Abstract: Objective: To study the effects of ultrasonic micro arc oxidation silane coupled silk fibroin composite coating on the bone consolidation and degradation of pure magnesium implants. Methods: After ultrasonic micro arc oxidation, pure magnesium implants were treated with NaOH and then with silane coupled silk fibroin on the surface for 0.5 h or 1.5 h, which were divided into group A, group B and group C, respectively. The modified materials were implanted in the rabbit mandible. Results: Scanning electron microscope observation showed that the surface of group C was the most compact. The concentration of magnesium in blood showed little change after compound modification. Torsion experiment demonstrated that the group C > group B > group A, showing statistical difference. HE staining, immunohistochemistry and gray value analysis showed that the group C had the strongest ability of bone consolidation. Conclusion: Pure magnesium implant with ultrasonic micro arc oxidation of alkali (NaOH) processing and silane coupling and silk fibroin composite modification showed better degradation rate and stronger promotion capability of osseointegration.

Key words: Pure magnesium, Silane coupling agent, Silk, Fibroin, Micro arc oxidation, Animal experiments