The SEMimages of the removed screws are reported in Fig. 11 at the
macro, micro and nano scale. The SEM observations were performed
on the collar and thread (crests and valleys) of each screw. An exemplifying area is reported for each sample, but analogous results were obtained on different zones of each screw and on four screws per type.
No difference was evidenced among screws implanted at different
torque force.