Entwicklung und Anwendungen von Biokeramik

The antimicrobial effect of staphylococcus aureus, Streptococcus mutans, E. coli and Candida albicans are dependent on surface properties and restorative dental materials types. The aim of this study was to evaluate the effect of antibiotics on the residual natural saliva (after Filtek, glass-ionomer, porcelain and zirconia takeout from it). Also, the effect of brushing on fungi and bacteria growth in these surface materials was characterized. The results show that, bacterial growth around Filtek, glass ionomer, porcelain, and zirconia materials after takeout from saliva that is meant these materials have no resistance for E. coli, staphylococcus aureus, Streptococcus mutans and Candida albicans. The color of residual saliva changed. All antibiotics caused inhabitation zone except Ampicillin. Ciprofloxacin shows significant inhibition zone for all used materials. Also, brushing removed most if not all fungi and bacteria formed on surface dental materials.

Nanotechnology implies to the manipulation, reduction and fabrication of materials at nano scale. Nanoparticles, exhibiting distinct morphological characteristics which is quite different from their bulk form. In recent years nanoparticles have been produced by industries for commercial application having many benefits. Biosynthesis of nanoparticles attracts many researchers and industries to explore microorganisms such as Bacteria, Fungi, Algae etc as the perfect biological system for the assembly of different nanoparticles. Fungi being the most suitable as mycosynthesis is not only ecofriendly but also makes the downstream processing for product recovery much easier.

Some phosphate glasses containing different amounts of by-pass cement dust (BCD) were prepared by the melt quenching method. The selected molecular composition was [(100-x)% - P2O5 (x)% BCD (where 30≤ x≥60)]. The obtained experimental density and molar volume values were inspected and were then compared with those obtained empirically for the close packed structure of the corresponding compounds. The comparison between experimental and emperical values evidenced the short range order of the studied samples. The electric and dielectric properties were thoroughly investigated. The appearance of maxima and minima in the total conductivity BCD concentration dependence can be attributed to the mixed alkali – alkaline earth effect (MAAE) and to the presence of considerable amount of CaO. The suitability of such glasses to act as gamma-ray shielding materials was thoroughly investigated, and correlation between the chemical composition (the BCD concentration) and gamma-ray attenuation behavior was established.