What are exogenous stains caused by?

Exogenous stains are dental discolorations that originate from external sources, making environmental sources the correct reason for their occurrence. These stains can be caused by various factors, such as the substances we encounter in our daily lives or come into contact with, including food, beverages, tobacco products, and certain medications. For instance, coffee, tea, red wine, and the use of tobacco can lead to staining on tooth enamel due to the pigments and chemicals they contain, which adhere to the surface of the teeth.

In contrast, other options like genetic issues or internal body processes typically relate to intrinsic stains, which originate from within the body due to factors such as developmental disturbances or certain medical conditions. Dietary habits, while they can influence stain formation (through consumption of staining foods), are not categorized as environmental sources in the context required for identifying exogenous stains. Thus, the emphasis on environmental sources aptly describes the origin of exogenous stains.