The Research On Surface Modification Of Titanium By Zn-ion Implantation

Objective and background：Titanium and titanium alloy are widely used as common artificial replacementmaterials in clinical surgery and dentistry.Titanium and titanium alloy are widely used as common artificial replacementmaterials in clinical surgery and dentistry. Although, there are numbers of researchesshowing that titanium has good mechanical property, surface characteristic, andbio-compatibility[1]. However, the untreated titanium doesn’t have any biologicalactivity as a biological inert material, it is easy to be infected, and can not get theantibacterial at the same time. As the research showed, the peri-implantitis which iscaused by the bacterial around the implant, will lead the bonding interface losingbetween the implant and bone at the last. The implants will loose and drop[2~3].Porphyromonas gingivalis (P. gingivalis) is the main pathogenic bacterium ofperi-implantitis. The surface modification of titanium implant has certain antibacterialproperties, and reduce the adherence of dental plaque in titanium implant, which playsan important role in the further success rate. Nowadays, the surface treatments ofplasma immersion ion implantation (PIII) technology have been applied to biomedicalmaterials surface as the nano-modification method. On the other hand, Zinc as one ofthe indispensable element in the tissues and organs, can improve the retentionintensity and osseointegration ability of the implant[4]. Meanwhile, Zinc oxide (ZnO) has a certain antibacterial properties[5].This research takes the surface treatments of plasma immersion ion implantationand deposition(PIII) technology, with different ion implantation times, the sampleswere performed using the same radio frequency plasma source. Through the cultivateof mice preosteoblast and P. gingivalis, observe the material surface transformation ofadherency and proliferation after ion implantation, study the effective on osteocyteand P. gingivalis from the zinc ion modified layer in titanium surface, which canprovide experiment evidence for studying the biocompatibility and antibacterialproperties.Method:Ⅰ. The method of pure titanium surface treatmentThe commerce pure titanium were processed into10mm diameter and1mmthickness, with the surface treatments of plasma immersion ion implantation anddeposition(PIII) technology.Ⅱ. The chemical constitution and physical morphology analysis of modifiedlayerX-ray photoelectron spectrometer (XPS), Scanning electron microscopeand (SEM)and Atomic force microscope (AFM) were used to analyze chemical composition andsurface topography of Ti specimens, respectively.Ⅲ. The antibacterial activity of the titanium surface modified by Zn-ionimplantationPorphyromonas gingivalis (P. g) were seeded onto the modified Ti surfaces for48h and observed by SEM. Ⅳ. The effective of zinc ion implantation modified titanium surface onosteogenesis proliferation and adherency1. MTT experimentTest the effective of proliferation of murine osteoblasts through MTT experiment.2. Scanning electron microscopeUtilize the scanning electron microscope to observe the adhesion and morphologyof osteoblast on material surface.3. Acridine orange fluorescent stainingCo-culture the cell on the surface of samples, the attachment and proliferation ofmurine osteoblasts on Zn-PIII Ti surface were studied by Acridine orange fluorescentstaining.Result:Ⅰ. The microanalysis of Zn ion implantation titanium modified material1. Chemical constitution of modified layerAnalysis the result of XPS test, after zinc ion implanted, the Zn singles weredetected on Zn-PIII-treated Ti surfaces with an increase in Zn-implantation time.2. Scanning electron microscopeAfter the Zn-ion implantation, a lot of sporadic granular substance formed on thematerial surface. With the extension of Zn-ion implantation time, the number ofgranular substance is increasing gradually.3．Atomic force microscopy Observe the titanium surface after Zn-ion implantation by atomic forcemicroscopy, the surface roughness is enlarging with the increasing of implantationtime, including the mean roughness and Root Mean Square Roughness.Ⅱ. The antibacterial activity of the modified surface by Zn-ion implantedtitaniumThe effective on P. g adhesion and mycelial morphology after Zn ion implantationtitanium surfaceⅢ. The effective of modified titanium surface by Zn-ion implantation onproliferation and adhesion of osteoblast1. MTT experimentThe number of osteoblast cells(MC3T3-E1) proliferation on the surface ofZinc-ion implanted Ti were significantly more than the control group.2. The cellular morphology by scanning electron microscopeThe osteoblast cells on CP-Ti has the better extensibility than the control group.The adhesion proportion and quantity also have been increased to some extent. Thereare pseudopod formed and well traffic among cells.3. Observe the cell adhesion and proliferation by acridine orange fluorescent stainingThe number of MC3T3-E1adhered on material surface is increasing with theincreasing time of Zn-impalnted. After cultivate24hours, the number of MC3T3-E1on Zn ion implantation titanium group is obviously higher than the control group, andthere is statistical significance (P<0.05).Conclusion: 1. After Zn-ion implanted on titanium surface, the elements of Zn-PIII Ti surface aremainly titanium (Ti), oxygen (O) and zinc (Zn). The surface zinc content reached themaximum when implantation time was90min. After the ion implantation, there are alot of dispersed lumps formed on the surfaces of titanium, and the quantity anddistribution of pore structure reaches the peak at90min of the implantation time.2. The modified titanium surface after zinc ion implantation could restrain theadhesion and growth of P. gingivalis, and effect the mycelial morphology. Theinhibiting effect reaches the peak at90min of the implantation time.3. The modified material of zinc ion implantation is no cytotoxicity for miceosteogenesis cells MC3T3-E1. The pure titanium after zinc ion implantation canimprove the adhesion and proliferation of MC3T3-E1.