An ideal fixation system for guided bone (GBR) regeneration in oral surgery must fulfil
several criteria that includes the provision of adequate mechanical fixation, complete
resorption when no longer needed, complete replacement by bone, as well as be biocompatible
and have a good clinical manageability. For the first time, a biodegradable magnesium
fixation screw made of the magnesium alloy WZM211 with a MgF2 coating has been designed
and tested to fulfill these criteria. Adequate mechanical fixation was shown for the
magnesium fixation screw in several benchtop tests that directly compared the magnesium
fixation screw with an equivalent polymeric resorbable device. Results demonstrated
slightly superior mechanical properties of the magnesium device in comparison to the
polymeric device even after 4 weeks of degradation. Biocompatibility of the magnesium
fixation screw was demonstrated in several in vitro and in vivo tests. Degradation
of the magnesium screw was investigated in in vitro and in vivo tests, where it was
found that the screw is resorbed slowly and completely after 52 weeks, providing adequate
fixation in the early critical healing phase. Overall, the magnesium fixation screw
demonstrates all of the key properties required for an ideal fixation screw of membranes
used in guided bone regeneration (GBR) surgeries.
