Does Crest Pro-Health Rinse stain teeth brown?, su news.crest.com, Crest. URL consultato il 6 giugno 2016 (archiviato dall'url originale il 6 marzo 2016).
«Tooth discoloration could actually be one indication, in some people, that the product is working: after the rinse kills germs in your mouth, the dead germs can collect on the tooth surface and create the appearance of a brown stain.»