There is provided a toothbrush where the dose of dentifrice used is controlled by the use of bristles of at least two different colors. When the bristles of one color are covered with a dentifrice the dose will be within guidelines. In addition, the dentifrice and bristles of one of the colors can...http://www.google.se/patents/US5806127?utm_source=gb-gplus-sharePatent US5806127 - Coded toothbrush
