Coffee
Over time, the natural color of a person’s teeth can become uneven. One of the most common causes is from consuming too much coffee. To understand how coffee causes yellow teeth, it is important to understand what makes teeth appear yellow in the first place.
For teeth to appear white and clean, the enamel must be bright and fresh. Enamel is created when an individual is still a baby and is almost 100% pure hydroxyapatite. As we drink coffee in excessive amounts, the enamel becomes thinner and less pure.
Fluorapatite has similar properties to hydroxyapatite but contains fluoride, which helps protect against tooth decay by strengthening teeth on a molecular level. The reason teeth appear yellow is that coffee contains tannins that interact with the fluorapatite in your teeth and cause yellowing or staining.
Also, coffee stains teeth because the polyphenols in the coffee, which are a large part of the reason coffee is so good for your health, are very good at staining skin. Polyphenols are great at penetrating the skin, and they do so with such force that they break through the skin, allowing them to penetrate deeper into your body; this same occurrence can happen with your teeth.
