Many people think that there is only one cause of yellow teeth, food and drink.
There are actually 4 causes of yellow or dark teeth and you can have one or more causes affecting you.
1. Food and drink: Coffee and soda are the two most common culprits of staining but why? Coffee contains acidic polyphenols called tannins that can lead to staining and discoloration, coffee is also acidic which slowly dissolves enamel and creates microscopic pits where staining food and drink gets trapped. Soda, has similar problems. This bubbly beverage is considered acidic to the body and, as a result, is damaging to your dental health. Here's the surprise, while the color of drinks can leave stains on teeth it is the acidity that can cause a snowball effect.
2. Naturally or Artificially thin enamel: Your teeth are made of three parts: the core of your teeth is made of soft pulp, this is where blood and nutrients are brought up through arteries in your jaw into your teeth. The next layer is called Dentin it is harder than pulp but not as hard as enamel. Dentin takes the nutrient-rich blood from the pulp and "extracts" out nutrients needed to keep your teeth healthy. Dentin is also off white, this is why if you have thin enamel your teeth may look yellow or dark. If you've ever bleached your teeth but just could not get your teeth bright enough it may be that you have thin enamel, if this is so, do not bleach your teeth! Bleaching can further thin your enamel.
3. Medications & drugs: Certain prescriptions and drugs can cause teeth darkening. Amoxicillin, ciprofloxacin and tetracycline can cause tooth discoloration. If you've used these medications for an extended period of time talk to your doctor and see if you can decrease your dose or change your medication. Certain "Street drugs" can ruin your teeth, cocaine & methamphetamine wreak havoc on your teeth, just say "no" kids! Lastly, fluoride can make your teeth discolored! Many people don't realize that fluoride can cause a condition called enamel fluorosis. If you are exposed to excessive fluoride while growing up, either through drinking water, oral care or dental visits, your teeth can trap too many fluoride crystals in your enamel causing a condition of the dental hard tissues in which the enamel covering of the teeth fails to crystallize properly, leading to defects that range from barely discernable markings to brown stains and surface pitting. Unfortunately, all of these causes are permanent and irreversible due to the total nature of their damage.