What causes sensitive teeth?

Sensitive teeth are often caused by exposed tooth roots or by worn tooth enamel. This can result in pain, especially to cold drinks, food, and air, but also to touch, hot, sweet and sour.

An illustration showing exposed dentinal tubules

The reason for the pain is exposed dentine – the inner substance of the tooth, which is normally covered by enamel. The enamel can get quite thin, especially where the tooth meets the root (at the gumline). The root is covered by a substance called cementum, which is easily worn away. Dentine contains little tunnels (dentinal tubules) that link to the nerves on the inside of the tooth, and when dentine is exposed, these nerves are stimulated, resulting in pain.

How do you stop sensitive teeth pain?

Use a toothpaste for sensitive teeth

The trick is to not just use sensitive toothpaste for brushing with, but to rub it onto the affected areas with your finger:

“Try this, get hold of some Colgate Sensitive toothpaste, can’t remember the exact name, Pro-Relief I think.

Last thing at night before you go to bed, brush your teeth as usual. Then get a small smear of the Colgate on your fingers and massage it in to the neck of the sore areas. Don’t rinse, don’t eat or drink anything else, go to bed!

The theory is that your saliva production switches off a bit during the night (otherwise you’d wake with a wet pillow!) and the paste will have a good few uninterrupted hours to work.” (Gordon Laurie, BDS)

If you’re lucky, this may work right away, but it may take some days for the desensitising effect to kick in. When using it as a toothpaste, make sure that you work the paste right into the bristles of the brush so that it doesn’t all fall off in a big lump when you first put it into your mouth.

How do sensitive toothpastes work?

Sensitive toothpastes work by plugging and sealing the open dentinal tubules, so the nerves don’t get stimulated. Most sensitive toothpastes contain potassium nitrate as the desensitising agent.

Some contain a combination of arginine and calcium carbonate, for example Colgate Sensitive Pro-Relief with Pro-Argin. Colgate claim that it provides “instant relief when applied directly to the sensitive tooth with the fingertip and gently massaged for 1 minute.” From personal experience, arginine may work better than traditional potassium-based toothpastes, though the scientific evidence is inconclusive 1

Another ingredient which can be effective is stannous fluoride. The old stannous fluoride formulations tended to stain teeth, but recently, there have been some new products which don’t appear have this problem, such as Oral B’s inaptly named Gum and Enamel Repair (it doesn’t actually repair gums). It’s called Crest Pro Health in the US. Try this if you’re not having any luck with Pro-Argin.

Desensitising toothpastes can be used indefinitely. The warning on the US packet not to use Sensodyne for more than a month is a legal requirement, designed so that people won’t put off seeing a dentist when something might be seriously wrong. There are no health reasons for not using desensitising agents long-term.

High-fluoride mouthwashes

You may want to try a non-alcohol mouthwash with a high fluoride content. There are mouthwashes specifically designed to reduce sensitivity, for example those containing the Pro-Argin technology mentioned above.

Swish the mouthwash back and forth between the teeth for at least 30 seconds, spit out, and do not rinse with water afterwards.

The concentration of fluoride tends to be higher in toothpastes, so you may want to use desensitising mouthwashes at other times of the day, rather than after brushing your teeth.


Some people also find that GC Tooth Mousse and GC MI Paste help (these are quite expensive though).

What can dentists do about sensitive teeth?

  • Depending on the cause of the sensitivity, your dentist or hygienist may be able to paint special fluoride gels, rinses or varnishes onto the affected teeth.
  • If this doesn’t help and you can’t put up with the sensitivity, your dentist can seal or put bonding around the neck of the tooth, to cover exposed dentine. You should try all other options first though.
  • If you grind your teeth in your sleep, ask your dentist about having a mouthguard made to wear at night.

The information on this page has been provided by the Dental Fear Central Web Team. Last reviewed on September 27, 2019. We welcome your feedback on our information resources.


Illustration of exposed dentinal tubules: reprinted from Journal of Oral Biosciences Volume 59, Issue 4, Ji won Kim and Joo-Cheol Park, “Dentin hypersensitivity and emerging concepts for treatments”, Pages 211-217, November 2017, with permission from Elsevier.

  1. Arginine-containing desensitizing toothpaste for the treatment of dentin hypersensitivity: a meta-analysis. B Yan, J Yi, Y Li, Y Chen, Z Shi. Clin Cosmet Investig Dent. 2016; 8: 1–14.