Are extrinsic black stains of teeth iron-saturated bovine lactoferrin and a sign of iron deficient anemia or iron overload?

Extrinsic black stains on teeth are shown to have a relation with a low incidence of caries and are made of a ferric compound. Whole composition and why those stains are formed are not fully understood. Studies have shown low incidence of caries in individuals eating cheese. Lactoferrin is the major iron-binding protein, constituent of milk, stays almost intact during cheese making and has antibacterial activity against dental cavity-inducing Streptococcus mutans. Lactoferrin has a high affinity for iron and whenever it is present it will bind iron and release it only in values of pH < 4. In a small survey that I made in dental practice, patients (patients did not report taking any medication; had no frequent gingival bleeding) that had extrinsic black stains on teeth eat > 50 g of cheese per day and a good number of them, in addition to cheese, drink one cup of milk per day. Cheese stays much longer in contact with tooth surface than does' milk and bovine lactoferrin has four glycan chains that may contribute to a better adherence. Extrinsic black stains are made of a ferric compound, and people that eat good amounts of cheese (where lactoferrin plays a central role) show to have black stains. Iron must be in sufficient amounts in saliva so that lactoferrin can bind it and as a result making the black stains appear. In iron deficient anemia and in iron overload the concentration of iron present in saliva is much higher than in individuals with no anemia. In conclusion, extrinsic black stains of teeth may be iron-saturated bovine lactoferrin and a sign of iron deficient anemia or iron overload if no iron supplements are taken or individuals have no frequent gingival bleeding. (C) 2012 Elsevier Ltd. All rights reserved.