Some people are born with teeth more yellow than others. Others have teeth that turn yellow with age. Several factors may alter the natural color of your teeth.
The surface stains (extrinsic stains) can be caused by:
Tobacco
The consumption of coffee, tea or red wine
Highly pigmented foods such as cherries and blueberries
A tartar by calcification of the plate
The colorations internal (intrinsic stains) can be caused by: Treatment with tetracycline during the formation of teeth
The yellowing or grayish appearance are part of aging
Trauma that can lead to death of nerve and give dental tooth color brown, gray or black. An excessive intake of fluoride during tooth formation (between birth and age 16 years) that gives teeth a "spotted".