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This study looks for grounds to alter the chemical composition (phosphate, calcium, silica and carbonate), dissolution properties, structure and nanotopography of the biomimetically processed surfaces on bioactive ceramics to optimize their shown ability to influence bone cell behaviour and production of new bone. In the bone environment desirable characteristic of these materials is their ability to be remodeled by natural osteoclastic resorption. Different silica and carbonate containing calcium phosphate layers were prepared on bioactive glasses 9 (S53P4) and 1-98 (S53P2) and sol-gel processed pure silica SiO2 in C- and R-SBF (conventional and revised simulated body fluid) for varying periods of time. It was shown that in R-SBF the CaP layer formed faster compared to C-SBF. The CaP layer in the R-SBF contained more carbonate (CO3(2-)) compared to that formed with the same immersion time in C-SBF. The CaP so formed in R-SBF with faster precipitation is more amorphous than the bonelike HCA formed in C-SBF. The results indicate that the most suitable surface for both osteoblasts and osteoclasts was found to be an amorphous CaP having mesoporous nanotopography and proper dissolution rate of calcium and silica.

Abstract: The effects of UV-radiation on the cleanability of three glazed tiles coated with ceramic sol–gel derived TiO2 were evaluated. A quantitative radiochemical determination method was used to measure oil and organic particle soil residues on the surface. Surfaces were characterized with topography and contact angle measurements. The observed effects of UV-radiation were greatest on rough surfaces, implying that increasing roughness increases the surface area available for photo-induced phenomena in the TiO2-surface. Organic particle soil was removed more efficiently after UV-radiation than without UV treatment, whereas UV-radiation did not affect the removal of oil soil. Contact angles decreased significantly after UV-radiation. [Copyright &y& Elsevier]

Abstract: The aim of this study was to establish the effects of different coatings on the cleanability of glazed ceramics. The surface properties were examined with a contact angle meter, a contact profilometer and a confocal microscope. The surfaces were soiled with three radiochemical model soils: inorganic particle soil, organic particle soil and oil soil. Soil adhesion on surfaces was measured with a quantitative radiochemical procedure. Generally, cleanability of the particles present in the model soil was found to be affected by the roughness of the surfaces; however, the cleanability of the oil in the model soils correlated with the contact angle of water on the surfaces. Coating of glazes, especially with fluoropolymer film, generally increased the contact angle values. The coatings affected the cleanability of ceramics somewhat: particle soils were removed most efficiently from glazes coated with TiO2 and Zr. By contrast the oil soil residues of the fluoropolymer surfaces were the lowest. The cleanability results of the three model soils based on inorganic or organic particles or oil were different indicating differences between the cleanabilities of these main components of the soils. [Copyright &y& Elsevier]