Teeth whitening toothpaste is one of the latest marketing tools or alleged added functions of many brands.
I have also read several blogs or journalists who have had teeth whitening laser treatment and claimed it wasn't "7 shades brighter" or whatever was claimed, essentially claiming they were fooled out of money.
Is there reliable research to back up claims by toothpaste companies or by laser whitening services?
Usually the measuring tool is a card with different shades of white and you measure yourself against one and then after a certain period of time you claim you are now x# of shades lighter.