MgO-doped tantalum coating on Ti: microstructural study and biocompatibility evaluation

Abstract

Pure and MgO incorporated Ta coatings were prepared on Cp-Ti substrate using laser engineered net shaping (LENS), which resulted in diffuse coating-substrate interface. MgO was found along the Ta grain boundaries in the Ta matrix that increased the coating hardness from 185 ± 2.7 HV to 794 ± 93 HV. In vitro biocompatibility study showed excellent early cellular attachment and later stage proliferation in MgO incorporated coatings. The results indicated that although Ta coatings had higher biocompatibility than Ti, it could further be improved by incorporating MgO in the coating, while simultaneously improving the mechanical properties.

Figure 1

Cross-sectional SEM microstructures of MgO coated Ta coatings processed at 400 W (a) 10 mm/s, (b–d) 15 mm/s.

Figure 2

X-ray diffraction results of MgO coatings on Ta processed at 400 W and 15 mm/s.

Figure 3

Optical density measurement illustrating hFOB cell proliferation on HA, Sr-HA, and Mg-HA after 3, 7, and 11 days of culture (*p < 0.05 and **p > 0.05, n = 3).

Figure 4

FE-SEM micrographs illustrating the hFOB cell morphologies after 3 days of culture (a) Ti (b) Ta coatings (c) Ta+ MgO coatings. The spherical objects in (b, indicated by white arrow) are Ta particles and that of (c) are apatite nodules.

Figure 5

FE-SEM micrographs illustrating the hFOB cell morphologies after 7 days of culture (a) Ti (b) Ta coatings (c) Ta+ MgO coatings.