Iron supplementation reduces the erosive potential of a cola drink on enamel and dentin in situ

Iron has been suggested to reduce the erosive potential of cola drinks in vitro.OBJECTIVE: The aim of this study was to evaluate in situ the effect of ferrous sulfate supplementation on the inhibition of the erosion caused by a cola drink. MATERIAL AND METHODS: Ten adult volunteers participated in a crossover protocol conducted in two phases of 5 days, separated by a washout period of 7 days. In each phase, they wore palatal devices containing two human enamel and two human dentin blocks. The volunteers immersed the devices for 5 min in 150 mL of cola drink (Coca-ColaTM, pH 2.6), containing ferrous sulfate (10 mmol/L) or not (control), 4 times per day. The effect of ferrous sulfate on the inhibition of erosion was evaluated by profilometry (wear). Data were analyzed by paired t tests (

Autologous platelet concentrates for facial rejuvenation

Autologous platelet concentrates (APCs) are promising therapeutic agents in facial rejuvenation since they are a great source of cytokines, growth factors and other biologically active substances. Obtained from the patient’s blood, they have the advantages of reducing immunological reactions, making the procedure safer, well tolerated, with minimal adverse effects and lower cost. Currently, they are used for facial rejuvenation both in combination with microneedling and in mesotherapy techniques, as well as to treat facial acne scars, melasma and wounds after laser ablative treatments. This review summarizes current knowledge on the use of APCs, ranging from basic concepts related to their composition and mechanisms of action to up-to-date information on their clinical efficacy. Methodology: MEDLINE (PubMed) was searched from inception through 2021 for English language publications on APCs for facial rejuvenation. Results: A total of 100 files were found. Based on the available literature, APCs for skin rejuvenation are safe and well tolerated. The most studied product is the first-generation material, platelet-rich plasma (PRP). Conclusions: The results are in general favorable, but the quality of the studies is low. The second and third generation products, platelet-rich fibrin (PRF) and injectable platelet-rich fibrin (i-PRF), respectively, are easier to be obtained and, at least in vitro , seem to induce greater collagen production than PRP, especially under lower relative centrifugation forces, but to date only a few clinical trials evaluating these products exist. More high-quality trials with appropriate follow-up are necessary to provide adequate evidence that may help to improve the treatment regimens with APCs. Many aspects should be considered when designing clinical trials to evaluate APCs, such as the patients’ characteristics that best predict a favorable response, the optimal number of sessions and the interval between them, the characteristics of the studies and the development of better instruments to evaluate skin aging

Effect of one-bottle adhesive systems on the fluoride release of a resin-modified glass ionomer

A dhesive systems associated to resin-modified glass ionomer cements are employed for the achievement of a higher bond strength to dentin. Despite this benefit, other properties should not be damaged. This study aimed at evaluating the short-time fluoride release of a resin-modified glass ionomer cement coated with two one-bottle adhesive systems in a pH cycling system. Four combinations were investigated: G1: Vitremer (V); G2: Vitremer + Primer (VP); G3: Vitremer + Single Bond (VSB) and G4: Vitremer + Prime & Bond 2.1 (VPB). SB is a fluoride-free and PB is a fluoride-containing system. After preparation of the Vitremer specimens, two coats of the selected adhesive system were carefully applied and light-cured. Specimens were immersed in demineralizing solution for 6 hours followed by immersion in remineralizing solution for 18 hours, totalizing the 15-day cycle. All groups released fluoride in a similar pattern, with a greater release in the beginning and decreasing with time. VP showed the greatest fluoride release, followed by V, with no statistical difference. VSB and VPB released less fluoride compared to V and VP, with statistical difference. Regardless the one-bottle adhesive system, application of coating decreased the fluoride release from the resin-modified glass ionomer cements. This suggests that this combination would reduce the beneficial effect of the restorative material to the walls around the restoration.Sistemas adesivos são associados aos cimentos de ionômero de vidro modificados por resina para a obtenção de maior resistência adesiva à dentina. Apesar deste benefício, outras propriedades não devem ser prejudicadas. Este estudo se propôs a avaliar a liberação de flúor a curto prazo de um cimento de ionômero de vidro modificado por resina coberto com dois diferentes sistemas adesivos em um modelo de ciclagem de pH. Quatro associações foram testadas: G1: Vitremer (V); G2: Vitremer + Primer (VP); G3: Vitremer + Single Bond (VSB) and G4: Vitremer + Prime & Bond 2.1 (VPB). SB é um sistema sem flúor e PB contém flúor. Após a confecção das amostras de Vitremer, duas camadas de cada sistema selecionado foram aplicadas e fotopolimerizadas. Em seguida, as amostras foram imersas em solução desmineralizante por 6 horas, seguida da imersão em solução remineralizante por 18 horas, totalizando 15 dias de ciclagem. Todos os grupos liberaram flúor sob o mesmo padrão, apresentando maior liberação inicial e decrescendo ao longo do tempo. VP apresentou a maior liberação de flúor, seguida de V, sem diferença estatística. VSB and VPB liberaram menor quantidade de flúor em relação a V e VP, com diferenças estatisticamente significantes. Independentemente do sistema adesivo de frasco único, houve redução da liberação de flúor pelo cimento de ionômero de vidro modificado por resina. Isto sugere que esta associação poderia reduzir o efeito benéfico do material restaurador em torno da restauração

