A Novel Silane Primer System Approach for Resin Zirconia Bonding

Oral Session: Dental Materials 3: Ceramic-based Materials and Cements - 187. Clinical Studies, Surface, Interface, and Bonding: no. 1576OBJECTIVE: To investigate the effect of two cross-linking silanes blended with 3-acryloxypropyltrimethoxysilane on the shear bond strength between resin cement and silica-coated zirconia. MATERIALS AND METHODS: 90 specimens of zirconia (Nobel Biocare) were subjected to silica-coating by Rocatec Plus (3M ESPE, 110 μm) sand at an operation pressure of 280 kPa, for 30 s/cm2. 3M ESPE Sil-silane (3M ESPE) was used as a control. Primers of 1.0 vol% of 3-acryloxypropyltrimethoxysilane (ACPS), with 0.5 vol% cross-linking silanes bis-1,2-(triethoxysilyl) ethane (BTSE; Gelest) and bis[3-(trimethoxysilyl)propyl] amine (BTMA; ABCR) were prepared in a 95% ethanol and 5% deionised-water solvent mixture. The solutions were ...postprin

Shear bond strength between resin and zirconia with two different silane blends

OBJECTIVE: To study in vitro the effect of two cross-linking silanes, bis-1,2-(triethoxysilyl)ethane and bis[3-(trimethoxysilyl)propyl]amine, blended with an organofunctional silane coupling agent, (3-acryloxypropyl)trimethoxysilane, on the shear bond strength between resin-composite cement and silicatized zirconia after dry storage and thermocycling. MATERIALS AND METHODS: Six tested groups of 90 samples of yttria stabilized zirconia were used for sample preparation. The surfaces of the zirconia were silica-coated. 3M ESPE Sil silane was used as a control. Solutions of (3-acryloxypropyl)trimethoxysilane with cross-linking silanes bis-1,2-(triethoxysilyl)ethane and bis[3-(trimethoxysilyl)propyl]amine were applied onto the surface of silicatized zirconia. 3M ESPE RelyX resin-composite cement was bonded onto the silicatized and silanized zirconia surface and light-cured. Three groups were tested under dry condition and the other three groups were tested for thermocycling. The shear bond strength was measured using a materials testing instrument. Group mean shear bond strengths were analysed by ANOVA at a significant level of p < 0.05. The zirconia surface composition was analysed by X-ray Photoelectron Spectroscopy. RESULTS: The highest shear bond strength was 11.8 +/- 3.5 MPa for (3-acryloxypropyl)trimethoxysilane blended with bis-1,2-(triethoxysilyl)ethane (dry storage). There was a significant difference between mean shear bond strength values for (3-acryloxypropyl)trimethoxysilane blended with two cross-linking silanes, bis-1,2-(triethoxysilyl)ethane and bis[3-(trimethoxysilyl)propyl]amine, after thermocycling (p < 3.9 x 10(-8)). Various surface treatments of zirconia influenced the surface roughness (p < 4.6 x 10(-6)). The chemical composition analysis showed there was an increase in silicon and oxygen content after sandblasting. CONCLUSIONS: The results suggest that the combination of functional (3-acryloxypropyl)trimethoxysilane with cross-linking bis[3-(trimethoxysilyl)propyl]amine showed superior hydrolytic stability than with bis-1,2-(triethoxysilyl)ethane.postprin

Soft x-ray ionization induced fragmentation of glycine

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Experimental evidence of a dynamic Jahn-Teller effect in C+60.

Detailed analysis of the highest occupied molecular orbital band shape in the photoelectron spectrum of gaseous C60 reveals a dynamic Jahn-Teller effect in the ground state of C+60. The direct observation of three tunneling states asserts a D3d geometry for the isolated cation, originating from a strong vibronic coupling. These results show that the ionic motion plays an important role in the electron-phonon interaction

Morphological and elemental evaluation of SDF on dentine in saliva

Poster Presentation: Scientific Groups - 24. Mineralized Tissue: no. 172OBJECTIVES: Silver diammine fluoride (SDF) is an effective agent for caries management. Its interaction with saliva is unknown. The aim was to investigate the effect of SDF on dentine with natural and artificial saliva and evaluate different potential saliva solutions. METHODS: 20 dentine samples were randomly assigned into 4 storage groups: deionized water (DIW, negative control), artificial saliva (AS), basal medium mucin (BMM), and unstimulated whole saliva (UWS, clinical reference). After which they were submitted to the demineralization process (50 mM acetate buffer, pH 4.5) for 3 days. 38 wt% SDF (SaforideTM) was then applied ...postprin

Surface modification of silica-coated zirconia by chemical treatments

Zirconia surface modification by various chemical treatments after silica coating by sandblasting was investigated in this study. The surface of silica-coated dental zirconia was hydroxylated by treatment with different acids at room temperature for 4 h, rinsed with deionized water and air-dried. The modified surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Shifts in binding energies for Zr 3d 5/2 and Si 2p peaks were observed after treatment with acids, thereby showing a change in the chemical states of zirconium and silicon on the surface layer of silica-coated zirconia. The XPS analysis revealed that the silica-coated zirconia (SiO2-ZrO2) surfaces had changed to hydrous silica-coated zirconia (SiO2-ZrO2·nH 2O). One-way ANOVA analysis revealed there was significant difference in both surface roughness parameters of silica-coated zirconia after chemical treatments and the surface topography varied depending on the acid treatment. © 2010 Elsevier B.V. All rights reserved.postprin

X-ray Pump-Probe Investigation of Charge and Dissociation Dynamics in Methyl Iodine Molecule

Molecular dynamics is of fundamental interest in natural science research. The capability of investigating molecular dynamics is one of the various motivations for ultrafast optics. We present our investigation of photoionization and nuclear dynamics in methyl iodine (CH3I) molecule with an X-ray pump X-ray probe scheme. The pump-probe experiment was realized with a two-mirror X-ray split and delay apparatus. Time-of-flight mass spectra at various pump-probe delay times were recorded to obtain the time profile for the creation of high charge states via sequential ionization and for molecular dissociation. We observed high charge states of atomic iodine up to 29+, and visualized the evolution of creating these high atomic ion charge states, including their population suppression and enhancement as the arrival time of the second X-ray pulse was varied. We also show the evolution of the kinetics of the high charge states upon the timing of their creation during the ionization-dissociation coupled dynamics. We demonstrate the implementation of X-ray pump-probe methodology for investigating X-ray induced molecular dynamics with femtosecond temporal resolution. The results indicate the footprints of ionization that lead to high charge states, probing the long-range potential curves of the high charge states