Different Porosity Titanium Implants Effect The Function Of Osteoblast Cells In Vitro

Objective:This study investigated the effects of porosity of porous titanium implants on adhesion,proliferation and differentiation of osteoblast cells after surface modification in vitro.Material and method:Firstly this study utilized the metal injection molding to prepare porous titanium implants with porosity of 5%,30%,40%,50%,60%;secondly carried out the surface modification by means of acid-base heat treatment,biomimetic deposition hydroxyapatite;thirdly conducted the toxicity experiment by MTT method on the rat fibroblast cells L929;lastly assessed the influence of different porosity porous titanium implant on adhesion,proliferation and differentiation of osteoblast cells MG63 in vitro.Result:The MTT test showed the leaching liquor with 100%,50%,10% concentrations of porous titanium was nontoxic to L929;Taking count of the result by light microscope after the porous titanium implanst cultured with MG63 for 4 and 8 days,it showed the amount of cells was no significant difference between 5%and 30%group(P＞0.05).But it increased with the other three groups,and the difference was remarkable(P＜0.05);SEM showed: MG63 was flat on the surface of 5%porosity titanium implant and extended to amphi-edge of the pore on the surface of 30%porosity titanium implant. Several pseudopodias adhered to the edge of the pore on the surface of 40% porosity titanium implant.Especially the titanium implants with porosity of 50%and 60%could be clearly noticed that the pseudopodias adhered deeply to the hole wall,formed the cell bridges,and the cells could ingrowth into the pores;After cultured 8 days,the ALP content was no significant difference between 5%and 30%group(P＞0.05).But there was significant(P＜0.05) between the other group.No difference in OCN production was detected on 5%and 30%group(P＞0.05).But the difference was remarkable(P＜0.05)on the other three groups.Conclusion:It was successfully to prepare the porous titanium implant with different porosity and interconnected pores by MIM technology,which are nontoxic to fibroblast cells in vitro after the surface modification by acid-base heat treatment and deposition HA.It is propitious to osteoblast cell's adhesion,proliferation and differentiation with the increase of porosity.