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The evaluation of the effect of carbon dioxide laser radiation on dentine tissue

Ryniewicz J., Ryniewicz W. I., Loster J. E., Wieczorek A., Pytko-Polończyk J.

Acta of Bioengineering and Biomechanics

2017

Vol. 19, no. 1

181--188

Purpose: Tissue constitution and construction determine the scope of the structural changes that develop under laser light. The aim of this study was to analyze the effects of carbon dioxide (CO2) laser light on the structure and elemental composition of dentine. Methods: The evaluation was conducted on samples from extracted teeth. The surface of the dentine was exposed to the radiation from a CTL 1401 CO2 laser (Centre of Laser Technology, Poland). The radiation and frequency parameters were as follows: group I with 5 W and 1 Hz, group II with 10 W and 1 Hz, group III with 5 W and 5 Hz, and group IV with 10 W and 5 Hz. The altered dentine structure was macroscopically and microscopically evaluated using a Nova NanoSEM 200 Scanning Electron Microscope (FEI Europe) with integrated microanalysis X-ray system for elemental analysis in points. Results: There were significant differences between groups in the macro- and microstructure of laser defects. Conclusions: CO2 laser radiation causes irreversible, destructive changes in dentine. The structural dentine lesions developed under the influence of the CO2 laser radiation may hinder proper adhesion of bonding systems with the damaged tissue. Laser defects in the structure should be treated like defects of noncarious origin requiring preparation and filling with composite materials in accordance with the procedures.

Application of neutron activation for investigation of Fe3O4 nanoparticles accumulation by plants

Bystrzejewska-Piotrowska G., Asztemborska M, Stęborowski R., Polkowska-Motrenko H., Danko B., Ryniewicz J.

Nukleonika

2012

Vol. 57, No. 3

427-430

As a result of the rapid development of nanotechnology and increasing application of nanoproducts in many areas of everyday life, there is a growing risk of production of nanowastes potentially dangerous for the environment. This makes it necessary to investigate the accumulation and toxicity of nanoparticles (NPs) at different trophic levels. In the studies neutron activation was applied for the investigation of iron (II,III) oxide nanoparticle (Fe3O4-NPs) accumulation by Lepidium sativum and Pisum sativum L. Plants were cultivated on growth medium contaminated with different concentrations (0.01-10 mmolźL-1) of Fe3O4-NPs. For the identification of the presence of Fe3O4-NPs in plant tissues gamma spectrometry following iron oxide (II,III) nanoparticles irradiation was applied. Both plant species were found to accumulate iron (II,III) oxide nanoparticles. The highest content of NPs was found in plant roots, reaching 40 g/kg for Pisum sativum L. More than 90% of accumulated NPs were found in roots. Accumulation of Fe3O4-NPs was found to depend on the concentration of nanostructures in the growth medium. The transfer factor for Lepidium sativum roots and shoots and Pisum sativum L. shoots decreased with increasing NP concentration in the medium; for Pisum sativum L. roots the tendency was reversed. Neutron activation of nanoparticles was shown to be a powerful tool for tracing the environmental fate of NPs and their uptake and accumulation in organisms.