Dentin permeability after pretreatment with titanium tetrafluoride and self-etching or universal adhesive systems

Aim: To evaluate dentin permeability after pretreatment with 2.5% aqueous solution of titanium tetrafluoride (TiF4), followed by a self-etching universal adhesive system. Methods: Forty dentin discs (1.5 mm thick) were randomly divided into groups according to the application or non-application of a pretreatment, and the type of adhesive system to be tested (two-step self-etching/ Clearfil SE Bond/ Kuraray Medical, or universal adhesive system/ Single Bond Universal/ 3M ESPE). Both sides of the discs were conditioned with 37% phosphoric acid to remove the smear layer. The first hydraulic conductivity measurement (L1) was performed in a permeability machine, under 5 PSI pressure. The samples were sanded again to form a standardized smear layer. The teeth designated for pre-treatment with TiF4 received the TiF4 solutions applied actively for 60 seconds, and the adhesive systems were applied according to the manufacturer's instructions. Then, a new hydraulic conductivity measurement (L2) was performed for the purpose of calculating the hydraulic conductance at a later time, considering the water viscosity and the thickness of the specimen. The percentage (L) of dentin permeability after application of the adhesive system was obtained (L (%) = [(L1-L2) x100] / L1). The Mann-Whitney non-parametric test was applied. Results: There was no difference between the two adhesive systems, or between the groups with or without pretreatment, as regards dentin permeability (p>0.05). Conclusion: Pretreatment with 2.5% TiF4 did not influence dentin permeability, irrespective of the adhesive system used

A comparative study to evaluate the effects of antibiotics, plant extracts and fluoride-based toothpaste on the oral pathogens isolated from patients with gum diseases in Pakistan / Um estudo comparativo para avaliar os efeitos de antibióticos, extratos vegetais e creme dental à base de flúor sobre os patógenos orais isolados de pacientes com doenças gengivais no Paquistão

Abstract Oral diseases caused by various microorganisms are common around the world. Scientific research has now been focusing on novel medicines to overcome bacterial resistance and antibiotics side effects; therefore, the current study was designed to assess the efficacy of certain antibiotics, toothpaste, and medicinal plant extracts (Ajuga bracteosa and Curcuma longa) versus the bacterial pathogens isolated from the human oral cavity. A total of 130 samples were collected from Khyber Teaching Hospital Peshawar, Pakistan, among those 27 species isolated, and eight bacterial species were identified from the samples. Among all the bacterial species, Staphylococcus aureus (29.62%) and Proteus mirabilis (22.2%) were found to be more prevalent oral pathogens. In comparison, the least pervasive microbes were Proteus vulgaris, Shigella sonnei, Escherichia coli and Aeromonas hydrophila. The study also suggested that dental problems were more prevalent in males (41-50 years of age) than females. Among the eight antibiotics used in the study, the most promising results were shown by Foxicillin against A. hydrophila. The survey of TP1 revealed that it showed more potent antagonist activity against Proteus vulgaris as compared TP2 and TP3 that might be due to the high content of fluoride. The Curcuma longa showed more significant activity than Ajuga bracteosa (Stem, leaves and root) extracts. The data obtained through this study revealed that antibiotics were more effective for oral bacterial pathogens than toothpaste and plant extracts which showed moderate and low activity, respectively. Therefore, it is suggested that the active compounds in individual medicinal plants like Curcuma longa and Ajuga bracteosa could replace the antibiotics when used in daily routine as tooth cleansers or mouth rinses.

