Why Teeth Turn Yellow Even After Brushing and When Teeth Whitening Helps You can brush twice a day and still feel that your teeth look yellow. That does not necessarily mean you are brushing badly. Brushing removes plaque and some surface stains; it does not change every colour that develops inside a tooth or make naturally deeper-coloured teeth the same shade as porcelain. The useful question is not simply “Which whitening treatment is strongest?” It is “What is causing the