Staining of teeth by beverages
The hypothesis that coffee will leave the most stains on our teeth has not been proven to be true; instead, grape juice caused the most discoloration.
Having a beautiful smile and white teeth is important to a lot of people. Many people visit dentists to obtain cosmetic whitening for discolored teeth. There are also a lot of teeth whitening products available in the market. Having stained teeth may be embarrassing to some and may affect their self-confidence; hence, it may be advisable to drink in moderation beverages known to stain teeth.
The science fair project may be repeated using different types of food like soy sauce, curry, black pepper sauce or chili sauce.
The experiment may also be done to compare stains left on fabric by food or beverages.
Teeth stains and discoloration - http://www.bellaonline.com/articles/art38900.asp
Foods and drinks that stain your teeth - http://www.dentalhealthsite.com/foods-drinks-stain-teeth/