Tooth Blackening - The 2000-year-old beauty secret is based on the belief that only wild animals and demons have white teeth. The blackening of the teeth, was an assurance that one would not be mistaken for an evil spirit. Women with blackened teeth are seen as beautiful.At this point it is only the elderly women who continue the tradition.It was also beneficial, as it prevented tooth decay, in a similar fashion to modern dental sealants.