Teeth stains can have various causes, and they can be categorized into two main types: extrinsic and intrinsic stains.

Extrinsic stains are caused by external factors and affect the outer layer of the tooth, known as the enamel. The most common causes of extrinsic stains include:

• Food and drinks: Certain foods and drinks, such as coffee, tea, red wine, and dark-colored berries, can stain teeth.

• Tobacco use: Both smoking and chewing tobacco can cause teeth to yellow or brown.

• Poor dental hygiene: Inadequate brushing and flossing can lead to plaque buildup, which can cause teeth to discolor.

• Medications: Some medications, such as antibiotics and antihistamines, can cause teeth to yellow or gray.

Intrinsic stains, on the other hand, are caused by internal factors and affect the inner structure of the tooth, known as the dentin. The most common causes of intrinsic stains include:

• Aging: As we age, the enamel on our teeth becomes thinner, revealing the yellowish dentin underneath.

• Genetics: Some people may be more prone to teeth discoloration due to their genes.

• Trauma: Trauma to the teeth, such as from an injury or root canal treatment, can cause the teeth to become discolored.

• Illness: Certain illnesses or medical treatments, such as chemotherapy or radiation therapy, can cause teeth to become discolored.

Overall, maintaining good oral hygiene and avoiding foods and drinks that can stain teeth can help prevent teeth stains.