You should be careful of products that claim to whiten the teeth. Many don't do so; others can actually harm your teeth. Many teeth whitening products contain hydrogen peroxide that can make the teeth of some people extremely sensitive - they will pain when hot/cold or sweet/sour products are ingested. And if your teeth are already sensitive, you don't want to make them any worse.
If a tooth-whitening product contains at least 10% carbamide then it will whiten your teeth. Your dentist will usually supply these products. Over the counter products containing hydrogen peroxide have limited success. The natural saliva in the mouth may wash off the kind you brush on and leave overnight, giving a mottled whitening effect. There are strips you can apply for 30 minutes, but uneven bleaching could result if they don't conform to the ridges in your teeth.
You can get bleaching trays from the dentist; they are fairly costly, but relatively successful. Another procedure offered by your dentist is extremely expensive, but has the best results. It is laser treatment that is used to activate a bleaching gel applied to the teeth. The good thing is that it only takes one treatment; the bad side is that the cost is around four figures.
