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Abstract Veneering ceramics should be strongly bonded to zirconia core in order to achieve successfully long-term clinical practice. Indeed, to pursue the high zirconia core–veneering ceramic bonding is still a concerned issue. In this regard, this study was to treat zirconia surface using a 3 wt% Si 3 N 4 solution in 4 M NaOH and to investigate the effect of soaking time (5, 10, and 20 days) on the surface properties of zirconia and shear bond strength between zirconia and veneering ceramics. The residual veneering ceramics on zirconia surfaces and failure modes were also examined after fracture. The results showed that the phase composition of zirconia before and after surface modification was not changed. The elemental mapping and depth profiling consistently revealed the soaking-time-dependent Si content on the zirconia surface. The surface roughness of zirconia was significantly (P < 0.05) increased with the increasing soaking time. When zirconia was treated for 10 days, the shear bond strength value of 27.4 MPa was significantly (P < 0.05) higher than the control (18.6 MPa), associated with greater remaining amounts of veneering ceramics on the zirconia surface. The failure mode of the treated zirconia was almost the mixed failure. On the basis of the data, surface modification using Si 3 N 4 in NaOH solution for zirconia core could be a simple and effective method for enhancing the veneering ceramic–zirconia bonding. [ABSTRACT FROM AUTHOR]

Abstract Knowledge of an exact value of the relative detection factor (RDF) is important for correct quantification of measurements of Secondary Neutral Mass Spectrometry (SNMS). A special crystal ingot was grown from the vapor phase to determine this coefficient for PbTe binary telluride. Sputtering of the samples was carried out by Ar+ ions with energy of 350 eV. High structural quality of the crystal grown from vapor phase allowed minimizing the density of the surface structures forming on the sputtered surface and the dimple relief of the surface. The magnitude of RDF is determined and the analytical expression is given for its energy dependence, taking into account correction caused by the impact of the transmission factors which determine the fractions of emitted Pb and Te atoms collected into the mass spectrometer. Highlights • High quality PbTe crystal was growth from vapor phase and sputtered by Ar ions. • The magnitude of relative detection factor was determined for PbTe binary telluride. • An analytical expression is given for energy dependence of relative detection factor. [ABSTRACT FROM AUTHOR]

[Display omitted] • Annealing at 750 °C significantly improved the adhesive strength of the CaSi coating. • CaSi coating enhanced the osteogenic differentiation of hMSCs. • CaSi coating reduced E. coli and S. aureus bacterial adhesion and growth. To ensure clinical success, the implant and the surrounding bone tissue must not only be integrated, but also must not be suspected of infection. In this work, an antibacterial and bioactive nanostructured calcium silicate (CaSi) layer on titanium substrate by an electrospray deposition method was prepared, followed by annealing at 700, 750 and 800 °C to improve the bonding strength of the CaSi coating. The phase composition, microstructure and bonding strength of the CaSi coatings were examined. Human mesenchymal stem cells (hMSCs), Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) species were used to analyze the osteogenic and antibacterial activity of the coatings, respectively. Experimental results showed that the as-prepared CaSi coating was mainly composted of β-dicalcium silicate phase with a particle size of about 300 nm. After annealing, the thickness of the oxidation reaction layer increased obviously from 0.3 μm to 1 μm with increase in temperature, which was confirmed by the cross-sectional morphology and element depth profile. The bonding strength of the coating annealed at 750 °C (19.0 MPa) was significantly higher (p < 0.05) than that of the as-prepared coating (4.4 MPa) and the ISO 13,779 standard (15 MPa). The results of antibacterial efficacy and stem cell osteogenesis consistently elaborated that the 750 °C-annealed coating had higher activity than the as-prepared coating and the Ti control. It is concluded that after annealing at 750 °C, the CaSi nanoparticle-coated Ti implant had good bond strength, osteogenic and antibacterial activity. [ABSTRACT FROM AUTHOR]