Resumo As doenças bucais causadas por vários microrganismos são comuns em todo o mundo. A pesquisa científica agora tem se concentrado em novos medicamentos para superar a resistência bacteriana e os efeitos colaterais dos antibióticos; portanto, o presente estudo foi desenhado para avaliar a eficácia de certos antibióticos, pasta de dente e extratos de plantas medicinais (Ajuga bracteosa e Curcuma longa) contra os patógenos bacterianos isolados da cavidade oral humana. No total, 130 amostras foram coletadas do Khyber Teaching Hospital Peshawar, Paquistão, entre essas, 27 espécies foram isoladas e oito espécies bacterianas foram identificadas a partir das amostras. Entre todas as espécies bacterianas, Staphylococcus aureus (29.62%) e Proteus mirabilis (22.2%) foram os patógenos orais mais prevalentes. Em comparação, os micróbios menos difundidos foram Proteus vulgaris, Shigella sonnei, Escherichia coli e Aeromonas hydrophila. O estudo também sugeriu que os problemas dentários eram mais prevalentes em homens (41-50 anos de idade) do que em mulheres. Entre os oito antibióticos usados ​​no estudo, os resultados mais promissores foram mostrados pelo Foxicillin contra A. hydrophila. A pesquisa de TP1 revelou que ele mostrou atividade antagonista mais potente contra Proteus vulgaris em comparação a TP2 e TP3, o que pode ser devido ao alto teor de flúor. A Curcuma longa apresentou atividade mais significativa em relação aos extratos de Ajuga bracteosa (caule, folhas e raiz). Os dados obtidos neste estudo revelaram que os antibióticos foram mais eficazes para os patógenos bacterianos orais do que os dentifrícios e os extratos vegetais que apresentaram atividade moderada e baixa, respectivamente. Portanto, sugere-se que os compostos ativos em plantas medicinais individuais como Curcuma longa e Ajuga bracteosa possam substituir os antibióticos quando usados ​​na rotina diária como limpadores de dentes ou enxaguatórios bucais.

Development and Validation of an Educational Comic Book for Guidance on the Safe Use of Fluoride Toothpaste by Children

ABSTRACT Objective: To describe the elaboration and content validation of a comic book for guidance on the safe use of fluoride toothpaste by children. Material and Methods: Study on the development of educational technology carried out in four phases: 1 - literature review and script; 2 - elaboration of the material (illustrations, layout and design), 3 - validation (Content Validity Index = CVI and Flesch Readability Index = FI), 4 - pilot test to legitimize the material with the target population. Thirty-one individuals participated in the validation, being 07 expert judges and 24 representatives of the lay population, responsible for the daily care of preschool and school-age children. Results: In the validation, CVI= 0.97 (97%), indicating high agreement of the judges' answers; and FI = 92%, which corresponds to "very easy to understand" reading. In the pilot test carried out with the lay population, the 3 assessment blocks had CVI=1.0 (100%). Conclusion: The comic book proved to be valid regarding appearance and content and can be used for health education activities for adults on the use of fluoride toothpaste for oral hygiene in children.

Potencial remineralizante del fluoruro diamino de plata al 38% en dentina de dientes temporales afectada por caries / Remineralizing potential of 38% silver diamine fluoride in dentin affected by dental caries

Introducción: la caries es una enfermedad compleja que afecta a cualquier edad. La prevalencia es mayor en la primera dentición, sobre todo en población con baja percepción económica. El fluoruro diamino de plata (FDP) al 38% ha sido utilizado como una alter- nativa de tratamiento para esta enfermedad. Funciona como una solución remineralizante y cariostática. Objetivo: evaluar el efecto remineralizante del FDP al 38% en dentina afectada por lesiones de caries en molares temporales. Material y métodos: estudio clínico, epidemiológico, descriptivo, longitudinal y experimental. Se llevó a cabo en molares de primera dentición de niños de tres a cinco años de edad. Los niños seleccionados tenían molares con lesiones cariosas dentinarias, Pitts las denomina D3. No se incluyeron niños con dientes que presentaron patologías pulpares irreversibles. La aplicación del FDP al 38% la efectuó un operador entrenado para esta finalidad. Se utilizaron los criterios de Nyvad para determinar el grado de dureza de la dentina y con ello deducir su remineraliza- ción. Se observó la permanencia de la remineralización efectuada por un periodo de cinco meses. Resultado y conclusión: el FDP es un compuesto eficaz en 91% de los casos en un periodo de cinco meses o más (AU)

