look for recession, worn notches at the gum line, cracks, decay and the edges of old fillings. A puff of air from the syringe across each tooth finds open dentine: sharp pain that stops instantly. A cold test with a soaked cotton pellet, timed with the seconds counted, separates a healthy nerve from an inflamed one. We tap each tooth to check the ligament, use a bite test if a crack is possible, and take a digital X-ray to look for decay under fillings and any infection at the root tip. Ten minutes of tests tell us whether this is a toothpaste problem or a nerve problem.
Treatment options from toothpaste to root canal
- Exposed dentine. A fluoride varnish painted onto the sensitive surfaces, which seals the tubes and can be repeated. For deeper notches or exposed roots, a thin layer of bonded white filling over the area (£150–£220). A night guard if grinding is wearing the teeth, and a hygienist visit if gum disease is behind the recession; see our hygiene and gum health page.
- Decay or a leaking filling. The old filling and decay are removed and the tooth refilled, white (£150–£220) or silver (£120–£160), usually in the same visit.
- A cracked tooth. A crown to hold the tooth together (£750–£1,000).
- Irreversible pulpitis. The inflamed nerve is removed. Stage 1 of an emergency root canal (from £200) takes the pain away that day; the treatment is completed at a second visit (from £450). Nik, our associate dentist with a postgraduate certificate in endodontics, does these under a dental microscope. Extraction (£120–£260) is the alternative. Our root canal page explains the process.
Fees are agreed in writing before treatment. Evening and weekend emergency visits carry an additional out-of-hours charge.
| Treatment | Fee (from) |
|---|---|
| Emergency examination including X-rays | £30 |
| New patient examination including X-rays | £85 |
| White filling or bonded root cover | £150–£220 |
| Emergency root canal stage 1 | £200 |
| Completed root canal treatment | £450 |
| All-ceramic crown | £750–£1,000 |
What happens if you put up with it
Dentine sensitivity is not dangerous, but exposed dentine decays faster than enamel and wears into deeper notches, and people naturally stop brushing the bit that hurts, which brings decay and gum disease to exactly the wrong place. Nerve sensitivity follows a fixed path: a nerve that could have recovered becomes one that cannot, and then one that dies. A tooth whose sensitivity suddenly vanishes has not cured itself; the nerve has stopped working, and an abscess usually follows a few months later. What would have been a filling becomes a root canal, and what would have been a root canal becomes an extraction.
Questions, answered
Common questions
Can tooth sensitivity go away on its own?
Sensitivity after whitening, a new filling or gum treatment usually fades within days to weeks. Sensitivity from recession or worn enamel improves with sensitive toothpaste but the cause stays. Lingering pain from one tooth does not go away, because the nerve is inflamed.
Why is only one tooth sensitive?
Recession and enamel wear affect several teeth at once, so a single sensitive tooth usually has its own problem: decay, a leaking filling, a crack or an inflamed nerve. That is the one worth having looked at soon.
Does sensitivity mean I need a filling?
Not usually. Most sensitivity is open dentine at the gum line and is treated with toothpaste, varnish or a thin bonded cover. A filling is needed when decay or a leaking old filling is the cause.
How long does sensitive toothpaste take to work?
About two weeks of twice-daily use, and it keeps working only while you keep using it. Rubbing a little onto the sensitive tooth at night and leaving it without rinsing speeds it up.
Why does my tooth hurt with hot drinks but feel better with cold?
That pattern means the nerve inside the tooth is inflamed beyond recovery and gas is building up in the pulp; cold shrinks it and eases the pressure. The tooth needs a root canal or an extraction, and painkillers will only hold it for so long.
Is tooth sensitivity a dental emergency?
Brief cold sensitivity across several teeth is not. One tooth with pain that lingers, hurts with hot, or wakes you is, because the nerve is inflamed and the sooner it is treated the more likely the tooth is kept. We see those the same day for £30.
In pain? Don’t wait
Same-day emergency appointments, seven days a week.
£30 emergency examination including X-rays. Call now and a real person answers, or grab a slot online.
334 Manchester Road, Deepcar, Sheffield S36 2RH · Free parking