Who Invented the Toothbrush and When Was It Invented? Science Reference Services, Library of Congress, undated (in the category Everyday Mystery) http://www.loc.gov/rr/scitech/mysteries/tooth.html
("The bristle toothbrush, similar to the type used today, was not invented until 1498 in China. The bristles were actually the stiff, coarse hairs taken from the back of a hog's neck and attached to handles made of bone or bamboo. Boar bristles were used until 1938, when nylon bristles were introduced by Dupont de Nemours")
(c) Ming Dynasty (1368-1644)