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Fixed prosthodontics is performed in different materials to replace absent dental structures, which can be totally metallic or metallic coated with ceramic, being generally widely used. At present, we have proposals for fixed prostheses with better aesthetic results, such as metal-free prostheses, which allow the professional to reproduce better and in more detail the dental anatomy and in this case also the gingival character. Materials such as zirconia are available that have properties such as biocompatibility, low thermal conductivity, resistance to corrosion, naturalness and aesthetics. In addition, new technological methods are available with which very satisfactory results can be achieved, such as the use of CAD-CAM technology. The present clinical case is focused on the replacement of dental organs and soft tissue, for the rehabilitation of the anterior sector, with materials with favorable characteristics, such as zirconium that contribute to return functionality, phonetics, aesthetics and chewing, through a fixed prosthesis of six metal-free units, with the greatest adaptability to both dental and gingival tissue. The progress of each clinical stage was verified, such as the preparation of the abutments, placement of the provisional, impressions, test of the structure and cementation. [ABSTRACT FROM AUTHOR]

Due to their mechanical properties and bioactivity, zirconium and its alloys are adequate materials for biological applications. Another important characteristic of these materials is the formation of a native oxide layer that limits corrosion, and the consequent release of metal ions to the biological media. However, it is of interest the development of a surface treatment that further limits corrosion and improves the bioactivity. In particular, in previous studies surface modification induced by anodisation has proved to be effective to both objectives, as well as being of easy implementation. In the present work the viability of using anodised Zr-2.5Nb at different potentials between 30 and 120V as implant material, was evaluated. The corrosion susceptibility was investigated through electrochemical tests performed in vitro, and the bioactivity was evaluated as the osseointegration capacity through implant tests performed in vivo. It was found that the anodisation of Zr-2.5% Nb improves its resistance to corrosion, as well as its osseointegration capacity, measured through the percentage of osseointegration. Among the anodising potentials evaluated in the present study, 30V is the optimal one since it yields the highest percentage of osseointegration as well as low corrosion rates. [ABSTRACT FROM AUTHOR]

By using x-ray diffraction, TGA Hi-Res, BET and DSCM techniques the exothermical process around 700 K in ZrO2-x(OH)2x is analyzed. This is associated to the beginning of the gradual transformation of the tetragonal metastable phase at low temperatures to monoclinical phase. The entalphy associated to the process (ΔH=-15,49 kJ/mol of ZrO2) is the result of simultaneous events relative to the reversible (ΔH=0,0161 kJ/mol of water) and no-reversible hot (ΔH=-15,60 kJ/mol of ZrO2), assigned to the broken of the Zr-OH bonds with H2O losses by condensation of OH- groups and liberation of surface free energy with the formation of new Zr-O-Zr bonds, respectively. This interpretation supports the increment of the oxolation and structural units of polications of Zr promoting the transformation to the monoclinical phase. [ABSTRACT FROM AUTHOR]