Can brushing your teeth with baking powder whiten your teeth?

It can clean them: If your teeth are discolored primarily because of extrinsic stain, like coffee, tea, or smoking, baking soda is an effective dentifrice and will make them look whiter. If the teeth are intrinsically dark or yellow, cleaning won't change that but tooth bleaching may be helpful. For most people it is a combination of both issues so cleaning and bleaching together can often be effective.

Maybe...: Brushing with baking powder or baking soda can remove extrinsic (outer) tooth stains simply because they can be more abrasive than regular toothpaste. Removing those stains can make your teeth appear a little whiter.