Comparison of shear strength of osteotomies fixed with absorbable self-reinforced poly-L-lactide and metallic screws

Nine experimental osteotomies on the neck of a sheep's left mandibular condyle were fixed with self-reinforced poly-L-lactide (SR-PLLA) screws. Metallic screws were used in a group of nine sheep for the same fixation of the osteotomy. The right condyle of each sheep acted as a control. Radiographic analysis was carried out at 3 weeks and at sacrifice (6, 12 or 24 weeks) when the shear force needed to break the osteotomy site was measured. No significant differences were detected at 3, 6 or 24 weeks, but at 12 weeks the SR-PLLA-fixed condyles seemed to tolerate shear force somewhat better.