Intrinsic staining occurs inside the tooth’s enamel — the tooth’s external protective layer — and usually develops during childhood, when your teeth are growing and your enamel is still forming. Intrinsic staining can be caused by things like getting a really high fever, taking the antibiotic tetracycline, or consuming water with excessive amounts of fluoride. But your reaction to these events, and whether you develop these stains or not, will depend on your genetic predisposition, Grbic tells BuzzFeed Health.
“Because these stains are within the enamel, they’re most likely permanent and can’t really be removed,” he says. “That’s why patients will try to hide them by getting laminates — a thin layer that covers the surface of a tooth, generally used for aesthetic purposes, or a crown that covers the entire tooth.”
Extrinsic staining occurs on the outside of your tooth enamel and is primarily caused by ingesting things high in pigmentation, like nicotine (through smoking cigarettes) and foods or drinks that are high in a compound called polyphenol (such as coffee, red wine, and green tea). These types of stains can usually be removed, and often times prevented, Grbic explains.