Why Did My Gums Turn White After Teeth Whitening?

Whitening gel contains hydrogen peroxide or carbamide peroxide. Gum tissue is thin and delicate, and when the gel reaches it, the peroxide irritates the surface layer. The tissue loses its pink colour and turns white or pale grey, usually with a tingling or stinging feeling.

This is a mild chemical burn of the surface, and not a sign that the gum is dying or that the tooth is damaged. Gel leaks onto gums from loose strips, ill-fitting trays and overfilled trays, and it can also happen during a professional session if the barrier protecting the gums is imperfect.

In most cases the white patch fades within hours to a day or two, and the colour returns to normal as the surface layer heals. The tissue underneath is not harmed in the way a deeper burn would be, which is why the change looks dramatic but resolves quickly. Mild soreness can last about as long, and the gum may feel rough or sensitive to hot, spicy or acidic food for a short while.

There is a range. A brief contact with a low-strength gel settles quickly. A strong gel left in contact for longer takes longer to settle and can leave a sore or blistered area. If the colour has not returned after a few days, treat it as something to have checked.

Rinse your mouth gently with plain water, remove any tray or strip, and wipe off remaining gel. Do not use any more whitening product until the gum has fully recovered, which means the colour is back to normal and the soreness is gone, and do not start again at the same strength without understanding what went wrong.

For comfort, avoid very hot, spicy, acidic or crunchy food, alcohol-based mouthwash and tobacco, and brush gently with a soft brush around the area. If the soreness bothers you, a standard over-the-counter pain reliever can be used as directed on the label, with the usual cautions about stomach ulcers, kidney disease, asthma, pregnancy and blood thinners. Do not put anything strong, such as lemon, salt scrubs or home remedies, on the area.

Gums that are already inflamed, receding or bleeding react more strongly, because the surface is thinner and the blood supply closer. A gap between the strip or tray and the tooth lets gel wander. Crowded or uneven teeth make an ill-fitting tray more likely, and mouth breathing or a dry mouth can make the stinging worse.

Strong gels and long wear times raise the chance of blanching for everyone. Using a product at its stated strength for the stated time, and no more, is the simplest way to reduce it. Dryness helps too: a tooth surface blotted dry before the gel goes on lets the gel stay where you put it instead of sliding.

Apply the gel to the teeth only and keep it off the gum line. Trim strips so they do not overlap the gum, use only a thin amount of gel in a tray, and wipe away any that squeezes out. A tray should fit snugly. A loose one is a common reason for leakage, and dentist-made trays are designed to avoid it. See the page on home whitening safely, and the smile design service if you want the treatment planned by a dentist.

In a clinic, a protective barrier or dam is placed over the gums before the gel goes on. That barrier is the main safeguard, described in the professional whitening procedure. If you are using strips, the page on teeth whitening strips explains how to keep them off the gums.

Contact a dentist if you see blisters or peeling tissue, if the pain is severe or getting worse, if the white area has not faded after two to three days, or if the gum bleeds or swells. Also call if you swallowed a large amount of gel and feel unwell. Spreading facial swelling, fever, or difficulty swallowing or breathing needs urgent medical care.

If you already have gum disease, bleeding gums or recession, whitening is more likely to irritate, and these are best treated first. Gum irritation is also one of the points covered in whether teeth whitening is safe. Call the clinic to ask about an examination and what is suitable for you.