Physicochemical and Antibacterial Characterisation of a Novel Fluorapatite Coating

Peri-implantitis remains the major impediment to the long-term use of dental implants. With increasing concern over growing antibiotic resistance there is considerable interest in the preparation of antimicrobial dental implant coatings that also induce osseointegration. One such potential coating material is fluorapatite (FA). The aim of this study was to relate the antibacterial effectiveness of FA coatings against pathogens implicated in peri-implantitis to the physicochemical properties of the coating. Ordered and disordered FA coatings were produced on the under and upper surface of stainless steel (SS) discs respectively, using a hydrothermal method. Surface charge, surface roughness, wettability and fluoride release were measured for each coating. Surface chemistry was assessed by X-ray photoelectron spectroscopy and FA crystallinity by X-ray diffraction. Antibacterial activity against periodontopathogens was assessed in vitro using viable counts, confocal and scanning electron (SEM) microscopies. SEM showed that the hydrothermal method produced FA coatings predominately aligned perpendicular to the SS substrate or disordered FA coatings consisting of randomly aligned rod-like crystals. Both FA coatings significantly reduced the growth of all the examined bacterial strains in comparison to the control. The FA coatings, and especially the disordered ones, presented significantly lower charge, higher roughness and area when compared to the control, enhancing bacteria–material interactions and therefore bacterial deactivation by fluoride ions. The ordered FA layer reduced not only bacterial viability but adhesion too. Ordered FA crystals produced as a potential novel implant coating showed significant antibacterial activity against bacteria implicated in peri-implantitis which could be explained by a detailed understanding of their physicochemical properties

Epidemiology of pneumoconiosis in coalminers of Nord-Pas-de-Calais in France

This is a longitudinal study of 3 167 active or retired pneumoconiotic coalminers from Nord - Pas de Calais collieries (HBNPC) recognised through medico-legal decision over three defined periods: 1942-61, 1952-81 and 1982-87

Trueness of CAD/CAM digitization with a desktop scanner – an in vitro study

Desktop scanners are devices for digitization of conventional impressions or gypsum casts by indirect Computer-Aided Design/Computer-Assisted Manufacturing (CAD/CAM) in dentistry. The purpose of this in vitro study was: 1, to investigate whether virtual models produced by the extraoral scanner have the same trueness as sectioned casts; and 2, to assess if digitization with an extraoral scanner influences the surface information

BONE-MINERAL STATUS IN GROWTH HORMONE-DEFICIENT MALES WITH ISOLATED AND MULTIPLE PITUITARY DEFICIENCIES OF CHILDHOOD ONSET.

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