Disclosed herein is a toothbrush with tapered bristles and method of manufacturing such toothbrushes. The toothbrush is characterized in that the tapered end of each bristle is 0.02 mm or less of diameter. The bristle is tapered starting at a position of 3.5 mm or less from an end, and is made of polyethylene terephthalate or polybutylene terephthalate. The method of this invention consists of the steps of dipping 3.5 mm portions from ends of monofilaments for toothbrushes into erosive chemicals...