Teeth colour darkening over the years is a natural process. Consuming coffee, tea, red wine and tobacco accelerates the loss of whiteness. To restore the desired teeth colour, it is necessary to whiten them. Only cleaned teeth without caries can be whitened. It is not possible to whiten aesthetic fillings, veneers, crowns etc. Teeth can be whitened in a dental office (shorter process) or at home (longer process). The process done in a dental office lasts 30-60 min, depending on the colour we wish to achieve. At home, the procedure with X-white stripes lasts somewhat longer; the stripes are applied for 10 days.