Study On Low-temperature Deposition Manufacturing And Mandible3d Reconstruction

Mandible is not only closely related to appearance, but also undertake chewingfunction with maxilla together, in addition, it plays an important role in keeping theairway unblocked, therefore, the treatment of mandibular defect has been a concernfor long time. Recently clinical methods such as autogenous bone graft, distractionosteogenesis, etc., although each of them possesses their advantages, there are manydefects such as bone resorption and long cycle surgery, especially patients can not bepersonalized repaired according to the complexity and size of people’s injuries. Withthe development of bone tissue engineering and rapid prototyping technology, it’s anew method to use appropriate technology to personalized repair bone defects bypreparing scaffold. In this paper, we used3d reconstruction software Mimics10.01toreconstruct the model3d of mandible, then we used finite element analysis technologysoftware Ansys14.5to analyze the3d model of mandible. We made a seriesoptimization of bone scaffold preparation conditions, and evaluated thebiocompatibility of bone bone scaffold. On this basis, we selected the best materialratio evaluated by this paper’s experiments, through Low-temperature DepositionManufacturing (LDM) to make part of mandible bone scaffold, to provide newmethod of personalized repairing mandible defects.In this paper, we selected polylactic acid-glycolic acid (PLGA) as the matrix,composite with pearl powder or tricalcium phosphate (TCP), we used SolidWorks andAurora to build bone scaffold digital models, then we manufactured various materialproportions of scaffolds by LDM: PLGA: pearl powder or TCP=10:0,5:2,7:3,6:4,dissolved in1,4-dioxane, which PLGA and1,4-dioxane mixed in proportion3g/20mL.The LDM manufacture, hydrophilic, degradation, porosity, SEM surface morphologyand compressive mechanical properties, all of them gave a comprehensive evaluation.The results showed that the pure PLGA scaffold had the best porosity (83.33%) andthe easiest controlling of LDM. PLGA: pearl powder or TCP=5:2groups had the bestcomprehensive evaluation: continuous macroporous structure and uniform porestructure (porosity of82.54%or82.06%), the contact angle of the scaffold reducedfrom87.64°to77.98°or81.73°, suitable degradation rate (14days degradation is40.23%or40.77%), and the pH of degradation products was closed to normal physiological conditions. In addition, the composite material scaffold possessed bettercompression elastic modulus (36.097MPa or32.933MPa). These results indicated thatscaffold composite with pearl powder or TCP can improve the comprehensiveperformance of scaffold, scaffold composited with pearl powder or TCP can meet therequirements of bone tissue engineering scaffolds betterly.In this paper, we evaluated scaffolds’biocompatibility. We prepared four kinds ofscaffolds by LDM: pure PLGA non-porous scaffolds, pure PLGA and PLGA: pearlpowder or TCP=5:2porous scaffolds. We inoculated the MC3T3-E1mouse osteoblastson sterilization scaffolds, and cultured1h,3h, usig flow cytometry cell to detectadhesion rate. We detected the proliferation cells cultured for1,4and7days by theAlamar Blue. We used JC-1mitochondrial membrane potential marker to detectMC3T3-E1cells mitochondrial function on different scaffolds. These experimentalresults showed that a porous scaffold structure and pearl powder or TCP materialswere all promoting cell adhesion and proliferation: pure PLGA porous scaffolds getbetter attachment and proliferation than nonporous group by43.76%~7.66%and5.39%~9.01%; increased by9.48%~1.21%and18.69%~23.17%compared with purePLGA scaffolds; and surface mitochondrial membrane potential were significantlyhigher than those of pure PLGA group, results indicated that the cell on scaffoldsurface had a better energy metabolism, composition with pearl powder or TCP wasvery beneficial for cell function.Finally, we used Mimics10.01to reconstruct mandible3D model, surface meshing,and we used Ansys14.5to finite element analysis, then we summarized the stress ofmandible. We used Mimics10.01segmentation, select part of the mandible bone tostudy, we used Mimics10.01and Aurora to build optimized scan path, selected PLGA:pearl=5:2ratio as slurry to1:1prepare mandible bone scaffold by LDM, which sizeand shape were the same with the real of part mandible bone, the mandible bonescaffold possessed a stronger compressive elasticity modulus (25.90MPa) than thesame size scaffold (24.45MPa).