Synthesis And Properties Of PLA/HA Composite Scaffold Based On 3D Printing Technique

Objective: To explore the synthesis and properties of 3D printed PLA/HA composite scaffold of different HA content and its application possibility as personalized root implants.Methods: The PLA/HA composite scaffold materials with different HA content(1 wt%,5 wt% and 10 wt%,respectively.)was prepared with solution blending method,and the test specimens was printed by using fused deposition modeling.Then,microstructure,thermal stability and mechanical properties of PLA/HA composite scaffold were detected by SEM,thermogravimetric analysis and tensile test,respectively.The cytocompatibility of 3D printed PLA/HA composite scaffold material was examined by CCK-8 assay.Based on the CBCT image data of rabbits,a personalized anatomical tooth root was designed and immediately implanted into the alveolar cavity of the lower jaw of rabbit.Changes of the implant were observed.Results: SEM results show that HA is uniformly dispersed in PLA matrix.The large pores and small pores coexist in the scaffold material.The pores are distributed evenly and the interiors are interconnected with the pores ranges from 200 μm to 500 μm.Contact angle of material with 1 wt % HA,5 wt % HA,10 wt %HA are 76.4°,75.5 ° and 76.2 °,respectively.Contact angle of PLA/HA composite scaffold is reduced compare to the pure PLA.Thermogravimetric analysis shows that the HA content markly affects the thermal degradation temperature(280 ℃~320 ℃)and the thermal degradation rate of the 3D printed PLA/HA composite scaffold material.The degradation residue increases with the increasing proportion of HA.Tensile test results display that the tensile fracture stress of the 3D printed PLA/HA composite porous scaffold is 20 MPa to 35 MPa.The elastic modulus is between 0.8 GPa and 1.1 GPa,and the rigidity increases at first and then decreases with the increase of HA.Data from CCK8 assay shows that survival rate are 94.39%,95.50% and 95.91%,respectively.Printing error analysis results show no statistical significance(P).Immediate implant experiment shows that there is no obvious loosening of the implanted root implant,and no obvious inflammatory absorption around the implant.After 2 months,CBCT result shows that the alveolar bone in the implantation area remained intact.Conclusion: The HA/PLA composite scaffold material was prepared successfully by solution blending method.And the physical and chemical properties,mechanical properties and biological compatibility of materials were improved to some extent.With good physical and chemical properties,mechanical properties and biocompatibility,it can meet the material requirements of medical dental implant material.Rapid prototyping and manufacturing of personalized root implants of rabbit can be achieved by 3D printing technology,which has a broad application prospect in the field of dental clinical.