Antibacterial 3D-printed PMMA/ceramic composites

Following the rising interested on 3D-printed technologies, this research explores the possibility to use stereo-lithography to 3D print PMMA resins reinforced with up to 15% in weight of antibacterial ceramic powders. Three different reinforcements were tested, following previous literature data: aluminum nitride, titanium oxide and barium titanate. Between the three powders, the most uniform dispersion was achieved using aluminum nitride. Initial screenings with mixed and cured composite resins showed that between the three composite materials, only aluminum nitride or barium titanate PMMA showed a clear antibacterial effect when compared to the pristine reference, with aluminum nitride being the most effective against E. coli. When 3D printed using stereo-lithography, the composite containing aluminum nitride showed an even higher degree of dispersion and comparable antibacterial effects. Moreover, aluminum nitride reinforced PMMA resins showed good mechanical properties, comparable to the basic resin, and could be further strengthened by a standard post-curing process.

The influence of base resin of removable dentures on the planktonic growth of individual representatives of oral microflora

Introduction. Microbiological researches of the role of denture base materials in violation of the oral cavity micro ecology were conducted. Aim. Therefore, the purpose of research is to study the effect of different polymeric materials on denture bases, on the intensity of planktonic growth of resident and transient representatives of oral cavity microflora in a periodic culture on the basis of registration of its optical density. Material and methods. 7 types of denture base materials and their influence on the planktonic growth of microorganisms have been studied. Results. The planktonic growth of the S. oralis strain was suppressed by all base materials: SYNMA (by 35.5%), Bre.Flex (by 27.5%) and Protacryl-M (by 25.7%), in the smallest – Nylon (by 5.4%), Villacryl (by 9.5%). Conclusions. Through experimental research, we have proved the direct involvement of basic resin materials in changes in the oral cavity micro ecology and the process of occurrence of prosthetic stomatitis.

The analysis of ion exchange resin adsorb Li from ash solution

Purpose This paper aims to take the four resin as adsorbent and coal ash alkaline solution as the material and use the single factor experimental method to study absorption influence factors for each resin to absorb lithium. At the same time, the authors got the special properties of some kinds of resin and compared the test results of each resin at the optimum factors. Design/methodology/approach Because many factors affect the test, this study uses the method of comparison and control variables. This method study on the influencing factors of ion exchange resin adsorption Li+. Findings In these adsorption experiments, the basic resin adsorption effect is more obvious. The optimum adsorption conditions are as follows: resin quality is 0.1 g, the volume of fly ash solution is 100 ml, magnetic stirrer speed is 140 r/min and the adsorption time is 60 min. Under these conditions, the adsorption rate of Li+ could reach 25.17 per cent aluminum. Originality/value Li extracted from coal ash can not only relieve the lithium resources in short supply but can also provide a new mode to the field of coal resources in recycling economy and transition economy. At the same time, the extraction of Li resources will provide an important reserve of raw materials for the future of nuclear power plant.