Abstract This study aims to develop a nano-sized fluoridated layered double hydroxide (LDH)-based release system via hydrothermal treatment for the controlled delivery of fluoride (F-) ions in the oral environment. The synthesis of conventional LDH-type (C-LDH) precursor nanomaterials was conducted using a co-precipitation method at constant pH, and the nanoparticulate-LDH (N-LDH) was synthesized by a hydrothermal procedure. Fluoride LDH (F-LDH) products were obtained through indirect synthesis using the precursor ion-exchange technique by varying the agitation time (2 and 24 h) and temperature (25 and 40 °C) to produce 12 material samples. The materials were characterized by energy dispersive x-ray, hexamethyldisilazane, digital radiography x-ray, Fourier-transform infrared, thermogravimetric analysis, and scanning electron microscopy. Additionally, the F-release kinetic profile was evaluated for 21 d in neutral and acid media with mathematical model analysis. Products with varying F-quantities were obtained, revealing specific release profiles. In general, there was a higher F-release in the acid medium, with emphasis on F-LDH-8. Fluoride-LDH and controlled fluoride delivery was successfully obtained, proving the potential of these nanomaterials as alternative anti-caries agents.

The present prospective work of scientific articles related to foods and natural products with anti-Covid activity in databases in order to present a scientific community, to governments and society as main foods, nutraceuticals and medicinal plants as strategies used by countries during the COVID-19 pandemic. A review of articles on food, medicinal plants and biotechnology was carried out in databases of scientific articles such as: CAPES journals, PubMed, Elsevier's Science Direct, Willey on library library, Taylor & Francis Springer-Nature database, BMC, Hindawi, Scielo, ACS - American Chemical Society, Google Scholar, in addition to the Patent Database “The LENS” and “Questel-Orbit”. Foods used in daily life such as garlic, ginger, turmeric, sour orange, vegetables, lactobacilli demonstrate proven anti-virus action. Medicinal plants used by Traditional Chinese, Korean and Indian Medicine also demonstrate anti-Covid activity and used during the coronavirus outbreak. Some medicinal plants, green propolis extract, red propolis extract, royal gelly, polen, honey have also been cited as anti-covid, natural anti-inflammatory and immunomodulatory products.

O presente trabalho prospectou artigos científicos relacionadas à alimentos e produtos naturais com atividade anti-Covid com o intuito de apresentar, à comunidade científica, aos governos e à sociedade, dados sobre as principais estratégias nutracêuticas, biotecnológicas e plantas medicinais utilizadas em alguns países durante o enfrentamento da pandemia COVID-19. A revisão de artigos sobre alimentos, plantas medicinais e produtos biotecnológicos foi realizada nas bases de dados periódicos da CAPES, PubMed, Science Direct, Willey on line library, Springer-Nature, Taylor & Francis, BMC, Hindawi, Scielo, ACS – American Chemical Society, Google acadêmico, “The LENS” e Questel-Orbit. Alimentos de uso frequente como alho, gengibre, cúrcuma, laranja azeda, vegetais e lactobacilos demonstraram ação anti-coronavirus comprovada. Foram descritos usos de plantas medicinais da Medicina tradicional Chinesa, Coreana, Indiana bastante utilizadas durante a pandemia. Algumas plantas medicinais e nutracêuticos como: extrato de própolis verde e extrato de própolis vermelha brasileiras, geleia real, pólen e mel também foram citados como produtos anti-covid, antiinflamatórios naturais e imunomodulatórios.

INTRODUÇÃO: A absorção/adsorção de moléculas de água por monômeros hidrofílicos dentro de materiais resinosos expostos à umidade da boca pode resultar em degradação. OBJETIVO: Este estudo avaliou sorção e solubilidade de resinas compostas à base de metacrilato e silorano em contato com saliva artificial, nos períodos de um dia (curto prazo), e 30 e 90 dias (médio prazo). MATERIAL E MÉTODO: Sessenta corpos de prova foram confeccionados com as resinas Filtek® Z250 e Filtek® P90 Silorano (3M/ESPE), e depois imersos em saliva artificial a 37 ± 1 ºC durante um, 30 e 90 dias. Os dados foram analisados usando-se ANOVA um fator/dois fatores seguido dos testes Tukey ou Tamhane (α = 0,05). RESULTADO: As médias de sorção das duas resinas aumentaram com o tempo (p = 0,001). A sorção de Z250 (1 e 90 d) foi significativamente maior do que de P90 (p = 0,008), com valores semelhantes após 30 dias. A solubilidade das resinas também aumentou com o tempo, com diferença significativa entre todos os períodos (p = 0,001), exceto para a resina P90 (entre 1 e 30 d). Não houve diferença estatística significante entre os grupos Z250 (1 d) e P90 (1 dia), Z250 (1 d) e P90 (30 d), e Z250 (30 d) e P90 (90 d). Para os demais pares, comprovaram-se diferenças significativas (p < 0,001). CONCLUSÃO: As propriedades de sorção e solubilidade das resinas compostas testadas foram influenciadas pelo tempo de exposição à saliva artificial. O silorano teve desempenho ora melhor ora semelhante à resina de metacrilato.

