Whitening tooth paste generally which are available in the market basically have more abrasive content in them.
They have some silicates or aluminium oxides or carbonates. So they help in better abrasive action. Thereby they help in removing the surface stains like nicotine stains, coffee or tea stains.
That is the maximum they can remove. They try to remove the stains which are coated on the tooth rather than removing the colour of the tooth which is achieved by bleaching. So whitening tooth pastes are not like bleaching agents.
They are basically tooth pastes with higher amount of abrasives and try to whiten your teeth by removing surface stains.
► See also:Taking DENTAL IMPRESSIONS : Correction Impression
Fuente: Youtube / Doctors' Circle - World's Largest Health Platform