Recommendations on the clinical application of air polishing for the management of peri-implant mucositis and peri-implantitis.

Air polishing was introduced as an alternative approach for the supra- and submucosal biofilm management at dental implants. An international expert meeting involving competent clinicians and researchers took place during the EUROPERIO 8 conference in London, UK, on 4 June 2015. Prior to this meeting a comprehensive systematic review dealing with the efficacy of air polishing in the treatment of peri-implant mucositis and peri-implantitis was prepared and served as a basis for the group discussions. This paper summarizes the consensus statements and practical recommendations on the clinical application of air polishing for the management of peri-implant mucositis and peri-implantitis.

Geometry and solvent-polarity dependences of the relaxation dynamics of the singlet excited state of center-to-edge phosphorus(V) porphyrin heterodimers.

Para- and meta-isomers of center-to-edge phosphorus(V) porphyrin heterodimers (p- and m-Pm-PCl2) composed of a phosphorus(V) tetraphenylporphyrin (P) and a phosphorus(V) tetrakis(4-methoxyphenyl)porphyrin (Pm) were synthesized to investigate the geometry and solvent-polarity dependences of the relaxation dynamics of the lowest singlet excited state (S1) of the porphyrin dimer. The geometrical difference between m- and p-Pm-PCl2 in solution was confirmed by 1H NMR on the basis of the porphyrin ring current model. By the photoexcitation of the dimers, only the fluorescence from 1Pm*-P was observed in both dimers because of the efficient singlet energy transfer from the higher energy 1P* to the lower energy 1Pm*. However, the 1Pm*-P fluorescence had features that differ from the typical fluorescence from monomeric 1Pm*, especially for the solvent-polarity dependence of the quantum yields. Furthermore, all the fluorescence decay curves of 1Pm*-P were double-exponential. The special fluorescence features of 1Pm*-P are due to the equilibrium between 1Pm*-P and the charge-transfer (CT) excited state of the dimer ((Pm-P)CT). By the excited-state equilibrium, 1Pm*-P is efficiently quenched through (Pm-P)CT in highly polar solvents. The contribution of (Pm-P)CT to the decay process of 1Pm*-P is more remarkable in m-Pm-PCl2 than in p-Pm-PCl2, depending on the interaction between the two porphyrin -systems in the heterodimer.