A toothbrush having an improved cleaning and abrasion efficiency, wherein the bristles are comprised of synthetic thermoplastic polymeric compositions, and contain longitudinal channels extending along the length thereof, having a depth sufficient to entrap a quantity of abrasive particles such that...http://www.google.co.uk/patents/US6138314?utm_source=gb-gplus-sharePatent US6138314 - Toothbrush with improved cleaning and abrasion efficiency
