The growth of bone cells or soft tissue cells on a surface is preferentially determined by the microgeometry of the surface. The cross section sizes of grooves (44) of a certain size favor bone cell growth (I) whereas another certain size favors soft tissue (59) growth (II). Laser apparatus is disclosed to cut the grooves in prearranged patterns; the use of the grooves on implants (46) is also disclosed (53, 54).
