Research On Bioactivity Of Interconnected Porous Titanium And Ageing Resistance Of Zirconia

The clinical application of arthroplasty has a history of 100 years and Modern Arthroplasty developed by Charnley has been applied for about 50 years. However, some difficulties have not yet been solved, aseptic loosening is one of the difficulties. The reasons for aseptic loosening, especially long-term loosening are mainly wear debris and the weakness of the interface between host-bone and prosthesis. Focused on the above two problems, the present peoject carried out two researches: 1. To research on the bioactivity of the three dimensions interconnected porous titanium(TDIPT) which applied with coatings on prosthesis and improve the strength of the interface of hostbone-prosthesis; 2. To research on the ageing resistance of Zirconia which used to fabricate the artificial femoral head, prevent wear debris of the joint surface and decrease the loosening rate at long-term.Found the optimal measurement to improve the bioactivity of TDIPT. After pretreatment with NaOH solution, the TDIPT was dipped in the 1.5 simulated body fluid (1.5SBF). 14days later, the TDIPT is coated with bonelike apatite layer being formed on its surface, which can improve the surface bioactivity of the TDIPT. The osteoblasts can adhere, proliferate and grow on the bonelike apatite layer.The osteoblasts are seeded on the TDIPT coated with the bonelike apatite layer and cultured in vitro. The result indicates that osteoblasts can adhere, proliferate and grow on the TDIPT, and the TDIPT has excellent biocompatibility and cell affinity. Coating with the bonelike apatite on the surface of the TDIPT improve the its bioactivity and benefits the osteoblasts adhesion and proliferation on the surface of the TDIPT.Bone marrow mesenchymal stem cells(BMSCs) are seeded onto the TDIPTcoated with the bonelike apatite layer, cultured in vitro for two weeks, and then implanted into the rabbit back muscle. The results indicate that new bones are formed in the TDIPT. This imply that the BMSCs can convert to the osteoblast in the TDIPT coated with the bonelike apatite layer and further induces bone formation in vivo.Fabricate a new type of zirconia by adding 5wt% alumina as anti-ageing agent to zirconia. Ageing experiments are carried out by placing the new zirconia sample into a boiler and braise it at 132℃ with two bars pressure up to 30 hours. The results indicate that the degradation of the properties of zirconia is the least after ageing treatment. This benefits the reduction of the wear debris and prolong the lifetime of the prosthesis.