Should You Brush Your Teeth Before Whitening?

Q: Should you brush your teeth before whitening?

Yes. Philips and Ultradent both tell you to brush before your whitening trays go in, and Philips adds flossing. Clean teeth mean plaque and food debris are not trapped under the gel.

Q: How long should you wait after brushing to whiten?

Tray gel instructions do not set a waiting time. If your gums feel tender, Healthline's advice for whitening strips is to wait at least 30 minutes after brushing.

14 octobre 2026

Short answer

Yes. Philips and Ultradent, the makers of Zoom and Opalescence, both tell you to brush before your whitening trays go in, and Philips adds flossing. Clean teeth mean plaque and food debris are not trapped under the gel.

Why brush before whitening?

Healthline, in an article reviewed by a dentist, explains that brushing and flossing first removes plaque and food debris that could otherwise get stuck beneath the whitening product. That lets the gel sit directly against clean teeth.

Should you floss before putting in whitening trays?

Yes. Philips' patient instructions for Zoom take-home whitening say to floss and brush your teeth before starting each whitening session. Flossing clears the gaps between teeth, where a toothbrush does not reach.

How long should you wait after brushing?

The Opalescence and Zoom instructions do not set a waiting time for tray gels. If your gums feel tender, Healthline's advice for whitening strips is to wait at least 30 minutes after brushing, because whitening straight after brushing can irritate the gums.

Should you brush after whitening too?

Yes. Ultradent's directions for Opalescence Go are to remove the trays after the wear time and brush your teeth. Its FAQ recommends a quick brush both before and after whitening.

What if your teeth are sensitive?

Philips advises people with very sensitive teeth to use a toothpaste for sensitive teeth every day for two weeks before starting a whitening course.

A simple routine

Floss.
Brush with your usual toothpaste.
Place your trays and wear them for the time on your product.
Remove the trays and brush again.

Sources and evidence

Healthline, "Should You Brush Your Teeth After Using Whitening Strips?" (2020, reviewed by a dentist): why brush first, waiting time.
Philips, Zoom take-home whitening patient instructions (2022): floss and brush before each session.
Philips, Zoom whitening gel FAQ: sensitivity toothpaste before a course.
Ultradent, Opalescence Go instructions for use (2020) and Opalescence FAQ: brush before and after.