Preparation Of Porous Zirconia Implant And Its Osteogenic Effect

Zirconia ceramic is an ideal repair material because of its good biocompatibility,mechanical properties and so on.However,the surface treatment of zirconia implants is still limited,the traditional blasting will introduce cracks and increase the fractured risk of zirconia implants.How to roughen the surface of implant and increase the degree and speed of osseointegration is still an urgent problem to be solved.In this topic,the zirconia coating was coated on the surface of the zirconia blank,and the porous surface was formed after high temperature sintering without external introduction of cracks.The effect on the osteoblast was studied.The present study includes two parts.One is the effect of the surface physical and chemical properties of zirconia implants after porous treatment.The other is the effect of the surface biological properties of zirconia implants after porous treatment.Objective: one is to study the surface morphology,elemental composition and surface roughness of zirconia implant after porous treatment.The other is the effect of the surface biological properties of zirconia implants after porous treatment.Materials and methods: Yttrium oxide stabilized porous zirconia ceramics were prepared by diameter 15 mm and thickness 1.5mm.The control group were the same size zirconia porcelain without treatment of porous and pure titanium plate.The control group were polished by 400 mesh,600 mesh and 800 mesh water sandpaper,cleaned ultrasonically by absolute alcohol with 10 minutes and disinfected under high temperature(121.3 ?)and high pressure(103.43 k Pa)with 30 minutes.Using the following methods to test the pure titanium plate,the zirconia ceramics with and without porous processing: one is surface physical and chemical performance test.We can use the scanning electron microscope and energy dispersive spectrometer to test the surface morphology and surface composition of the pure titanium plate,the zirconia ceramics with and without porous processing.We can use the white light interferometric microscopy and contact instrument for roughness to test the 3D surface topography and surface roughness of the three kinds of samples.The other is biological test.We can put 30 films of pure titanium,30 films of untreated zirconia ceramics and 30 films of porous zirconia ceramic in the 24 hole plate and we should put 40 thousand MC3T3-E1 mouse osteoblasts in each hole.We can culture cells with ordinary culture medium and differential medium after three days.And then,we should stop culturing on the third and seventh day,and then they are used to extract total RNA of each hole,reverse transcription into c DNA,and detect by the real-time fluorescence quantitative q PCR method for determining the gene relative expression of ALP,OCN,OPN,RUNX2,SATB2.After inoculating the cells in some samples,we should discard the culture medium,rinsing 3 times by PBS,fixing by 2.5% glutaraldehyde,and dehydrating in graded ethanol,we can measure the morphology of cells by scanning electron microscopy in the third days and seventh days.Similarly,after inoculating the cells in some samples,we should discard the culture medium,rinse 2 times by PBS,stain by MTT and dissolve in isopropanol.And then,we can measure the OD value by enzyme-linked immunoassay instrument.Results: Firstly,porous zirconia ceramic surface is about 1~20 micron size of pore structure and the surface roughness is 0.57?m which is similar to pure titanium with the surface roughness of 0.50?m,but it is much larger than untreated zirconia with the surface roughness of 0.20?m.Secondly,the real time fluorescence q PCR showed that pure titanium group and untreated zirconia group have similar gene expression trend of osteoblast about ALP,OCN,OPN,RUNX2,SATB2.And the porous zirconia ceramic's gene expression of osteoblast increases significantly as time increases,which is significantly higher than that without surface treatment of zirconia implant,and the difference is statistically significant.Cell morphology showed that there was no significant difference in cell morphology between the three groups,and they have similar cell attachment,but the porous zirconia group had higher cell proliferation ability.Conclusion: Firstly,the zirconia ceramics and pure titanium have similar osteoblast behavior.Secondly,porous surface treatment technology can promote the osseointegration of zirconia implant.