Prevention of acidic attack on tooth enamel surfaces using polishing paste containing ion-releasing filler.

The purpose of this study was to investigate the ability of polishing paste containing surface pre-reacted glass-ionomer (S-PRG) filler to prevent acidic attack on tooth enamel surfaces. Resin composites were filled in the standardized cavities and finished with silicon carbide paper. These specimens were divided into three groups: the unpolished "control" group, the "PRG" group polished with S-PRG paste, and the "DDP" group polished with diamond-containing polishing paste. Following polishing, the specimens were immersed in a lactic acid buffer solution for 28 days. Optical coherence tomography (OCT) signals were measured to obtain the signal intensity and width at 1/e2 at selected locations on the enamel surface adjacent to the restoration. Although signal intensity significantly increased in all groups, widths at 1/e2 did not change significantly in the PRG group. For both the control and DDP groups, signal intensity and width at 1/e2 increased and decreased over time, respectively.

Cooperative Self-Assembly of Carbazole Derivatives Driven by Multiple Dipole-Dipole Interactions.

Carbazole possessing phenylisoxazoles self-assembled in a cooperative manner in decalin. X-ray crystal structure analysis revealed that the isoxazole dipoles align in a head-to-tail fashion. DFT calculations suggested that the linear array of dipoles induced the polarization of each dipole, leading to an increase in dipole-dipole interactions. This dipole polarization resulted in cooperative assembly.