Evaluation of the Fluoride Releasing and Recharging Abilities of Various Fissure Sealants.

Purpose: To evaluate the fluoride release from different fissure sealants sold mainly in non-Western countries via a curve-fitting method, and to investigate the ability of these materials to be recharged with fluoride.

Materials And Methods: Four different fissure sealants which the manufacturers claim to release F- were tested; glass-ionomer cement Argecem (AC), the composite resins Fisskhim (FK), Fissulight (FL), Helioseal F (HF). Helioseal (HS), a composite resin not declared to release F, was used as a negative control.

Self-localization of polariton condensates in periodic potentials.

We predict the existence of novel spatially localized states of exciton-polariton Bose-Einstein condensates in semiconductor microcavities with fabricated periodic in-plane potentials. Our theory shows that, under the conditions of continuous nonresonant pumping, localization is observed for a wide range of optical pump parameters due to effective potentials self-induced by the polariton flows in the spatially periodic system. We reveal that the self-localization of exciton-polaritons in the lattice may occur both in the gaps and bands of the single-particle linear spectrum, and is dominated by the effects of gain and dissipation rather than the structured potential, in sharp contrast to the conservative condensates of ultracold alkali atoms.

Controlled transport of matter waves in two-dimensional optical lattices.

We propose a method for achieving dynamically controllable transport of highly mobile matter-wave solitons in a driven two-dimensional optical lattice. Our numerical analysis based on the mean-field model and the theory based on the time-averaging approach demonstrate that a fast time-periodic rocking of the two-dimensional optical lattice enables efficient stabilization and manipulation of spatially localized matter wave packets via induced reconfigurable mobility channels.