Introduction: dental caries is a complex disease that affects any age. The prevalence is higher in primary dentition, especially in a population with low economic perception. 38% silver diamine fluoride (FDP) has been used as an alternative treatment for this disease. It works as a remineralizing and cariostatic solution. Objective: to evaluate the remineralizing effect of 38% FDP on dentin affected by dental caries, in temporary molars. Material and methods: clinical, epidemiological, descriptive, longitudinal and experimental study. It was carried out in temporary molars of children between three and five years of age. The selected children presented molars with dental carious lesions, Pitts calls them D3. Children with teeth that presented irreversible pulp pathologies were not included. The application of the FDP to 38% was carried out by an operator trained for this purpose. The Nyvad criteria were used to determine the degree of hardness of the dentin and thereby deduce its remineralization. The permanence of the remineralization carried out was observed for a period of five months. Result and conclusion: the FDP is an effective compound in 91% of the cases, in a period of five months or more (AU)

Fluoruros en agua de consumo al norte y occidente de México / Fluorides in water for consumption in northern and western Mexico

La cantidad de fluoruros en el agua en algunas regiones de México representa un problema de salud pública. El objetivo de este trabajo fue realizar una revisión sistemática de estudios originales que reportaran niveles de fluoruros en agua corriente y embotellada de la región norte y occidente de México. Esta revisión sistemática se elaboró utilizando el sistema PRISMA en las bases de datos de PubMed, Scopus, Medigraphic y Scielo. Se implementaron las palabras clave de fluoride OR fluorosis AND water AND Mexico, y se incluyeron y excluyeron registros de acuerdo con los criterios previamente establecidos. Fueron revisados aquellos artículos publicados entre el 1 de enero del 2010 y el 30 de marzo del 2021. Se identificaron 36 registros en total. La mayoría mostraban datos encontrados en la región occidente del país (n = 23) mientras que los restantes fueron realizados al norte. Ambas regiones se mostraron con rangos máximos y medias muestrales por encima de lo sugerido por la Organización Mundial de la Salud y los organismos reguladores nacionales. De acuerdo con los estudios aquí analizados en México, las regiones Norte y Occidente del país muestran una situación preocupante por los elevados niveles de fluoruros que reportan los autores en agua corriente y embotellada, los niveles se encuentran casi en su totalidad por encima de los recomendados a nivel nacional e internacional lo cual significa un problema de salud pública que requiere de atención.

The amount of fluoride in water in some regions of Mexico represents a public health problem. The aim of this study was to conduct a systematic review of original studies that report fluoride levels in tap and bottled water from the northern and western regions of Mexico. A systematic review was conducted using the PRISMA method in PubMed, Scopus, Medigraphic and Scielo databases. The keywords fluoride OR fluorosis AND water AND Mexico were used for the search and the records found were included and excluded according to the previous established criteria. We reviewed data in articles published between January 1st, 2010 and March 30th, 2021. We identified a total of 36 records. Most showed data found in the western region (n = 23), while the rest reported data found in the north. Both regions reported maximum and mean sample ranges above those suggested by the World Health Organization and national regulations. According to the analyzed data, in Mexico, the northern and western regions of the country show a concerning situation due to the high levels of fluoride reported by many authors in tap and bottled water. Almost all authors reported data above those recommended for national and international regulations, which represent an important public health problem that requires attention.

