Whats the cheapest way to whiten my teeth?

I used to have really white teeth but now they are quite yellow and I have some silver fillings that seem to have turned black..Please Help
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Do not use whitening toothpaste or baking soda, it actually damages your teeth by scratching the surface of them, making little scratches for the staining to stay. Do not buy any 'whitening kits' off the street. You need to visit a dental practice where a dentist can help with any questions you may have and can monitor the whitening if you choose to have it. Your dentist may not even recommend you have it done but you may just need a simple scale and polish (which is alot less money lol) Home whitening from your dentist is simple and easy enough to use. First your dentist will take impressions of your teeth and send them to a lab. It should take approximately 1 week to made replica clear brace like moulds. These will be made of a rubber like material and will fit exact to your teeth. Your dentist will show you how to place the bleaching gel into the trays. They normally advise that you wear the trays for at least 6 hours a day for it to work. I would say if you can wear them at night when you are just going to bed and sleep with them in. This way it does not disrupt your lifestyle during the day. This in the practice i work at cost £300 for top and bottom jaw plus the bleaching gel. We give enough gel to last approximately 2/3 weeks. You can purchase more at your dentist. You can also have in surgery whitening. This will be a longer appointment of about 1-1 1/2 hours. Your cheeks will be retracted and gel will be placed onto your teeth, you will then be sitting under a light for about the time i said. This costs a bit more at £650. I work in a dentist and we only get very few people who say it was not for them. Sensitivity is the main reason for stopping as any of the methods will cause this. You can use sensodyne toothpaste to help with this. As for the silver fillings which have turned your teeth 'black' this is not entirely true. What has happened is your the wall of your tooth is very thin and you can just see the silver filling. The best way to get rid of this is to either have a compisite filling (white filling) which might not be be suitable. Or to have a crown on the tooth. The crown should last about 7-10 years if looked after. Hope i have helped. Sorry about the essay! :)
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