Why Are Teeth Sensitive?

Where the Twinge Comes From

Your enamel can't feel anything. The dentine beneath it is a different matter: it is softer than enamel and riddled with microscopic channels that lead inwards to the nerve. Once dentine is uncovered, a cold drink, a hot one, something sugary or even a gust of cold air shifts the fluid inside those channels, and the nerve registers the movement as a brief, sharp jolt. That is textbook sensitivity. It is set off by something specific, it is over in seconds, and it fades the moment the trigger is removed.

On the visible part of the tooth, dentine is protected by enamel; on the root, it is protected by gum. Anything that thins the enamel or pulls the gum back exposes it. Pain that carries on long after the trigger, or that arrives with no trigger at all, is another thing entirely and normally means the nerve is inflamed.

The Usual Causes

• Enamel wear, from heavy brushing with a hard-bristled brush, or from clenching and grinding that flattens the tips of the teeth
• Gum recession, which uncovers root surfaces that never had enamel in the first place. Gum disease and years of over-vigorous brushing are the common culprits
• Acid in the diet: fizzy drinks, citrus juice, wine and vinegary dressings soften the enamel surface so it wears away faster. Reflux attacks the teeth the same way from within
• A crack, a cavity, or a filling that is worn or leaking, all of which tend to affect a single tooth
• Tooth whitening, which can make teeth temporarily sensitive during the course of treatment
• Recent dental work, as a new filling or crown can leave a tooth reactive to cold for days or a few weeks while it settles

It is common for causes to stack up. A person who grinds at night, sips sparkling water all day and brushes hard is losing enamel to three separate processes.

Easing It Yourself

• Switch to a toothpaste made for sensitive teeth, brush with it morning and night, and spit without rinsing so the active ingredient stays put. Allow two to four weeks for it to work
• Before bed, dab a small amount onto the sore area with a clean finger and leave it there overnight
• Choose a soft brush and press lightly, tilting the bristles towards the gumline and using small circles instead of a back-and-forth scrub. If you tend to press hard, an electric brush with a pressure warning helps
• Drink acidic drinks with food rather than over several hours, try a straw, and swill with water after
• Leave about an hour between acidic food or drink and brushing, because enamel is briefly softened and wears more easily
• If you use a fluoride mouthwash, use it at a separate time of day from brushing

If whitening is behind it, our guide to sensitivity after whitening explains how to manage it, and it fades within days of pausing treatment.

Signs You Should Get It Checked

Most sensitivity is harmless and responds to the steps above. Come and see us if:

• The sensitivity is sharp and confined to a single tooth
• The ache hangs around long after the ice cream or cold drink, or turns up unprompted
• A tooth hurts when you bite down or as you release, which can be a crack
• There's a visible cavity, a dark mark or a chipped filling
• Your gums have visibly shrunk back or bleed when you brush
• A month of sensitive toothpaste hasn't made a difference

Any of these may mean a fracture, a cavity, a failing filling or nerve inflammation, and each is easier to fix when caught early. New patients pay £30 for a dental examination including two X-rays, and returning patients £30, and both are covered by our dental plans.² If a tooth is waking you at night, call 020 8788 6688 before 9.30am, Monday to Saturday, and we'll see you that day.

How We Treat It

The right treatment depends entirely on the cause, so we look closely at the tooth, with an X-ray if it's warranted, before recommending anything.

You'll receive a written plan with fees before any treatment, and dental plan members get 10% off most of it.²

When New Dental Work Feels Sensitive

After a filling, onlay or crown, a tooth often reacts to cold for anything from a few days to a few weeks while the nerve recovers from being worked on, and this generally fades by itself. Two things are not part of that normal settling and deserve a phone call. One is pain on biting that doesn't go away, which often means the new restoration is fractionally high and needs a minute or two of adjustment. The other is sensitivity that worsens over a fortnight instead of improving. Both are quick for us to check. Rarely, a very deep filling sitting close to the nerve later needs root canal treatment, so we would always prefer to hear from you than have you put up with it.

Stopping It Coming Back

With the cause dealt with, prevention comes down to protecting your enamel and gums.

• Stay with a sensitive or fluoride toothpaste, and carry on spitting instead of rinsing
• Use a soft brush and replace it, or the brush head, every three months
• Have acidic drinks only with meals, and wait before you brush
• If we've made you a night guard, wear it, because grinding cancels out everything else
• Attend your hygiene visits, where early recession and gum disease are picked up; our gum care guide sets out a full routine
• Let us know about reflux or frequent vomiting, as stomach acid erodes enamel fast and there are ways we can protect your teeth

Questions

This guide explains the options in general terms. Only an examination can tell you which of them suits your own teeth.