0000000001164140
AUTHOR
R. Mondelli
The structure and stereochemistry of atractyligenin
Abstract The structure of atractyligenin C19H28O4, the nor-diterpenoidic aglycone of atractyloside C30H44O16S2K2 has been substantiated as Ia. The absolute configuration shown in Ia proves it to be a derivative of (−)kaurene.
Effect of simulated brushing on surface roughness and wear of bis-acryl-based materials submitted to different polishing protocols
Provisional materials must have enough strength to withstand masticatory loads without suffering deformation or fracture, and their surfaces must have good finishing and polishing characteristics to reduce biofilm accumulation. Thus, the purpose of this study was to investigate the best polishing protocol for different bis-acryl composite resins in comparison with a conventional resin composite and a self-curing acrylic resin aiming to obtain a smooth restoration surface and resistance to wear.One hundred and four samples (15 mm length x 5 mm width x 4 mm depth) were prepared and divided into four groups according to the material tested: Protemp 4 and Structur 3 bis-acryl composite resins, …