Salivary lactoferrin in a selected group of subjects with exceptional extrinsic dental staining

Some people exhibit an exceptional tendency to develop brownish extrinsic staining on their teeth and previous studies indicate that iron may be involved in certain types. The object of this investigation was to find out whether the level of salivary lactoferrin, which is an ironbinding glycoprotein, is elevated in persons exhibiting extreme staining tendency. Subjects who developed dark brownish discoloration on the facial surfaces of their anterior teeth during a 3-week period following professional cleaning of the teeth were selected for study. Salivary lactoferrin was measured by the enzyme-linked immunosorbent assay (ELISA). The results showed that this group of persons exhibited a markedly higher concentration of salivary lactoferrin compared with non-stainers. It was also demonstrated in an in vitro study that combinations of lactoferrin, iron, and tannic acid produced stain on slabs of enamel and dentin.