This excursion into American cultural history looks at the toothpaste and toothbrush industries from 1900 to 2008. During these years, America moved from cleaning their teeth mostly with homemade powders to using an enormous array of brands, often applied with an electric toothbrush. From early 20th century products like Forhan's (which "cured" pyorrhea) to the whiteners of the 1920s (which unfortunately also removed tooth enamel), and from paste that eliminated "that clinging film" and to copywriters who "wondered where the yellow went," the history of toothpaste has long been a testament to the power of misleading advertising. Interrupting a steady flow of hyperbole was the one true wonder ingredient—fluoride, which enabled Crest to be for decades America's top-selling brand.