What causes tooth sensitivity?
Tooth sensitivity is usually caused by exposed dentine on your teeth. Teeth have 3 layers. Enamel is the outer shell, dentine is the middle layer, and the pulp is the inner most layer.
The pulp is the living part of the the tooth containing the nerve and blood supply. Dentine directly overlays the pulp and can be porous. When dentine gets touched, the nerves in the pulp can sense the change though the pores, and respond by sending a pain signal to your brain. This painful sensitive response is common, especially with hot, cold and sweet stimuli. The sensitivity is usually a sharp sensation and lasts just for the duration of exposure to the stimulus, but can sometimes linger for a few seconds.
Normally the dentine in your teeth is shielded by the outer layer of enamel or under the gum. Some things can however cause the enamel and/or gum to wear away and so expose the sensitive dentine:
Dental decay can cause cavities through the enamel into the dentine.
Tooth wear and trauma
Overzealous brushing, acid from your diet or stomach, grinding your teeth and trauma can all cause enamel to wear away and expose sensitive dentine.
Defective dental restorations
A lost, leaking or broken filling, cap, crown, onlay, inlay, veneer or bridge can also expose dentine and cause tooth sensitivity.
Gum recession and gum disease
Gums naturally recede with age which exposes the root surfaces of teeth. The root surfaces do not have protective layer of enamel and so can be sensitive. This process of gum recession can be sped up with overzealous brushing. Conversely infrequent or inefficient brushing can cause gum disease which can also lead to gum recession.
Some sensitivity following dental treatment is fairly normal. Especially after a scale or deep clean, after any drilling or placement of a new filling, and with tooth whitening. Most post-operative sensitivity resolves in 2-3 weeks. If you are experiencing severe sensitivity or there is no improvement after a couple of weeks then you should contact your treating dentist for advice.
How to treat tooth sensitivity
Treating sensitive teeth at home
Generally speaking, most ongoing tooth sensitivity is caused by gum recession and/or tooth wear. A good first line home treatment is to switch to an electric toothbrush, avoid scrubbing your teeth, and use a good sensitive toothpaste.
Not all sensitive toothpastes are equally effective. Some work in different ways.
Colgate’s Sensitive Pro-Relief, Sensodyne’s Complete Protection and Repair and Protect ranges are some of the best sensitive toothpastes on the market.
Sensitive toothpastes are readily available in supermarkets and pharmacies. Be careful shopping online and in budget high street stores to avoid cheaper foreign versions which may not meet UK guidelines.
Sensitive toothpastes generally take a couple of weeks to work. If you find after 2-3 weeks that your sensitivity has gone then you may just need to continue using the sensitive toothpaste. If after 3 weeks, the sensitivity is no better, then you should definitely contact a dentist for further advice.
Treating sensitive teeth at the dentist
In order to treat tooth sensitivity effectively you really need to determine the cause. The best way to find the cause of and treat your tooth sensitivity is to book a checkup with your dentist.
If the cause of your sensitivity is dental decay, tooth wear, trauma, a crack or a problem with a dental restoration, or gum disease then you may need some dental treatment such as a new dental restoration, root canal treatment or special cleaning.
Dental decay, tooth wear and gum disease will likely require special advice on brushing and cleaning cleaning techniques, specific diet advice and/or further investigations by the dentist (and possibly also with your doctor).
Sometimes the dentist can apply a desensitising varnish or paste to your exposed dentine.
Currently, due to COVID-19, most NHS dentists are prioritising face-to-face appointments for emergencies. Depending how severe your tooth sensitivity is and the current demand on local services, your dentist may be able to help with your sensitivity over the phone or may advise you attend a face-to-face appointment. You should check your dentist’s website or call them for advice on booking an appointment.