Censura, distanciamento e aproximações: a cobertura sobre o pasquim no jornal norte-americano The New York Times

Brazilian journalism history during the civil-military dictatorship has been enriched as new historical sources are revealed and analyzed. This article aims to situate the foreign perception of the North American newspaper The New York Times about O Pasquim during censorship, between 1969 and 1975, when it was published five stories about the brazilian newspaper, and to discuss the newsworthiness criteria of the north-american newspaper about censorship in brazilian press as well as how they have represented O Pasquim and the relationship between state politics and cultural movements in the United States in one of the most important newspaper in the world.A história do jornalismo brasileiro durante a ditadura civil-militar vem sendo enriquecida à medida que novas fontes historiográficas são reveladas e analisadas. O objetivo deste artigo é situar o olhar estrangeiro do jornal norte-americano The New York Times sobre a publicação O Pasquim durante o período da censura, entre 1969 e 1975, quando foram publicadas cinco reportagens sobre o periódico carioca. Partindo da análise crítica em relação ao jornal como fonte historiográfica, o objetivo aqui é discutir os critérios de noticiabilidade do jornal norte-americano sobre a censura aos impressos brasileiros, bem como sobre a forma com que o Pasquim foi representado, e a relação entre as políticas dos governantes, os movimentos culturais nos Estados Unidos com o conteúdo publicado em um dos jornais mais importantes do mundo

Saliva and dental erosion

Dental erosion is a multifactorial condition. The consideration of chemical, biological and behavioral factors is fundamental for its prevention and therapy. Among the biological factors, saliva is one of the most important parameters in the protection against erosive wear. Objective: This review discusses the role of salivary factors on the development of dental erosion. Material and Methods: A search was undertaken on MeDLINe website for papers from 1969 to 2010. The keywords used in the research were "saliva", "acquired pellicle", "salivary flow", "salivary buffering capacity" and "dental erosion". Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. Results: Several characteristics and properties of saliva play an important role in dental erosion. Salivary clearance gradually eliminates the acids through swallowing and saliva presents buffering capacity causing neutralization and buffering of dietary acids. Salivary flow allows dilution of the acids. In addition, saliva is supersaturated with respect to tooth mineral, providing calcium, phosphate and fluoride necessary for remineralization after an erosive challenge. Furthermore, many proteins present in saliva and acquired pellicle play an important role in dental erosion. Conclusions: Saliva is the most important biological factor affecting the progression of dental erosion. Knowledge of its components and properties involved in this protective role can drive the development of preventive measures targeting to enhance its known beneficial effects

Optimizing the formation of the acquired enamel pellicle in vitro for proteomic analysis

Saliva is the major contributor for the protein composition of the acquired enamel pellicle (AEP), a bacteria-free organic layer formed by the selective adsorption of salivary proteins on the surface of the enamel. However, the amount of proteins that can be recovered is even smaller under in vitro condition, due to the absence of continuous salivary flow. Objective: This study developed an in vitro AEP protocol for proteomics analysis using a new formation technique with different collection solutions. Methodology: 432 bovine enamel specimens were prepared (4x4 mm) and divided into four groups (n=108). Unstimulated saliva was provided by nine subjects. The new AEP formation technique was based on saliva resupply by a new one every 30 min within 120 minutes at 37ºC under agitation. AEP was collected using an electrode filter paper soaked in the collection solutions according with the group: 1) 3% citric acid (CA); 2) 0.5% sodium dodecyl sulfate (SDS); 3) CA followed by SDS (CA+SDS); 4) SDS followed by CA (SDS+CA). The pellicles collected were processed for analysis through LC-ESI-MS/MS technique. Results: A total of 55 proteins were identified. The total numbers of proteins identified in each group were 40, 21, 28 and 41 for the groups CA, SDS, CA+SDS and SDS+CA, respectively. Twenty-three typical AEP proteins were identified in all groups, but Mucin was only found in CA and CA+SDS, while three types of PRP were not found in the SDS group. Moreover, a typical enamel protein, Enamelin, was identified in the CA+SDS group only. Conclusion: The new technique of the in vitro AEP formation through saliva replacement was essential for a higher number of the proteins identified. In addition, considering practicality, quantity and quality of identified proteins, citric acid seems to be the best solution to be used for collection of AEP proteins

