Researchers in Canada have found that adding milk to tea may reduce tea's ability to stain your teeth. Casein, the main protein in milk, binds to the tannins in tea and prevents staining.
Q: How does whitening work?
Your teeth are covered with enamel, the hardest substance in the human body. Enamel is largely made up of a mineral called hydroxyapatite, which is composed of calcium and phosphate ions arranged in rod-shaped crystals. Molecules of food and drink can become lodged between these crystals, discoloring the teeth.
Most whitening strips use a gel with carbamide peroxide or hydrogen peroxide. A peroxide is an oxidizing agent that steals electrons from molecules staining the teeth, disrupting the chromophore in the same way bleach cleans stains from clothes. Read more at www.cocofloss.com/whitening.