Fluoride toothpaste, sanitary surveillance and the SUS: the case of Manaus-AM, Brazil / Dentifrício fluoretado, vigilância sanitária e o SUS: o caso de Manaus-AM

ABSTRACT OBJECTIVE To determine the anticaries potential of toothpastes distributed by the primary health care public clinics (UBS) of Manaus, AM. METHODS Ninety-nine tubes of toothpaste from four commercial brands were collected from October 7, 2019 to October 11, 2019 in 16 UBS. They were assigned a code by brand and source UBS. According to the information on the packaging, the four brands and their batches were formulated with sodium monofluorophosphate (Na2FPO3) and most (91%) had calcium carbonate (CaCO3) as an abrasive. We determined the concentrations of total fluoride (TF = TSF + InsF) and total soluble fluoride (TSF = F ions- or FPO32-), to certify whether they were in compliance with resolution ANVISA RDC No. 530 (maximum of 1,500 ppm TF) and whether they had anticaries potential (minimum of 1,000 ppm TSF). The analyses were performed with a ion- specific electrode. RESULTS The concentrations (ppm F) of TF [mean; standard deviation (SD); n] found in toothpaste brands A (1,502.3; SD = 45.6; n = 33), B (1,135.5; SD = 52.7; n = 48) and D (936.8; SD = 20.5; N = 8) were close to those stated on the package, 1,500, 1,100 and 1,000 ppm F, respectively. In toothpaste C, we found a mean of 274.1 ppm (SD = 219.7; n = 10) of TF, which diverges from the declared concentration of 1,500 ppm F. In addition, the five tubes of lot no. 11681118 of toothpaste C did not contain fluoride. Regarding TSF, with the exception of toothpaste D (937.9; SD = 40.29), the others had a lower concentration than their respective TF. CONCLUSION We found serious problems of quantity and quality of fluoride in toothpaste distributed by the SUS in Manaus, which shows the need for surveillance of these products and confirms the urgency of revising resolution RDC No. 530.

RESUMO OBJETIVO Determinar o potencial anticárie dos dentifrícios distribuídos pelas unidades básicas de saúde (UBS) de Manaus-AM. MÉTODOS Noventa e nove bisnagas de dentifrícios de quatro marcas comerciais foram coletadas de 7 de outubro de 2019 a 11 de outubro de 2019 em 16 UBS, que foram codificados por marca e UBS de origem. De acordo com a embalagem, os dentifrícios das quatro marcas e seus lotes foram formulados com monofluorofosfato de sódio (Na2FPO3) e a maioria (91%) tinha carbonato de cálcio (CaCO3) como abrasivo. Foram determinadas as concentrações de fluoreto total (FT = FST + Fins) e de fluoreto solúvel total (FST = íons F- ou FPO32-), para certificar se atendiam à resolução ANVISA RDC Nº 530 (máximo de 1.500 ppm de FT) e se tinham potencial anticárie (mínimo de 1.000 ppm de FST). As análises foram feitas com eletrodo íon específico. RESULTADOS As concentrações (ppm F) de FT [média; desvio padrão (DP); n] encontradas nos dentifrícios A (1.502,3; DP = 45,6; n = 33), B (1.135,5; DP = 52,7; n = 48) e D (936,8; DP = 20,5; n = 8) foram próximas ao descrito na embalagem, 1.500, 1.100 e 1.000 ppm F, respectivamente. No dentifrício C, foi encontrada média de 274,1 ppm (DP = 219,7; n = 10) de FT, divergindo da concentração declarada de 1.500 ppm F. Em acréscimo, as cinco bisnagas do lote no 11681118 do dentifrício C não foram fluoretadas. Quanto ao FST, à exceção do dentifrício D (937,9; DP = 40,29), os demais apresentaram concentração inferior ao seu respectivo FT. CONCLUSÃO Observou-se problemas graves de quantidade e qualidade do fluoreto nos dentifrícios distribuídos pelo SUS em Manaus, mostrando a necessidade de vigilância desses produtos e ratificando a urgência da revisão da resolução ANVISA RDC Nº 530.

