How Long Does Teeth Whitening Last?

8 oktober 2026

Short answer

Whitening is not permanent. The NHS says the effect may last around 3 years, and a study that followed people after tray whitening found the colour largely held at one year, with a slight fade by 30 months. How long yours lasts depends mostly on what stains your teeth afterwards.

What do follow-up studies show?

One clinical study followed 60 people who whitened with 10% carbamide peroxide in trays for three hours a day over three weeks.

At one year, the whitening was stable once surface stains had been removed by a professional cleaning. Without the cleaning, the teeth looked slightly darker.
At 30 months, among the 43 people still in the study, there was a slight but measurable return of colour that cleaning did not remove.

An older study asked 30 people about their teeth roughly 10 years after tray whitening. 43% felt their colour had stayed stable. That figure is their own impression and was not measured.

What makes whitening fade faster?

The NHS and the American Dental Association both list coffee, tea, red wine and smoking as causes of tooth staining. New surface stain is the main reason whitened teeth look darker again.

Two findings may surprise you. In the 30 month study, smokers and non-smokers lost about the same amount of whitening. And avoiding coloured food and drink during the whitening course itself did not improve results, which we cover in our post on coffee and whitening.

How do you make it last longer?

Keep surface stain off. In the one year study, a professional cleaning was the difference between stable colour and slight darkening.
Use touch-ups. A dentist speaking for the American Dental Association told WebMD that after the first course, a touch-up about once a month is probably enough. A touch-up is a single session, not a repeat of the whole course. Prefilled trays such as Opalescence Go are single use, so they can be used one pair at a time.

Do crowns and fillings stay white too?

They do not change. The American Dental Association notes that only natural teeth whiten, so crowns, veneers and fillings keep the colour they had.

How strong is this evidence?

Limited. The largest review of whitening at home only followed people for up to six months, and the longer figures above come from one group of 60 people and one survey of 30. Individual results vary.