The outcome of professional teeth whitening can vary among individuals, but typically results in teeth that are 6 to 12 shades whiter, according to the whitening shade guide. The level of whitening depends on the extent of discolouration on the teeth before treatment. Teeth with surface stains, a yellow or brown tint, or uniform darkening usually respond better to treatment. For heavily stained teeth, additional whitening sessions may be necessary to achieve the desired brightness. Nevertheless, professional teeth whitening can effectively enhance the appearance of your teeth and smile.