I'm sure you heard the news already that "Crest toothpaste embeds plastic in our gums"
"The FDA, for its part, says it has never approved microbeads to be put in toothpaste, which it considers to be an over-the-counter drug. Polyethylene is allowed to come in contact with food, but there has been no ruling saying it is safe to consume"
http://www.dentalbuzz.com/2014/03/04/crest-imbeds-plastic-in-our-gums/
"The FDA, for its part, says it has never approved microbeads to be put in toothpaste, which it considers to be an over-the-counter drug. Polyethylene is allowed to come in contact with food, but there has been no ruling saying it is safe to consume"
http://www.dentalbuzz.com/2014/03/04/crest-imbeds-plastic-in-our-gums/