Due to good properties, which meet the requirements for use as biomaterials, titanium and titanium alloys have been increasingly used as dental implants. Until recently, dental titanium alloys were produced by casting. Since this process does not meet the terms of economy and efficiency, the production of titanium implants by powder metallurgy are very promising. Therefore, in this work titanium alloy with addition of 10 at. % zirconium is prepared by powder metallurgy with the goal of obtaining the best producing conditions, which would result in the titanium alloy of the adequate properties for use as dental implants. High values of green densities were achieved even only by uniaxial pressing. Further, sintering temperature of 1673 K resulted in the alloy of the highest sintered density and microhardness. The results of this investigation revealed the processing parameters applicable for the production of titanium-zirconium dental implants by powder metallurgy.
This study presents the results of light optical and scanning electron microscopy as well as energy dispersive spectroscopy investigation of the Ni-based self-fluxing alloys (NiCrBSi, NiCrWBSi and NiCrBSi + WC) deposited on steel substrates (heat treated carbon steel C45, heat treated low-alloyed steel 42CrMo4 and austenitic stainless steel X6CrNiMo18-10-2) by one-step flame spraying and fusing process. The microstructure of coatings and coating/substrate interface but also the effects of deposition technology on the heat-treated steel substrates which have frequently been used in practice were investigated. The influence of the sample size on the microstructure was also discussed. A proof is given of the change in the structure of coating, coating/substrate interface and substrate due to high fusing temperature, depending on type of steel substrate (and relating thermal properties), coating thickness but also on dimensions of the sample.
Lithium disilicate and zirconia are the two most popular materials for aesthetic and dental prosthetic work; however, due to their limitations, a new material is being researched, namely zirconia-reinforced lithium disilicate, the surface of which is treated with different procedures to achieve the best possible surface properties. In this study, the surface of zirconia-reinforced lithium disilicate glass-ceramic was treated using different methods (conventional and laser) to determine the effects of the treatment procedures on the surface properties and surface roughness to achieve a higher strength of adhesion from the self-adhesive resin cement to zirconia-reinforced lithium disilicate. The treated surfaces were investigated using profilometry, X-ray diffraction and energy dispersive X-ray fluorescence. The results obtained were statistically evaluated. The results show that the surface roughness is highest for the samples treated with Er:YAG (erbium-doped yttrium aluminium garnet laser) and silanisation. Furthermore, the surface treatment procedures applied did not change the composition of the surface.
Cobalt–chromium alloys (Co-Cr) are widely used in dentistry due to their excellent mechanical properties and corrosion resistance. Since prosthetic materials must be permanently stable in the oral cavity, it is very important to determine the release of ions from alloys in the oral cavity. In dentistry today, metals and alloys are mainly joined by laser and tungsten inert gas (TIG) welding. Therefore, in this work, the release of metal ions from six different Co-Cr alloys joined by these two welding methods was quantified to determine the effects of the welding method on an ion release. Static immersion tests, atomic absorption spectrometry and statistical analysis were performed for this purpose. The results showed that laser-welded alloys release a lower amount of metal ions compared to TIG-welded alloys.