What condition is associated with bluish-green stains on teeth?

The presence of bluish-green stains on teeth is commonly linked to inhaling metallic dust due to occupational exposure, particularly to substances such as copper or other metal particles. This type of staining occurs because heavy metals can deposit on the enamel, leading to discoloration. Workers in industries like mining, welding, or manufacturing, where exposure to metal particles is higher, may present with these stains due to the inhalation of contaminated air.

Other conditions such as ingestion of food coloring or excessive fluoride use might cause discoloration, but they typically result in different color shades or patterns, and certain medications could lead to other types of staining as well. However, the distinctive bluish-green hue is most directly associated with the inhalation of metallic dust, making this option the most accurate in this context.