Why do my teeth hurt after whitening strips?

Why do whitening strips hurt my teeth?

The ADA says peroxide in whiteners can pass through enamel into the dentin and irritate the tooth's nerve, and that the sensitivity is usually temporary. Cleveland Clinic says temporary tooth sensitivity or gum irritation is common when you start using a whitening product and is not a sign of lasting damage, though it can be uncomfortable. Healthline says sensitivity usually starts during treatment, and that risk rises with higher peroxide concentration and longer contact time.

How long does it last?

Healthline says tooth sensitivity usually lasts several days, and gum irritation may appear within a day of treatment and typically lasts several days, both usually mild. Cleveland Clinic says symptoms usually resolve quickly but gives no number of days, and the NHS says side effects may last for a short time. If it lasts longer, tell your dentist.

Do whitening strips damage enamel?

Healthline says high hydrogen peroxide concentrations can harm tooth structure and make teeth more prone to demineralization, and cites one study that reported enamel structural damage from 35% carbamide peroxide. It says chlorine dioxide, used in some strips, may strip enamel and increase sensitivity and restaining. The ADA says overusing whiteners can harm enamel or gums, and to follow the directions and check with your dentist. Cleveland Clinic says sensitivity itself is not a sign of lasting damage.

Are whitening strips supposed to hurt?

Mild sensitivity is common, but pain that is strong or lingering is a sign to stop. The ADA suggests pausing treatment, letting the sensitivity fade and consulting your dentist before resuming, and Cleveland Clinic suggests taking a break from bleaching, switching to a milder product and following the directions on frequency and duration. Do not push through severe pain.

How can you reduce the risk?

Healthline says to choose lower peroxide concentrations and avoid leaving strips on longer than directed, since both increase side effects, to use strips for mild touch-ups rather than major color changes, to talk with your dentist before use and to look for the ADA Seal of Acceptance. The ADA says products with the Seal have been tested for safety and effectiveness. Cleveland Clinic recommends addressing issues like gum disease or cavities before starting whitening.

What about the gums?

The NHS says teeth whitening done by a dentist can make gums or throat sore and cause white patches on the gums, and that your dentist should use a protective shield or paste on your gums. It says kits bought from a pharmacy or online, or whitening done at beauty salons, work less well and may harm your teeth and gums, and that a dentist-prescribed kit is the safer option. Healthline says gum irritation typically lasts several days.

How long should strips be used?

Healthline says usually twice a day for about two weeks, each session around 30 minutes, though some products need only one daily application, and lightening may be visible within several days. Follow your product's directions rather than these averages. Our guides on how long to leave whitening strips on cover timing, and our guide on whether whitening strips are bad for teeth covers safety.

When should you not whiten at all?

Cleveland Clinic recommends addressing issues like gum disease or cavities before starting whitening, and Healthline notes that whitening does not change the color of existing fillings, crowns, bridges or implants. If you have sensitive teeth already, receding gums with exposed roots or visible decay, whitening may hurt more, which is general reasoning and flagged. A dentist can examine your teeth first and tell you whether strips are suitable.

Questions to ask your dentist

Take these to a check-up.

• Is my sensitivity from whitening, or something else?
• Which product and strength suit my teeth?
• Should I use a desensitizing toothpaste?
• Do I have decay, cracks or gum problems that need treating first?
• When is it safe to restart?

Frequently asked questions