17. Black teeth were a sign of wealth in 18th century England. In 18th century England, sugar was a valuable commodity that was consumed in excess. Because it was expensive, it was mostly enjoyed only by the rich, like Queen Elizabeth I. As a result, if someone had black teeth, a sign of eating too much sugar, they were considered to be wealthy. My, how times have changed. Today, this has changed 180 degrees. Black teeth means no hygiene at all or sign of difficult life.