Whitening toothpastes don’t work as well as they are advertised, as far as anyone can tell.
The truth is that age is the prime cause of yellow teeth.
Anything that causes outside stains on teeth is easily removed by a regular cleaning at the dentist and often times by regular flossing and brushing alone.
But most discoloration takes place below the enamel and is a natural part of a tooth’s aging process.
Most whitening toothpastes contain abrasives that polish the teeth and chemicals such as sodium tripolyphosphate that break down or dissolve stains.
There is plenty of evidence that using hard abrasives and corrosive chemicals on the teeth regularly can actually cause enamel loss and gum injury.
It’s important to have one’s dentist advise the best solution to stained teeth.