Your teeth are constantly under attack, gradually staining from the colours in food, drink, and tobacco. These stains build up over time and will continue to do so after whitening also. Each time you whiten, you are removing years of staining. Although teeth do re-stain it’s very easy to maintain a white smile for life! After your initial treatments to remove old stains, most people only need a touchup 1-2 times per year to maintain their ideal results.