Treatment for whitening of teeth is Bleaching of teeth, the longevity of it depends on oral habits.
Otherwise one can go for vineers which last longer than any teeth whitening.
Next Steps
Visit a dentist, get proper assessment of the situation & condition of teeth.
Health Tips
Scaling & polishing is must before teeth whitening. Teeth whitening by bleach should be avoided if there is any crack of the teeth or any cavity.
Final decision is to be taken by the concerned dentist only.