[Bone contact of miniscrews with and without a pretapped thread]

Better contact between screw and bone when using 2 mm AO-Miniscrews in the human midface is achieved if the thread is not pre-tapped. This could be demonstrated on metacrylate sections. In most implants with pre-tapped threads the bone does not fill out the space between the threaded core and the pretapped hole. The average measured distance between screw and bone is 110 microns. The contact surface between bone and screw is considerably greater than with pre-tapped threads.