La concentración de fluoruro en agua potable y la fluorosis dental en niños / Fluoride concentration in drinking water in relation to dental fluorosis in children

Dental treatment is a highly sought-after but costly procedure in the world, so it is important to consider measures to prevent dental disease. Among the ways of prevention, drinking water fluoridation, which involves adding relevant amounts of fluoride to the water supply reaching communities, stands out. However, it is not clear whether there are enough researchers who have addressed the issue, or that their methodology has been adequate to provide alternatives to solve some conditions, such as dental fluorosis, which, in contrast, is manifested by excessive fluoride intake. The main objective was to explore and analyse the academic production on the concentration of fluoride present in drinking water in order to find a relationship with dental fluorosis in children. To this end, the PRISMA model was used as a starting point in order to carry out a systematic review of academic articles chosen according to selection criteria. These will be extracted from five databases, using a documentary-type methodology, whose data collection will be carried out in virtual environments. From this, it was concluded that the academic production includes the concentration of fluoride in drinking water as a means of prevention for dental pathologies; however, the levels of fluoride allowed in children should be known, as the excess of fluoride in the teeth causes dental fluorosis, which turns out to be the cause of psychological complexes in children due to an aesthetic issue.

El tratamiento dental es un procedimiento muy solicitado en el mundo, pero costoso de realizar; por lo que, es importante considerar medidas para prevenir enfermedades dentarias. Entre las formas de prevención, destaca la fluoración del agua potable, que implica añadir cantidades pertinentes de flúor al suministro de agua que llega a las comunidades. Sin embargo, no se precisa si existen suficientes investigadores que hayan abordado el tema, o que su metodología empleada haya sido la adecuada como para brindar alternativas para solucionar algunas afecciones, tales como la fluorosis dental que; en contraste, se manifiesta por la excesiva ingesta de flúor. El objetivo principal, realizar una exploración y análisis de la producción académica sobre la concentración de flúor presente en el agua potable con el fin de encontrar una relación con la fluorosis dental en niños. Para ello, se partió del modelo PRISMA con el fin de proceder una revisión sistemática de artículos académicos escogidos mediante criterios de selección. Estos serán extraídos de cinco bases de datos, valiéndose entonces, de una metodología de tipo documental, cuya recolección de datos se efectuará en entornos virtuales. A partir de ello, se concluyó que la producción académica incluye a la concentración del flúor en agua potable como un modo de prevención para patologías dentales; no obstante, se debe conocer los niveles de flúor permitido en los niños, pues el exceso de flúor en los dientes origina fluorosis dental, la cual resulta ser causante de complejos psicológicos en los niños debido a un tema estético.

Evaluation of desensitizing efficacy of nanohydroxyapatite on the treatment of dentine hypersensitivity following ultrasonic scaling: a randomized controlled trial / Avaliação da eficácia dessensibilizante da nanoidroxiapatita no tratamento da hipersensibilidade dentinária após raspagem ultrassônica: um ensaio clínico randomizado

Objective: This randomized controlled trial aimed to compare nanohydroxyapatite with fluoride on managing post ultrasonic scaling Dentine hypersensitivity (DH). Material and Methods: Thirty patients (aged 20-50 years) with post ultrasonic-scaling DH were included in this study. The sample was randomly divided into three equal groups of 60 teeth each: the first group received nanohydroxyapatite material, the second group received fluoride material and the third group received sterile water as a placebo (controls). The materials were applied once for each patient. All patients were instructed to rate the level of pain before treatment, and after 1 hour, 24 hours, 2 weeks and 1 month on the numerical rating scale (NRS). The Kruskal-Wallis test, Mann-Whitney tests, linear regression analysis were used for the statistical analysis. Significance level was set at 0.05. Results: Both nanohydroxyapatite and fluoride were successful in reducing pain associated with DH when compared with the placebo in subsequent follow-ups (p < 0.05). However, one-hour and one-day post application, nanohydroxyapatite could reduce hypersensitivity pain moreeffectively than fluoride (p < 0.05). Conclusion: Nanohydroxyapatite material was found to besignificantly more effective in reducing the DH that followed ultrasonic scaling one-hour and one-day post application as compared to fluoride and sterile water. Both fluoride and nanohydroxyapatite had similar effect on DH after two-weeks and one-month after application. (AU)

