Abstract: A fountain tooth brush having a hollow handle for holding toothpaste and a screw shaft with a piston movable when the screw shaft is rotated for forcing the toothpaste from the hollow handle through a passage and into the removable brush head for applying toothpaste to the bristles. The rear end of the hollow handle is closed by a snap-on cap and the interior of the cap has a non-circular recess for receiving the adjacent non-circular end of the screw shaft so that a rotation of the cap will rotate the screw shaft. The brush head has a threaded neck removably receivable in the interiorly threaded bore of the hollow handle at a concave handle surface and the neck has diametrically opposed projections against which the forward end of the screw shaft contacts to prevent any forward movement of the shaft when disengaged from the cap.