دانلود گزارش کارورزی و کار آموزی

چکیده : 

The majority of titanium based bone-level dental implants available on the market today feature a

sand-blasted and acid-etched (SBAE) surface that contains comparably high hydrogen levels. Cathodic

polarization of titanium in acidic solutions is known to further increase titanium hydride on the

surface. The aim of this study was to explore the effect of cathodic reduction on titanium (Ti) and

titanium–zirconium (TiZr) with a SBAE surface in order to investigate the potential of such a process for

further improving surfaces for bone anchored dental implants. Samples of both materials were cathodically

polarized in acidic solution at different current densities and for different process times. Chemical

analysis of the hydrogen levels by SIMS showed that cathodic reduction re-arranged the hydride already

present on the surfaces from the etching process but could not significantly increase hydride levels. The

hydrogen layer created by the preceding hot acid etching appeared to modulate further hydride creation.

Analysis of the surface topography by SEM showed changes to the nano-topography of both materials

after polarization. TiZr showed homogeneously distributed nano-spheres as they were already observed

for TiZr SBAE at increased size of 80–100 nm on the whole surface. By contrast, polarization of Ti created

nano-nodules and nano-spheres of 150–200 nm on the surface. These spheres were interconnected to

form flower-like structures along the ridges and peaks of the surface. Moreover the flanks were covered

by a rippled structure of isotropically distributed small-diameter (10–20 nm) nano-nodules.