Objetivo: Este ensaio clínico randomizado teve como objetivo comparar a nano-hidroxiapatita com o flúor no manejo da hipersensibilidade dentinária (HD) pós-raspagem ultrassônica. Material e Métodos: Trinta pacientes (com idades entre 20-50 anos) com HD pós-raspagem ultrassônica foram incluídos neste estudo. A amostra foi dividida aleatoriamente em três grupos iguais com 60 dentes cada: o primeiro grupo recebeu material de nano-hidroxiapatita, o segundo grupo recebeu material de flúor e o terceiro grupo recebeu água esterilizada como placebo (controle). Os materiais foram aplicados uma vez para cada paciente. Todos os pacientes foram instruídos a avaliar o nível de dor antes do tratamento, e após 1 hora, 24 horas, 2 semanas e 1 mês na escala de avaliação numérica (NRS). Os testes de Kruskal-Wallis, Mann-Whitney e análise de regressão linear foram usados para a análise estatística. O nível de significância foi estabelecido em 0,05. Resultados: Tanto a nano- hidroxiapatita quanto o flúor foram bem-sucedidos na redução da dor associada à HD quando comparados ao placebo em acompanhamentos subsequentes (p <0,05). No entanto, 1 hora e 1 dia após a aplicação, a nano-hidroxiapatita pode reduzir a dor de hipersensibilidade de forma mais eficaz do que o flúor (p <0,05). Conclusão: O material da nano-hidroxiapatita foi significativamente mais eficaz na redução da HD que se seguiu à raspagem ultrassônica, 1 hora e 1 dia após a aplicação, em comparação com o flúor e a água estéril. Tanto o flúor, quanto a nano-hidroxiapatita apresentou efeito semelhante na HD após 2 semanas e 1 mês após a aplicação (AU)

Efficacy of 30% and 38% Silver Diamine Fluoride in Arresting Caries Lesions After Different Application Times: An in Vitro Study

Abstract Objective: To evaluate the efficacy of silver diamine fluoride (SDF) in arresting dentin caries lesions when applied under different concentrations and times. Material and Methods: Forty-two bovine blocks were selected and fixed in 24-well plates. Each well received a mixed bacterial inoculum added to the culture medium with 5% sucrose. The plates were incubated in microaerophilia (7 days) for caries formation, confirmed by micro-CT (M1). SDF was applied over the carious lesions for different times and concentrations (n=6): SDF 30% - immediate removal, 1 minute and 3 minutes; SDF 38%, - immediate removal, 1 minute and 3 minutes. The group without treatment was the control. Then, the samples were again scanned by micro-CT (M2) and submitted to a second cariogenic challenge for 21 days. Then, a final scan was performed (M3). Results: Mean pH at the culture medium and lesion depth were compared using Kruskal-Wallis and Wilcoxon tests. 38% SDF showed the lowest metabolic activity of the biofilm. All 38% groups and 30% 1 and 3 minutes did not show an increase in mean lesion depth comparing M3 with M1. However, only 30% 3 minutes and 38% 1 and 3 minutes showed a significant reduction of lesion depth. Conclusion: The minimum application time of 30% SDF to arrest dentin caries lesion was 1 minute, while 38% SDF arrested with application and immediate removal.

