Fig. 3.

Approximate positions of the defect/implant sites used for the in vivo studies. a) Subperiosteally placed magnesium fixation screws in combination with a collagen membrane on the buccal side of the mandible of Yucatan minipigs. For each animal, half of the mandible was implanted with five magnesium fixation screws fixating circular sections of a collagen membrane (Bio-Gide, Geistlich). The position of each magnesium screw was marked by non-resorbable titanium screws (1.5 mm × 3 mm ProFix titanium screws, Osteogenics) The titanium screws are represented by screw heads in a diamond shape. The images b), c) and d) represent the surgical intervention performed on Beagle dogs in the in vivo performance study. b) In a preparatory surgery, four teeth between the mandibular second premolar to the first molar (PM2 to M1) on each side of the lower jaw and the corresponding teeth of the upper jaw were surgically extracted. c) After a healing period of 12 ± 2 weeks, two independent bone defects were created on each side of the lower jaw. The defects were filled with bone substitute material and covered with collagen membrane fixed with either 4 titanium or magnesium fixation screws (2 on buccal and 2 on lingual side). d) For histological evaluation, sections were taken from the central region of the defect (orange area) and from the position of the fixation screw (blue area).