Biomechanical Effects Of Different 3D Printing Materials On Alveolar Defect Reconstruction Scaffolds:finite Element Analysis

Objective: The stress-strain-deformation distribution of scaffold mesh of different materials and thicknesses was analyzed by three-dimensional finite element method,which provided a reference for the design of personalized scaffold mesh from the biomechanical point of view.Methods: After extracting the CBCT data of the maxilla,three-dimensional reconstruction was performed on the 21-23 bone defect area.Based on this,three-dimensional finite element models of scaffold mesh of different materials and thicknesses were designed.Stress,strain and deformation of scaffold meshes were analyzed.Results: The stress,strain and deformation of the scaffold meshes and retaining nails of the five materials were decreased obviously with the increase of thickness.The maximum stress of the retaining nails under the two thickness meshes was less than their yield strength.At 0.5mm thickness,the maximum stress of the Ti alloy mesh was less than its yield strength,and the maximum stress of the other four materials was greater than their yield strength.At 0.6mm thickness,the maximum stress of Ti alloy,Mg alloy and PEEK mesh was less than their yield strength,and the maximum stress of the other two materials was still greater than their yield strength.The maximum stress of the scaffold meshes of 0.5mm and 0.6mm thickness was: Ti alloy>Mg alloy>PEEK>PLA>HA,the maximum strain and deformation was: Ti alloy<Mg alloy<PEEK<PLA<HA.Conclusion: The HA and PLA scaffold meshes of 0.5mm and 0.6mm thickness had a small load carrying capacity,which can't meet the clinical demand of oral GBR under immediate loading.The maximum equivalent stress of Ti alloy mesh of 0.5mm thickness and Ti alloy,Mg alloy and PEEK mesh of 0.6mm thickness were within the safe range and can meet the clinical needs.The elastic modulus of Mg alloy scaffold mesh is the most similar to that of autogenous bone,which can lead to good bone healing,and is biodegradable to avoid secondary surgical.Therefore,it is an ideal scaffold mesh material for oral GBR under immediate loading.