INTRODUCTION: The absorption/adsorption of water molecules by hydrophilic monomers within the resinous material exposed to the humid environment of the mouth may result in degradation. OBJECTIVE: This study evaluated the sorption and solubility of methacrylate-based resin and silorane in contact with artificial saliva after 1 day (short-term), 30 days and 90 days (medium-term). MATERIAL AND METHOD: Sixty samples were prepared with Filtek® Z250 and Filtek® P90 Silorano (3M/ESPE) and then immersed in artificial saliva at 37 ± 1 ºC for 1, 30 and 90 days. Data were analyzed using one-way/two-way ANOVA followed by the Tukey or Tamhane tests (α = 0.05). RESULT: The sorption and solubility of two resins increased with the evaluation time (p = 0.001). Sorption of Z250 (at 1 and 90 days) was significantly higher than that of P90 ( p = 0.008), and similar values were registered at 30 days. Resin solubility also increased with time and there were significant differences for all time periods (p = 0.001), except for P90 at 1 and 30 days. There were no significant differences between Z250 (1 day) and P90 (1 day), Z250 (1 day) and P90 (30 day), and Z250 (30 days) and P90 (90 days). Significant differences were shown for other pairings (p < 0.001). CONCLUSION: The solubility and sorption properties of the composites tested were influenced by time of exposure to artificial saliva. Silorane performed better than or similar results to methacrylate-based resin.

The aim of this study was to observe the influence of two light polymerization units (LED or halogen light) on the degree of conversion (DC) of three dental composites with lighter shades and a different photoinitiator system. The top (T) and bottom (B) surfaces of 60 discs of composite resin (Filtek™ Supreme, Filtek™ Z250, Tetric™ Ceram Bleach) cured either by LED or by halogen lamp (HL) were studied using an FT-Raman spectrometer. The degree of conversion (DC) was evaluated by following the changes in the intensity of the methacrylate C=C stretching mode at 1640 cm-1. The calculated DC ranged from 54.2% (B) to 73.4% (T) and from 60.2% (B) to 76.6% (T) for the LED and HL, respectively. LED and halogen devices were able to produce an adequate DC for all the resins tested.

O objetivo deste estudo foi avaliar o potencial de citotoxicidade do sistema adesivo Adper Single Bond 2 (SB), em função dos tempos pós-polimerização e imersão no meio de cultura para preparação dos extratos, observando-se os níveis de liberação de óxido nítrico (NO) e taxa de sobrevivência celular (MTT assay). Macrófagos alveolares de ratos Wistar foram expostos a 200 μL de extratos obtidos a partir da imersão de amostras do adesivo em meio de cultura (RPMI), imediatamente ou 24 h após sua polimerização, onde permaneceram durante 24 ou 72 h. RPMI puro e lipopolissacarídeos de E. coli foram utilizados como controles negativo e positivo, respectivamente. As células foram levadas à incubadora umidificada por 24 h. Os resultados foram submetidos ao teste "t" de Student (α=5%). As quantidades de NO produzido e células sobreviventes foram significativamente diferentes entre os grupos experimentais e grupos controle, mostrando que, independente do tempo pós-polimerização e tempo de elaboração dos extratos, o sistema adesivo causou uma intensa citotoxicidade sobre os macrófagos. Os efeitos citotóxicos não foram estatisticamente diferentes entre os grupos experimentais. Componentes químicos do SB liberados em meio aquoso podem ser altamente citotóxicos para as células em cultura e, portanto, uma resposta inflamatória pulpar deve ser considerada durante a aplicação clínica de adesivos dentinários.

The purpose of this study was to evaluate the potential cytotoxicity of Adper Single Bond 2 (SB) simplified etch-and-rinse adhesive system in alveolar macrophage cultures, as a function of the post-polymerization time and duration of immersion in the culture medium for preparation of extracts, by observing the levels of nitric oxide (NO) release and cell survival rate (MTT assay). Wistar rat alveolar macrophages were exposed to 200 μL of extracts obtained from 24- or 72-h immersion of adhesive samples in culture medium (RPMI), immediately or 24 h after polymerization. Fresh RPMI and E. coli lipopolysaccharides were used as negative and positive controls, respectively. The cells were placed in a humidified incubator for 24 h. The results were analyzed by the Student's-t test (α=5%). The amount of NO produced and viable cells were significantly different (p<0.05) between the experimental and the control groups, showing that, irrespective of the post-polymerization time and duration of immersion in the culture medium, the adhesive system caused intense cytotoxicity to the macrophages. The cytotoxic effects were not statistically different (p<0.05) among the experimental groups. In conclusion, chemical components released from SB in aqueous environment were highly toxic to cell culture and thus an inflammatory pulpal response should be considered during the clinical application of dental adhesives.