Toothbrush with bristles having intermediate roughened portion

A toothbrush comprising:

• a handle portion,
• a head portion having at one end of said handle portion,
• said head portion having a plurality of individual bristles having a predetermined diameter extending out from said head portion, each bristle comprising:
• a stabilizing post portion which is rigidly attached to and extends out from said head portion, said stabilizing post portion having a peripheral surface which is smooth,
• a roughened portion having a net diameter no greater than said predetermined diameter of said individual bristles, and extending out from said stabilizing post portion, said roughened portion having a peripheral surface, said peripheral surface comprising a multitude of adjacent grooves and lands which cause said peripheral surface to be roughened and more abrasive than said post portion, and
• a tip portion at an end of said bristle opposite said stabilizing post portion and extending out from said roughened portion and forming a free end of said bristle distal from said head portion, said tip portion also having a peripheral surface which is smooth,
• and wherein each bristle may have a plurality of said roughened portions.