Incorporação de flúor ao esmalte dentário após o uso de dentifrício fluoretado, precedido ou não por bochecho com solução de CaCl2

INTRODUCTION: The use of a calcium solution previously to brushing could favor the remineralization and the fluoride (F) uptake in dental enamel. OBJECTIVE: This study evaluated the F in dental enamel after using a F dentifrice, preceded or not by a rinse with a CaCl2 solution. METHODS: Ten subjects (18-30 years) participated in a double-blind, cross-over protocol. Enamel biopsy and 3 min saliva samples were obtained at baseline and after brushing (1.5 g Crest®, 1,000 ppm F as NaF), preceded by a rinse with 10 mL of 20 mM CaCl2 50 mM acetate pH 7.2 or deionized water, for 1 min, followed by a 15 mL water rinse for 5 sec. Biopsies were made before the rinses and after 8-15 and 120 min. Saliva samples were collected before the rinses and after 4, 15, 30, 60 and 120 min. F concentration in enamel biopsies was analyzed with the F electrode (Orion 9409) and a miniature calomel reference electrode, while phosphorus concentration was analyzed by spectrophotometry. Saliva samples were analyzed for F with the electrode (Orion 9609) by the direct method. The data were analyzed by ANOVA and Tukey test (pINTRODUÇÃO: O uso de uma solução de cálcio previamente à escovação com dentifrício fluoretado, poderia favorecer a remineralização e a incorporação de flúor ao esmalte dentário. OBJETIVOS: Este estudo avaliou a concentração de flúor no esmalte dentário após o uso de dentifrício fluoretado, precedido ou não por bochecho com solução de CaCl2. MÉTODOS: Dez voluntários (18-30 anos) participaram deste estudo duplo cego e cruzado. Biópsias de esmalte e coletas de saliva de 3 min foram feitas no baseline e após a escovação com dentifrício (1,5g Crest®, 1000 ppm F, NaF), precedida por bochecho com 10mL de CaCl2 20mM, acetato 50mM, pH 7,2 ou água deionizada, durante 1 min, seguido de bochecho com 15mL de água deionizada por 5s. As biópsias foram feitas antes do bochecho e após 8-15 e 120 min. Amostras de saliva foram coletadas antes do bochecho e após 4, 15, 30, 60 e 120 min. A concentração de flúor nas biópsias de esmalte foi analisada com eletrodo para flúor (Orion 9409) e um microeletrodo calomelano de referência, enquanto a concentração de fósforo foi analisada por espectrometria. As amostras de saliva foram analisadas para flúor com o eletrodo (Orion 9609) pelo método direto. Os dados foram analisados por ANOVA e teste de Tukey (

Plasma como um indicador dos níveis de flúor no osso em ratos expostos cronicamente ao flúor

OBJECTIVE: This study evaluated the use of plasma, bone surface (periosteal) and whole bone as biomarkers of chronic fluoride (F) exposure. METHODS: Forty male Wistar rats were assigned to 4 groups (n=10/gr) that differed according to the F concentration they received in the drinking water. Groups 1, 2, 3 and 4 received water containing 0 (control), 5, 15, and 50 mg F/L, respectively. The rats were killed at 120 days of age. Plasma and femur were collected and analyzed for fluoride with the ion specific electrode by the direct method or after hexamethyldisiloxane-facilitated diffusion. Data were tested for statistically significant differences by ANOVA and linear regression (pOBJETIVOS: Este estudo avaliou o uso do plasma, superfície óssea e osso total como biomarcadores da exposição crônica ao flúor em ratos. MÉTODOS: Quarenta ratos Wistar machos foram divididos em 4 grupos (n=10/gr) que diferiram de acordo com a concentração de flúor presente na água de beber. Os grupos 1, 2, 3 e 4 receberam água contendo 0, 5, 15 e 50 mg F/L, respectivamente. Os ratos foram mortos ao completarem 120 dias. O plasma e os fêmures foram coletados e a concentração de flúor foi analisada com um eletrodo específico pelo método direto para a superfície do fêmur e após difusão facilitada por HMDS para o osso total e o plasma. Os dados foram analisados por ANOVA e regressão linear (