Different people's teeth have naturally different shades of white. Also, age dulls your teeth as does smoking, while certain foods and drinks such as coffee and red wine also leave stains. Avoiding habits and foods that discolor your teeth will help maintain their brightness. Brushing and flossing at home, and cleaning and polishing at the dentist will make your teeth sparkle and remove stains. But none of these will make a significant difference to your teeth's natural shade of whiteness.
There are, however, techniques that will whiten your teeth. These break down into bleaching and laser bleaching.
Bleaching: While, you can buy over-the-counter whitening kits to use at home, these are generally not very effective. With professional bleaching, the dentist makes rubber 'impressions' of your teeth. These serve as trays to hold the bleaching gel in place, which you should apply for 30-60 minutes, 2-4 times per week. The whitening effect can last from a few months to a few years.
Laser (light-accelerated) bleaching is carried out by the dentist. He will protect your gums by placing a rubber seal round your teeth. Bleaching gel is applied to your teeth then a special light is shone on them to accelerate the whitening process. The entire session will last 30-60 minutes.
Both forms of whitening may cause some sensitivity of your teeth and gums for 1-3 days after completion of the treatment.