Enhancing bone formation using absorbable AZ31B magnesium alloy membranes during distraction osteogenesis: A new material study

PURPOSE: To investigate whether the use of absorble AZ31B magnesium alloys over distraction gaps improves the quality and quantity of regenerated bone better than the use of Collagen membranes. METHODS: Fifteen mixed-breed dogs were randomly divided into the experimental (n = 10) and control (n = 5) groups. In the experimental group, two devices were implanted along the mandible; one side with absorble AZ31B and the other side with Collagen. The control animals did not undergo osteotomy or distraction. After a consolidation time of two months, 30 specimens were harvested, and newly created bone was identified using CBCT and micro-CT. RESULTS: The Collagen membranes were absorbed completely, and the AZ31B membranes became irregular and rough. Mandible length was successfully extended approximately 1 cm. More bone formation was found after using AZ31B than Collagen, and there was a significant difference in width reduction between experimental sites treated with AZ31B (0.11 ± 0.04 cm) and Collagen (0.42 ± 0.06 cm) (p < 0.05). Trabecular thickness was also significantly higher in AZ31B (0.338 ± 0.08 cm) and control (0.417 ± 0.05 cm) than Collagen (0.178 ± 0.04 cm) (p < 0.05). CONCLUSION: An AZ31B membrane barrier is biocompatible and absorbable which can maintain the distraction gap and provide support to the attached osteoprogenitors by providing space for them to proliferate.