An improved bristle for toothbrushes having a spiral groove along the longitudinal shaft of the bristle to increase the abrasiveness and expand the surface area of the bristle used in cleaning, the grooved bristle is combined into tufts and mounted on a suitable platform so that when the surface to be cleaned is scrubbed with a toothbrush having the improved bristle of the invention the bristles twist and bend and in the process the shaft of the bristle scrapes on the surface to be cleaned and agitates the fluid in and around the area to be cleaned thereby increasing the cleaning ability of the brush.