Ancient dentists recommended Portuguese urine as perfect whitening ingredient
Egyptians were the first to invent toothpaste many centuries ago, when there were no anti-cavity, mint-flavored and whitening toothpastes and gels. The ancient toothpaste was a mixture of pumice and wine vinegar. Yummy, isn't?
It may sound absolutely insane, but ancient Romans found a much more original way for their daily tooth-care. Wealthy Romans, especially women, were ready to pay a lot of money for the local sort of toothpaste, in which human urine was the main ingredient. They could not use their own urine or urine of another Roman: the "whitening toothpaste" was delivered directly from Portugal. Portuguese urine was supposed to produce a perfect whitening effect, if aristocrats were ready to pay for its delivery.
Urine was used for production of ancient toothpastes and mouth washing liquids before the 18th century. It really worked: urine contains ammonia molecules (which are still used in modern tooth-care industry) that whiten teeth very well.
When the Roman Empire collapsed, its oral hygiene traditions disappeared as well, although some people may probably say that using urine as mouthwash cannot be called hygienic at all.
http://funreports.com/fun/27-07-2005/1242-urine-0