Amino-acids, peptides, and protein hydrolysates, together with their coordinating compounds, have various applications as fertilizers, nutritional supplements, additives, fillers, or active principles to produce hydrogels with therapeutic properties. Hydrogel-based patches can be adapted for drug, protein, or peptide delivery, and tissue healing and regeneration. These materials have the advantage of copying the contour of the wound surface, ensuring oxygenation, hydration, and at the same time protecting the surface from bacterial invasion. The aim of this paper is to describe the production of a new type of hydrogel based on whey protein isolates (WPI), whey protein hydrolysates (WPH), and gelatin. The hydrogels were obtained by utilizing a microwave-assisted method using gelatin, glycerol, WPI or WPH, copper sulfate, and water. WPH was obtained by enzymatic hydrolysis of whey protein isolates in the presence of bromelain. The hydrogel films obtained have been characterized by FT-IR and UV-VIS spectroscopy. The swelling degree and swelling kinetics have also been determined.

A beautiful smile is an important feature when it comes to a pleasant appearance of the face, and one of the most common situations that drive patients to book a dental appointment is tooth discoloration. Tooth bleaching is the treatment of choice for extrinsic tooth discoloration, as it is a cheap, fast, and minimally invasive procedure. This study aimed to provide comparative information on the perceptions of both patients and dentists regarding different whitening methods and on the factors involved in people’s willingness to recommend and use a bleaching procedure. In addition to this, this study evaluated the degree of satisfaction in relation to the bleaching methods and materials used; it also evaluated the following: negative side effects, economic characteristics and the patients’ perceptions of the aesthetic appearance of their dental arches, especially tooth color. The subjects that participated in the present study were selected based on their background and were then divided into two categories. The first group consisted of 120 patients who had received tooth-bleaching treatments in dental clinics during the study and the second group consisted of 127 dentists. A conventional sampling method was used. The study aimed to define a relationship between multiple aspects of the tooth-bleaching procedure, including the patients’ desires and their general knowledge of this procedure. Tooth color and the way it changes is a very important factor that motivates patients to come to the dentist for whitening procedures. Patients showed the highest levels of satisfaction with the results of in-office bleaching procedures. In the group consisting of dentists, satisfaction levels were higher for the procedure of home bleaching supervised by a dentist. Factors influencing the choice of bleaching materials are appreciated differently by dentists and patients. Furthermore, the rate of patients using OTC (over the counter) products was found to be high. Further research is needed to find more effective and safer alternatives to home tooth-bleaching procedures.

The novelty of this study consists of the formulation and characterization of three experimental bleaching gels with hydroxylapatite oxides and fluorine (G28®, G29®, G30®) based on natural fruit extracts compared to the commercial Opalescence 15% (GC, Ultradent, South Jordan, UT, USA). Studies have been conducted on the effect that the experimental bleaching gels have on the color and morphology of different restorative materials (Nanofill®-Schulzer, P.L. Superior Dental Materials GmbH, Hamburg, Germany, and experimental nanocomposites (P11®, P31®, P61®)), immersed in coffee and artificial saliva (for 10 days and 30 days). The study also includes a cytotoxicity test on the gels and nanocomposites after bleaching, with ISO 109993-5 protocols on human dental follicle stem cells. UV-VIS spectroscopy, computerized measurement, and fluorescence spectrometry were used in order to observe the color changes, while the microstructure of the surface was investigated by Scanning Electron Microscopy (SEM). All of the samples immersed in coffee showed the highest color shift in comparison to the baseline. The color difference ΔE values obtained using the two methods (UV-Vis, computerized based on digital images) both after coloring and bleaching, respectively, were different for all four types of nanocomposites stored in the coffee, while no difference was observed in those stored in artificial saliva. The studied experimental gels and nanocomposites had a low cytotoxic effect on cell cultures after bleaching.

By-products from the meat and dairy industries are important sources of high biological value proteins. This paper explores possibilities for improving the swelling and integrity of a cross-linked whey and gelatin hydrogel with different amounts of CuSO₄ × 5H₂O. Overall, swelling tests demonstrate that cross-linked samples show a better hydration capacity and stability in the hydration medium, but different copper concentrations lead to different swelling behavior. At concentrations smaller than 0.39%, the sample lasts for 75 h in a water environment before beginning to disintegrate. At a concentration of copper sulphate higher than 0.55%, the stability of the sample increased substantially. The swelling kinetics has been investigated. The diffusion constant values increased with the increase in copper concentration, but, at the highest concentration of copper (0.86%), its value has decreased. Spectroscopy analyses such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-VIS), and nuclear magnetic resonance (NMR) relaxometry analyses revealed changes in the secondary and tertiary structure of proteins as a result of the interaction of Cu²⁺ ions with functional groups of protein chains. In addition to its cross-linking ability, CuSO₄ × 5H₂O has also shown excellent antibacterial properties over common bacterial strains responsible for food spoilage. The result of this research demonstrates the potential of this hydrogel system as a unique material for food packaging.

Among esthetic procedures, teeth whitening is a common and often used treatment for patients who seek good teeth appearance. We developed an experimental green tea extract and an experimental green tea gel for enamel restoring treatment after bleaching. We also tested the antibacterial and antifungal effect of the experimental extract against specific endodontic and cariogenic microorganisms. The green tea extract antibacterial action was determined by the disk-diffusion method using Peptostreptococcus anaerobius (ATCC27337), Corynebacterium xerosis (ATCC 373), Streptococcus mutans (ATCC 25175) and Candida albicans (ATCC 10231) strains. Enamel microstructure was investigated by SEM analysis, and surface details were revealed by AFM. The inhibition zones around the wells showed evident antimicrobial activity of the experimental extract. In the presence of Candida albicans (ATCC 10231), the extract showed no antifungal activity. The enamel’s surface roughness and hydroxyapatite prism aspects were the parameters followed throughout the study. The experimental green tea extract is efficient against some microorganisms commonly found in the oral cavity. However, the studied extract had no antifungal effect. The results show that after bleaching with the experimental gel, we obtained the best surface parameters, similar to healthy enamel.

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.