Over time, your teeth darken as minerals penetrate their outer enamel layer. This darkening can be caused by foods and beverages that stain such as coffee, tea, red wine, berries and tobacco products like cigarettes, can cause teeth to take on a yellowish brown hue. The natural ageing process can also cause your teeth to darken.
There is a tray method for whitening. Whereby trays are made in the laboratory to perfectly fit the teeth. A whitening gel is then placed into the trays and worn for approximately two and a half hours. This process can usually take two weeks to achieve the desired results, depending on the shade at which you start.
The advantages of the tray method are that each patient can judge their shade so that with persistent use over 2-3 weeks they can achieve their favoured result.