The number of treatments or sessions needed will depend upon your teeth and the degree to which they are stained. Some stains are deep in the dentin, or caused by antibiotics given to patients while their teeth were still forming. These types of stains can be more difficult to get out. For most clients however, whether due to drinking staining beverages such as coffee and wine, smoking cigarettes, or just simply due to age, they will be able to achieve dramatically whiter teeth in a single visit.