There r two types of stain which will be present on teeth
intrinsic stains due to flouride or due to pan masala and due to any medicine during development of tooth
extrinsic stains are due to tobacco habiit, tea stains, food particle stains, cigarette stains etc.
Extrinsic stains are on surface of teeth removed by full mouth scaling and polishing.
Intrinsic stain require bleaching
procedure to reduce or remove stain base on depth of stain.