Whiten teeth with hydrogen peroxide

Hydrogen peroxide can alter tooth color in controlled whitening products, while concentrated or improvised use can irritate gums and oral tissues.

Whitening works mainly by oxidation of stain molecules within enamel and dentin. It does not change the color of fillings, crowns, veneers, or other restorations.

Use only a product and concentration directed by a dental professional or its labeled instructions; keep gel off the gums and stop if marked irritation develops.

Seek dental advice before whitening if there are cavities, cracks, gum disease, ulcers, exposed roots, or unexplained sensitivity.

Ask whether the discoloration is surface stain or internal, what concentration and wear time apply, and whether existing restorations will need another plan.