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OBJECTIVES: The objective of this study was to observe and to measure the impact of corundum sandblasting on the thickness of the Immediate dentin sealing layer. METHODS: 20 recently extracted molars were collected and divided randomly into two groups. A standardized preparation was performed on each tooth and the Optibond FL dentin bonding agent (Kerr, Orange, USA) was applied on the prepared surface according to the manufacturer 's instructions. The surface was then partially sandblasted. RONDOflex plus 360 (KaVo, Bieberach an der Riss, Germany) and Airsonic Mini-Sandblaster (Hager&Werken, Duisburg, Germany) were used. Microscope observations were made. RESULTS: The arithmetic mean of the Optibond FL dentin bonding agent film thickness was 48.72 μm (Group 1=45.55 μm and Group 2=51.88 μm). The dentin bonding agent layer thickness was reduced to the average value of 17,12 μm by RONDOflex plus 360 sandblasting (Group 1). The zero value was recorded in 16 % of the locations. The Airsonic Mini-Sandblaster sandblasting changed the average thickness of the dentin bonding agent layer to 13.25 μm with 31 % of zero values (Group 2). CONCLUSION: The results of this research lead to a reflection on modifications of the immediate dentin sealing procedure (Tab. 4, Fig. 3, Ref. 28). [ABSTRACT FROM AUTHOR]

Desorption nanoelectrospray (nanoDESI) was described in 2007 and it represents a miniaturized version of desorption electrospray without the assistance of the nebulizing gas. Compared to DESI, a nanoelectrospray tip (2 ± 1 μm I.D.) generates primary charged droplets of smaller sizes and lower spray liquid flow rates. This is the first report on utilization of nanoDESI for mass spectrometry imaging (MSI). Its new coupling with a Q-TOF instrument allowed faster mass spectra acquisition (4 Hz) essential for MSI of fine surface details. To evaluate nanoDESI potential for mass spectrometry imaging, etched glass substrates with Rhodamine B patterns of different dimensions were prepared. The Rhodamine B lines were analysed in 1D scanning mode and their width was determined experimentally by nanoDESI measurement. The experimental data revealed that the lateral resolution of nanoDESI is close to 30 μm along the x-axis (orthogonal to the inlet). 2D scanning mode confirmed good resolution along both axes as dye squares with dimensions about 60 μm × 60 μm were easily distinguished. The low flow rate of the spray liquid reduced undesirable analyte washing effects, which allowed repeated scanning analysis of the surface. The presented results demonstrate the applicability of nanoDESI for high surface resolution mass spectrometry imaging. [ABSTRACT FROM AUTHOR]