According to Catullus 39 (the Egnatius poem) Spaniards brushed their teeth with human urine (Catullus found the practice repulsive); it also worked quite well as a mouthwash. There is evidence that Roman women prized imported Portuguese urine for its strength during the first century-- probably a result of the long overland supply route than to any real ethnic characteristic.

Urine saw use as the active component in toothpaste and mouthwash until late in the 18th century-- ammonia gave it its cleansing power. Ammonia continues to be an ingredient in most modern dentrifice.