Why Whitening Causes Sensitive Teeth

A Brighter Smile — But at What Cost?

Tooth whitening is one of the most popular cosmetic dental treatments today. But for many, it comes with an unwelcome side effect: sensitivity. That sharp, zinging pain when you sip something cold or breathe in cool air can catch you off guard — and it’s more common than you might think.

What’s Causing the Sensitivity?

Most whitening products use hydrogen peroxide or carbamide peroxide to bleach stains. While effective, these chemicals can penetrate the tooth enamel and irritate the soft layer underneath — the dentin — where tiny nerve endings live.

Some people also experience gum sensitivity if the whitening gel overflows or touches the gums. This can leave them feeling tender, inflamed, or even burning for hours after treatment.

Tips for Whitening Without the Ouch

• Use a desensitizing toothpaste for 1–2 weeks before whitening

• Avoid overfilling trays or letting gel touch your gums

• Space out your sessions — more isn’t always better

• Choose lower-concentration gels or shorter wear times

• Avoid acidic foods and drinks immediately after treatment

The Bottom Line

Whitening can be part of a healthy smile routine — but it should never be painful. If you’re prone to sensitivity, talk to your dentist about safe options or try whitening products designed for gentle use.