Study Of Titanium Surface Modified By Laser Cladding

Objective This work focuses on the titanium surface with porous structure，obtained bylaser cladding of titanium powder with a particle size of45μm on titanium surface in anargon atmosphere. The available binder and the best parameters would to be determinedto construct porous titanium surface with interconnected holes. Surface appearance,microstructure, composition were performed by Sacnning Electron Microscopy(SEM）and Energy Dispersion Spectroscopy(EDS). and cell compatibility were evaluated byBone marrow stromal stem cells （BMSCs）culture in vitro. This study is expected toprove that porous titanium surface is more suitable for cell adhesion, proliferation anddifferentiation.Methods The specimens were prepared by a pulsed Nd:YAG laser cladding procedureon preset titanium powders. In this study the most available binder and the bestparameters were determined. The microstructure and chemical composition analyseswere performed by Sacnning Electron Microscopy(SEM）and Energy DispersionSpectroscopy(EDS). Contral group A(titanium disks with smooth surface), Contralgroup B(laser irradiated titanium disks) and Experiment group C (laser meltingmodified titanium disks) were examined. BMSCs were cultivated on the titaniumdisks,titanium disks were removed，fixed in2.5%Glutaraldehyde，rinse by PBS,sprayed gold and examined with SEM.CCK-8method and alkaline phosphatase activitydetection were taken to evaluate the effect of such modify on the proliferation anddifferentiation of BMSCs. Results Using laser melting with the pulsed laser, the best parameters were found to be:current of110A, laser peak power of2.2kW。The surface microstructure consisted ofmultilevel and interconnected holes that size range from100nm to20μm。Na2SiO3·9H2O was found to be the available one among the five kinds of binders，whose spectrum displayed that titanium element and inorganic-Silicon elementexsisted。The BMSCs cultivated on group C presented a higher cellular density incomparison to two other groups. In thin study fiber mesh was formed in the holes ofgroup C。 Titanium surface modified by laser melting proved of good cellbiocompatibility and may promote adhesion， proliferation and differentiation ofBMSCs。Conclusions The formed microstructure consisted of multilevel and interconnectedholes，surface contact area was increased。The surface of three dimensional holes hadmore growth space to promote cell adhesion, proliferation and differentiation.Inorganic-Silicon element was found in group C, which indicated that titanium surfacecan be considered to add biological activity materials to increase bone osseointegration.Laser cladding of titanium surface proved to be an efficient and environmentally way tomodify implant surface, with the develpment of Rapid Prototyping（RP）, Laser RapidPrototyping(LRP) is expected to have broad application prospects in implant field.