Why teeth darken
Why do teeth get stained or discoloured?
Teeth rarely yellow overnight. The colour shifts gradually, and the causes are usually a mix of habits, health and genetics:
- Smoking or chewing tobacco, which leaves brown, stubborn marks
- Strongly coloured food and drink such as coffee, tea, red wine, cola, soy sauce and berries
- Certain antibiotics taken in childhood, which can discolour teeth from within
- Genetics, since some people simply have darker or more yellow enamel
- Some mouthwashes, especially rinses with chlorhexidine or cetylpyridinium chloride
- Plaque build-up from missed brushing and flossing, which lets stains cling to the surface
- Too much fluoride from toothpaste, water or supplements while teeth were forming
Surface stains from food, drink and smoking usually respond well to whitening. Stains inside the tooth may lighten less, and our teeth discolouration page explains the other ways they can be treated.









