The Study Of Selective Laser Melting 3D Printing Titanium Implant And Its Osteogenesis Performance

BackgroundDental implants are routinely used in clinical dentistry to restore missing teeth and avoid disuse atrophy to the alveolar bone.Implants can also help to preserve the adjacent teeth and can achieve an unparalleled functional and aesthetic effect.A customized implant can also simulate the mechanical properties between the anatomical root and the alveolar bone.3D-printed titanium implants have good clinical applicability in alveolar bone repair as they can be shaped to suit any defect type.Suitable surface treatments have the potential to improve the biocompatibility and osseointegration of implants,which in turn would enhance the time to loading and the recovery of normal activities of daily living.ObjectiveThe study aims to prepare titanium implants by selective laser melting(SLM)and improve the biocompatibility and osseointegration of implants with suitable surface treatments.To analysis of the SLM printing titanium implant samples'biocompatibility with surface characterization and in vitro cell experiment,to improve the biocompatibility and osseointegration of implant samples.To in vivo animal experiments to provide theoretical and experimental basis for what making 3D printing implant can be eventually used in clinical therapy.MethodSLM printing titanium implant wafer specimens 60 pieces,sandblasting polishing,5%hydrofluoric acid pickling and then ultrasonic cleaning,drying in fluid N2,20 pieces are selected randomly as the group S;The remaining 40 specimens are treated by anodic oxidation(AO)for 30 min,flushing by deionized water,heat treatment at 500?for 3h,which randomly selected 20 pieces as the group SA;Confecting rhBMP-2 solution of 0.1%concentration as the surface modification solution,the remaining 20 specimens ultrasonic shock soaked in the solution for 10s as the group SAB;Field emission scanning electron microscopy(FE-SEM)and atomic force microscope(AFM)are used to observe the surface topography and roughness of each specimen.Contact angle measurement measure the hydrophilic;Bone marrow mesenchymal stem cells(BMMSCs)were seeded onto the surface of specimens,spraying gold,SEM observe the adhesion of BMMSCs;CCK-8 was used to detect the proliferation of the BMMSCs at the surface of each group.The effects of SLM 3D printed titanium implants on the osteogenic capacity of bone were verified by in vivo animal experiment.Micro-CT scan,three-dimensional reconstruction and bone tissue measurement of implant-bone tissue interface of new bone formation and bone union;Tissue sections fluorescence markers and methylene blue-acid magenta solution staining implant-bone tissue interface,histological observation of implant-bone interface.Statistical analysis:SPSS 22.0 software was used to statistically analyze the data obtained from this study.One-way ANOVA was used to compare the differences among groups,test the homogeneity of variance.Use the LSD test to compare the mean of the samples if the variance was regular.Use the correction Welch method if not.The two-sided test was considered statistically significant when P<0.05.ResultSuccessfully prepared SLM 3D printing titanium implant samples;A layer of uniform titania nanotubes was successfully prepared on the surface of titanium substrate about 100 nanometers in diameter by the anodic oxidation method;Using physical adsorption method in the titanium dioxide nanotube surface load bone morphogenetic,the protein was simple and easy to be loaded and was effectively loaded by the amount released in the simulated body fluid.The surface of Ti02 nanotubes showed superhydrophilicity with suitable roughness and surface free energy.The anodic oxidation load with rhBMP-2 modification can effectively promote the adhesion and proliferation of BMMSCs;Bone tissue measurement analysis showed that the bone volume fraction,bone mineralization density and planting density.The rate of osseointegration was significantly increased in all experimental groups than in control group.Compared with the other groups,the anodic oxidation load with rhBMP-2 modified group showed obvious advantages.ConclusionThe use of SLM printing of titanium implant samples loaded with bone morphogenetic protein on the basis of anodizing have biocompatible properties and more in line with the dental implant surface characteristics.Titanium dioxide nanotube surface suitable micro-nano-scale roughness,anatase titanium dioxide showed super-hydrophilic properties;The anodic oxidation load with rhBMP-2 modified can effectively promote BMMSCs adhesion and proliferation on SLM printing samples surface.SLM printing samples with surface treat could promote new bone formation and shorten bone healing time.