The growing interest in the appearance and color of teeth has led to the emergence of a wide range of teeth whitening methods, both in dental offices and in patients’ homes. Concerns about the possible side effects or toxic effects of peroxide-based whitening gels leads to the identification of alternative whitening methods, based on natural compounds with mild action on tooth enamel and remineralizing effect. In this context, this study describes the preparation and in vitro analysis of whitening gels based on natural active agents—bromelain, quince and whey—using organic (polyacrylate, polyethylene glycol) and/or inorganic (silicate) excipients. Five natural products gels were prepared, containing bromelain extract, quince extract and whey, in various proportions. Two supplementary gels, one containing Lubrizol and another containing SiO₂, were prepared. All gels were submitted for multiple in vitro analysis such as: SDS-PAGE analysis, UV-vis and FTIR spectroscopy, SEM microscopy, antibacterial activity on Streptococcus mutans ATCC 25175, Porphyromonas gingivalis ATCC 33277, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. The quince extract sample was the only one which completely discolored the blue dye on SDS-PAGE analysis. On the UV-vis spectra, the 303 nm band is assigned to an in situ modified form of bromelain. SEM images of gels containing SiO₂ particles show evident marks of these particles, while the rest of the gels containing Lubrizol or whey are more uniform. Regarding antibacterial tests, the SiO₂ gel samples did not show inhibition in any strains, but the other tested samples varied in the size of the inhibition diameter depending on the amicrobial strain tested; the protease activity of bromelain modulates the composition of the added whey proteins. Bromelain added as a nanoencapsulated assembly better preserves its integrity. The prepared gels showed antibacterial properties.

The objective of our study was to test the bleaching effect of two whitening gels, on stained hybrid ceramic material used for Computer Aided Design/ Computer Aided Manufacturing technology. 40 rectangular specimens 12/14/1mm were prepared from Vita Enamic blocks. All specimens were accelerated stained, and distributed in two groups. Group 1 was bleached using Opalescence PF 15% (Ultradent, USA), group 2 was bleached using an experimental gel containing natural products. ΔE* (used to assess the color changes) was above the perceptibility threshold of 1.2 in 40%; and the WID (used to assess the bleaching process in dentistry) showed high units for both bleaching gels. Hybrid ceramics staining showed moderate results, while the bleaching effect was present, with no statistical difference between the discolorations produced by the two bleaching gels (p<0.05). SEM images showed that the bleaching gels did not affect the surface structure of the material.

Petroleum hydrocarbon pollution is a serious environmental and human health problem. In recent decades, the impact of this substance has been profound and persistent, affecting the balance of aquatic and terrestrial ecosystems and leading to significant physical and psychosocial effects among the population. Natural sources (crude oil, natural gas, forest fires, and volcanic eruptions) and anthropogenic (road traffic, smoking, pesticide use, oil drilling, underground water leaks, improper oil spills, industrial and mining waste water washing, etc.), the molar weight of the hydrocarbon, and the physicochemical properties are important factors in determining the degree of pollution. The effects of pollution on the environment consist of altering the fundamental structures for sustaining life (infertile lands, climate change, and loss of biodiversity). In terms of human health, diseases of the following systems occur: respiratory (asthma, bronchitis), cardiovascular (stroke, heart attack), pulmonary (infections, cancer), and premature death. To reduce contamination, sustainable intervention must be carried out in the early stages of the pollution-control process. These include physical techniques (isolation, soil vapor extraction, solvent extraction, soil washing), chemical techniques (dispersants–surfactants, chemical oxidation, solidification/stabilization, thermal desorption), biological techniques (bioremediation, phytoremediation), and indigenous absorbents (peat, straw, wood sawdust, natural zeolites, clays, hemp fibers, granular slag, Adabline II OS). Due to the significant environmental consequences, decisions regarding the treatment of contaminated sites should be made by environmental experts, who must consider factors such as treatment costs, environmental protection regulations, resource recovery, and social implications. Public awareness is also crucial, as citizens need to understand the severity of the issue. They must address the sources of pollution to develop sustainable solutions for ecosystem decontamination. By protecting the environment, we are also safeguarding human nature.

This comprehensive review highlights the growing significance of graphitic carbon nitride (g-C₃N₄) as a multifunctional material with applications spanning diverse scientific and technological domains. Based on an extensive literature from electronic databases such as Web of Science, PubMed and Google Scholar, we provide an in-depth discussion of the fundamental structural configurations of g-C₃N₄, namely the triazine- and heptazine-based frameworks, which form the basis of its unique physicochemical and electronic properties. The two predominant synthesis strategies—thermal polymerization and solvothermal/hydrothermal routes—are examined in detail and illustrated through representative schematic models to elucidate their underlying mechanisms and resulting structural variations. Advanced surface characterization techniques, such as atomic force microscopy (AFM) and scanning tunneling microscopy (STM), are also discussed in the context of their application to materials, including Highly Oriented Pyrolytic Graphite (HOPG), graphene oxide, and carbon nitride. These analyses provide insights into nanoscale surface topography and structural attributes, with HOPG serving as a well-established reference material for comparison. The review also addresses the biological activities and potential applications of g-C₃N₄, particularly in the context of its photocatalytic, antimicrobial, and biocompatible properties. Despite substantial progress in other research fields, a notable gap remains in the exploration of g-C₃N₄ for oral and dental applications. This limitation is largely attributed to the scarcity of systematic studies and limited published data in this emerging area. Accordingly, this review identifies promising opportunities for future research aimed at harnessing the distinctive properties of g-C₃N₄ for innovative developments in oral healthcare and dental material science.

The paper presents some aspects referring to the synthesis of niobium activated yttrium orthotantalate phosphor (YTaO₄:Nb), utilizable in the manufacture of X-ray intensifying screens for medical diagnosis. The influence of some preparative conditions such as activator concentration and firing regime on the crystalline structure and luminescent characteristics are investigated. Photoluminescence spectroscopy, X-ray diffraction and FT-IR spectroscopy are used to evaluate the material quality.

Direct bonding of the bracket to the enamel is the elective procedure for the orthodontic treatment. Among various factors influencing the adhesive force at the enamel level, the etching technique seems to be the most important one. The present study aims at evaluating the influence of the storage media and the etching technique used, on the bond strength between different bracket types and dental structures. The results of this study showed that, regardless of the brackets and the immesion solution used, by working with the classic etch and rinse technique, the adhesion force is higher than by using a self-etching adhesive.