Here is home remedy for brighter teeth--- mix several teaspoons of baking soda with enough fresh lemon juice (or water) to make a paste.
Wipe your teeth and any extra saliva off of them with a paper towel.
Put a good amount of paste onto your toothbrush and apply.
Leave the paste on for 1 minute, then rinse, so as to avoid the acid effecting enamel.
If you are using just water you can leave it on for up to 3 minutes. For faster result you can go for teeth bleaching from dentist.