Whitening and Sensitivity
Why whitening makes teeth reactive, how long the twinges usually last, who is most likely to get them, what you can do, and the signs that something else is going on.
Why Are My Teeth Sensitive After Whitening, and Is That Normal?
It's normal. To reach the stain, peroxide gel moves through the enamel, and while it's active the tooth reacts more strongly to cold. The sensitivity is temporary and harmless, and it normally fades within a few days of your last session. Using a sensitive toothpaste from the outset, wearing the trays for less time or taking a night off keeps it under control. At our Lanark practice, your dentist examines you beforehand and oversees the course, so let us know if it's severe or won't settle.
Why Whitening Causes Twinges
Beneath the enamel lies dentine, a layer packed with tiny fluid-filled channels that lead towards the nerve. To get to the stain, the peroxide gel passes through the enamel and into this dentine. While it's there, the nerve reacts more readily, so a cold drink, a gust of chilly air or even brushing can set off a sharp twinge that's gone within seconds.
Some people also get sudden "zingers", a brief jolt in one tooth for no obvious reason, usually in the first part of the course. They're unpleasant but do no harm. Your enamel isn't wearing away and the nerve isn't being injured. When the course finishes and the gel has cleared, the tooth returns to how it was.
How Long the Twinges Last
Sensitivity usually comes and goes while you're whitening and calms down within a few days of your final session. It's often strongest a few hours after you take the trays out, and some people find the second and third days the hardest before things improve. Many notice it getting easier as the course goes on.
It can briefly return when you top up later. Top-ups only take a few nights, so it's usually mild, and the same tips below work just as well.
A Question About Sensitivity?
Send us a message before or during your course and a dentist will reply with advice.
Who Is More Likely to Feel It
It can happen to anyone, but it's more likely if your teeth are sensitive to begin with. Typical causes include:
- Receding gums that leave root surface exposed, where there's no enamel
- Enamel worn thin by heavy brushing, grinding or acidic drinks
- Hairline cracks or worn biting edges
- Older fillings that have started to leak at the edges
- Decay or gum disease that hasn't been treated, which we always deal with before whitening
This is why you'll have a dental examination before whitening is prescribed. If we spot a likely cause, we plan for it, whether that means treating it, starting a sensitive toothpaste early or adjusting how you whiten. A single tooth that already hurts before you start needs checking on its own, because whitening won't fix it and might aggravate it. The common causes are explained in our guide to sensitive teeth.
Easy Ways to Ease It
| What to do | How it helps |
|---|---|
| Use a desensitising toothpaste, starting two weeks before | It seals the dentine channels. Spit rather than rinse, and smear a little on tender areas before bed |
| Wear the trays for less time | The gel touches the teeth for less time; increase gradually as they get used to it |
| Whiten every other night | The nerve gets a break. It's slower but ends at the same shade |
| Go easy on ice-cold food and drink | Fewer triggers while teeth are reactive; sip cold drinks through a straw |
| Leave brushing for a while after a session | Rinse with water, wait around an hour, then brush gently |
| Remove extra gel | Stops gel staying on teeth and gums for longer than it should |
Usually one or two of these changes is plenty. For an uncomfortable evening, the painkiller you normally take for a headache is fine, though most people get through the course without one.
Sore Gums Are a Separate Issue
When gel sits on the gum, it causes a different problem: a tender or white patch where it touched. It can look worrying, but it usually disappears within a few hours once the gel is wiped away. It comes from overfilling the trays or from trays that don't fit well. Trays made from a scan of your teeth keep the gel where it belongs, which is why we don't use one-size-fits-all trays.
Put in the amount of gel we showed you and wipe away anything that oozes out. If a gum feels sore, use less gel next time. Stop and contact us if a white patch is still there the next day or your gums are bleeding.
When to Get in Touch
Ordinary whitening sensitivity is brief, sharp and set off by cold. Please contact us if:
- The pain is severe, wakes you at night or makes eating difficult
- It hasn't gone several days after you stopped
- One tooth is much worse than the rest, or hurts when you bite
- An ache continues well after the cold drink has gone
- Your gums bleed, or there's a white or painful patch on them
These can point to a cracked tooth, decay or an inflamed nerve. The whitening won't have caused them, but they need treatment of their own. Call 01555 662441 or message us on WhatsApp, and a dentist will advise whether to pause, change your routine or come in. Taking a few days off costs you nothing, as your trays and gel will still be there.
Whitening If Your Teeth Are Already Sensitive
Mild sensitivity doesn't usually stop you whitening. A sensitive toothpaste, shorter sessions and every-other-night wear are normally enough, and you end up at the same shade, only a little later. If sensitivity has a particular cause, such as an exposed root or a leaking filling, sorting that out first often makes the whole course easier.
Boutique home whitening at our Lanark practice is £350, or £315 for plan members, and it's included with every Invisalign and bonding package. 1 In the UK, a dentist has to prescribe it, and your dentist keeps an eye on you throughout.
Questions
This guide is general information, not a diagnosis. A dentist needs to examine you to say what is right for your teeth.