When I sent for my replacement bottle of the tooth powder, I went to the Eco-Dent website instead of buying a bottle of the powder from an online retail site. I then saw they offered toothbrushes as well, with replaceable heads. The bristles are "welded" into the head of the brush, so there are no pockets where bacteria can grow. They are also made of recycled materials and are 100% recyclable themselves.
BUT the best thing about them is, they are made in Wisconsin (where I was manufactured)!