Private Dental Practice, Rr. Jan Kukuzeli, Nr. 4, 1010 Tirana, Albania.
Med Hypotheses. 2012 Aug;79(2):219-21. doi: 10.1016/j.mehy.2012.04.044. Epub 2012 May 25.
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.
牙齿上的外源性黑色污渍与龋齿发生率低有关，其主要成分是一种三价铁化合物。目前尚未完全了解其组成成分以及形成原因。研究表明，食用奶酪的人群龋齿发生率较低。乳铁蛋白是牛奶中的主要铁结合蛋白，在奶酪制作过程中几乎保持完整，具有抗致龋变形链球菌的抗菌活性。乳铁蛋白对铁具有高亲和力，只要存在铁，它就会结合铁，并仅在 pH 值<4 的情况下释放铁。在我进行的一项小型牙科实践调查中，患有外源性黑色牙渍的患者（未报告服用任何药物；牙龈无频繁出血）每天食用超过 50 克奶酪，其中许多人除了奶酪外，还每天饮用一杯牛奶。奶酪在牙齿表面停留的时间比牛奶长，而牛乳铁蛋白有四个聚糖链，可能有助于更好地附着。外源性黑色牙渍由三价铁化合物组成，而大量食用奶酪的人（乳铁蛋白在其中起着核心作用）会出现黑色牙渍。唾液中必须有足够的铁，乳铁蛋白才能结合铁，从而使黑色牙渍显现出来。在缺铁性贫血和铁过载中，唾液中存在的铁浓度明显高于无贫血的个体。因此，如果没有服用铁补充剂或个体没有频繁牙龈出血，那么牙齿上的外源性黑色牙渍可能是铁饱和的牛乳铁蛋白，是缺铁性贫血或铁过载的一个迹象。
