The effects of whitening are thought to last up to three years. However, this will vary from person to person. The effect is less likely to last as long if you smoke, or eat or drink products that can stain your teeth. Ask your dentist for their opinion before you start the treatment.
Whitening treatments help to reduce existing stains, but through consumption of coffee, soft drinks or just through natural ageing, your teeth may eventually become discolored again. Only Philips Zoom at-home whitening products include ACP, which has been shown to help reduce whitening fade-back.