US Patent 8448286 Bristle tufts and toothbrush with bristle tufts

A bristle cluster for a toothbrush is provided. The bristle cluster includes a number of bristles of a first type and a number of bristles of a second type. The bristles of the first type have wear characteristics that differ from the wear characteristics of the second type. The bristles of the first type have a wear indicator which causes a color change of the bristles, and the bristles of the second type, upon continuous mechanical stress, undergo a visible mechanical change and the free ends of the bristles of the second type are designed to be capable of being longitudinally fanned out.