[Evaluation of osseointegration of domestic porous tantalum-niobium alloy].

Purpose: To evaluate the osseointegration of domestic porous tantalum-niobium(PTa-Nb) alloy.
Methods: A total of 36 adult New Zealand rabbits were selected and divided into 3 groups. Pta-Nb rods(3.5 mm×10 mm) were implanted into the femoral condyle of each rabbit.The rabbits were sacrificed successively at 4,8,12 weeks after operation. X-ray, hard tissue slices stained with toluidine blue, scanning electron microscope(SEM), X-ray energy disperse spectroscopy(XEDS) and push-out test were used to test the osseointegration of PTa-Nb. SPSS19.0 software package was used for statistical analysis.
Results: X-ray films showed no obvious inflammation,as well as implants loosing and bone resorption. Density of the bone around implants increased. Hard tissue slices displayed chimeric shape in the implant-bone interface. New bone contacted directly to the surface of PTa-Nb and got more and more closer with the increase of healing time. Osteoid formed in the inner pores at 4 weeks after operation,and more mature bone tissue grew into inner part of PTa-Nb at 12 weeks. SEM showed bone tissue was more denser and closer to the Pta-Nb,which was similar to the results of hard tissue slices. XEDS analysis showed the percent content of the calcium and phosphate of the tissue within PTa-Nb increased gradually in the three groups.The ratio of Ca/P at 8 and 12 weeks was significantly higher than at 4 weeks (P<0.05); Push-out test showed the shear-strength of PTa-Nb implants increased from (8.26±0.75) MPa at 4 weeks to (21.04±1.46) MPa at 12 weeks (P<0.05).
Conclusions: The domestic PTa-Nb alloy has good osseointegration with both bone tissue ongrowth and ingrowth,which may be a high potential biomimetic bone material.