ABSTRACT
Variation in pH value of oral cavity circumstance causes decayed tooth. In this paper, corrosions of Ti-Fe-Mo-Mn-Nb-Zr dental alloys in various pH lactic acids were studied by immersion test. In the case of pH=4, which is an acidity slightly larger than that causes decayed tooth, Ti-Fe-Mo-Mn-Nb-Zr alloys are entirely corrosion-resistant, and the corrosion type is pitting. With the increase in acidity, the corrosion-resistance of Ti-Fe-Mo-Mn-Nb-Zr alloys deteriorates, and the corrosion type changes from pitting to intergranular corrosion. Fe ion is the most dissolved substance in impregnation, which means Fe goes against the corrosion-resistance of Ti alloys. Both results of thermodynamics calculation and X-ray photoelectron spectroscopy have shown that Mn2O3, Nb2O5 and TiO2 form oxide film on the surface of Ti-Fe-Mo-Mn-Nb-Zr alloys.
Subject(s)
Humans , Corrosion , Dental Alloys , Chemistry , Hydrogen-Ion Concentration , Iron , Chemistry , Lactic Acid , Chemistry , Manganese , Chemistry , Molybdenum , Chemistry , Niobium , Chemistry , Surface Properties , Titanium , Chemistry , Zirconium , ChemistryABSTRACT
The influences of Ce on the microstructure and mechanics performances of Ti-Fe-Mo-Mn-Nb-Zr alloys were studied and presented in this paper. The microstructure of no-Ce Ti-Fe-Mo-Mn-Nb-Zr alloy was thick, long and dendritic, and the microstructure of alloy was fined by Ce. With the increase in Ce wt%, the microstructure became equiaxial gradually. Hardness decreased with the increase in Ce wt%. The compression yield strength became greater with the increasing of Ce wt%, but after the Ce wt% increased to a certian degree, the compression yield strength became smaller with the further increasing of Ce wt%. This phenomenon was explained in the light of bond energy and X-ray diffraction experiment. X-ray diffraction experiment showed that the alloys were beta-Ti.
Subject(s)
Alloys , Chemistry , Biocompatible Materials , Cerium , Chemistry , Hardness , Materials Testing , Surface Properties , Titanium , ChemistryABSTRACT
In this study, the general toxicity tests including acute toxicity test, haemolysis test, MTT assay of Ti-Fe-Mo-Mn-Nb-Zr alloys were carried out. The morphology of these cells was also observed under phase-contrast microscope. By using X-ray photoelectron spectroscopy(XPS), the kind and mol% of element in surface film were studied. The kind and concentration of element in dipping fluid were investigated by ICP atomic emission spectrometry. The results showed the primary component is TiO2 in surface film. The dipping fluid of Ti-Fe-Mo-Mn-Nb-Zr alloys contains Fe 0.2-1.07 mg/l and Mn 0.16-0.5 mg/l; such dental materials are beneficial to health. No cytotoxic effect was disclosed by in vitro and in vivo tests. The level of cytotoxicity was grade 0 and 1; the haemolysis degree was 0.558%-0.642%, i.e. less than 5%. The cells growing in the extract showed normal morphology. These data indicate that Ti-Fe-Mo-Mn-Nb-Zr alloy, as a dental material, has good biocompatibility.