Fluoride Concentration in Public Water Supply in a City in the Amazon Region

Abstract Objective: To analyze the fluoride concentration in the public water supply in Manaus, Brazil. Material and Methods: Water samples were collected in 50 mL polyethylene bottles, identified, and labeled. The collection was performed from September 2016 to August 2018. For the selection of collection points, all neighborhoods of the city of Manaus, divided into four health districts (North, South, East, and West), were mapped. From each district, 30 samples were collected, totaling 120 monthly samples. Water samples were analyzed using an ion analyzer, ORION 720-A, and a specific electrode, ORION 96-09. The ion analyzer and electrode were calibrated in standard solutions. The levels were classified in intervals based on technical consensus to guide the health surveillance agencies. Results: Of the 2,874 water samples, 50.3% were within the recommended range, and 49.7% were inadequate, with 31.6% considered above the parameters and 18.1% below. Among the districts, the North had the highest percentages of unsatisfactory samples, resulting in limited action to prevent tooth decay. During the 24 months of analysis, there were large oscillations in the values in all four districts of Manaus. Conclusion: Results reinforce the importance of heterocontrol for the city to guarantee the effectiveness of this public health measure.

Research progress in ecological prevention of dental caries / 中华口腔医学杂志

Dental caries is one of the most common oral diseases around the world. Dental plaque attached to the surfaces of teeth is the main biological factor leading to caries. Although fluoride is still one of the most commonly used methods to prevent caries, with the change of epidemiological characteristics of caries and the update of the understanding of caries etiology, it is necessary to use other ecological methods such as antimicrobial peptides, arginine, probiotics and natural products, etc. to enhance the effect of fluoride in preventing dental caries. The present article reviews the research progress on the ecological approaches for caries prevention in recent years.

Study on the diffusion of hydrogen fluoride in an electrolytic fluoride plant based on CFD numerical simulation method / 中华劳动卫生职业病杂志

Objective: Using CFD technology to grasp the distribution and diffusion of hydrogen fluoride in an electrolytic fluorine plant, provide guidance and scientific basis for enterprises to carry out occupational health management in enterprises, install hazardous substance alarm devices, and protect workers' occupational health. Methods: In July 2019, the diffusion law of hydrogen fluoride gas produced in an electrolytic fluorine plant is selected as the research object. Through the establishment of models and grids, the Fluent numerical simulation method is finally used to simulate the diffusion and distribution of hydrogen fluoride gas under ventilation conditions. Results: The results showed that the average concentration of hydrogen fluoride was 0.045 mg/m(3) in the workplace, and the absorbed zone height (1.5 m) was 0.02 mg/m(3) in the inspection channel, which was in accordance with the national standard. However, there is eddy current above the electrolyzer near the inlet, may lead to the accumulation of hydrogen fluoride gas. Conclusion: The research of CFD numerical simulation method on the distribution and diffusion of hydrogen fluoride concentration in electrolytic fluorine plant can be applied to the prevention, control and management of occupational hazards in electrolytic fluorine plant.

Direct Synthesis of Bienzyme-like Carbide-derived Carbons via Mild Electrochemical Oxidation of Ti 3AlC 2 MAX / 生物医学与环境科学（英文）

Objective@#To develop effective alternatives to natural enzymes, it is crucial to develop nanozymes that are economical, resource efficient, and environmentally conscious. Carbon nanomaterials that have enzyme-like activities have been extensively developed as substitutes for traditional enzymes.@*Methods@#Carbide-derived carbons (CDCs) were directly synthesized via a one-step electrochemical method from a MAX precursor using an ammonium bifluoride electrolyte at ambient conditions. The CDCs were characterized by systematic techniques.@*Results@#CDCs showed bienzyme-like activities similar to that of peroxidase and superoxide dismutase. We systematically studied the dependence of CDC enzyme-like activity on different electrolytes and electrolysis times to confirm activity dependence on CDC content. Additionally, the synthesis mechanism and CDC applicability were elaborated and demonstrated, respectively.@*Conclusion@#The demonstrated synthesis strategy eliminates tedious intercalation and delamination centrifugation steps and avoids using high concentrations of HF, high temperatures, and halogen gases. This study paves the way for designing two-dimensional material-based nanocatalysts for nanoenzyme and other applications.

Research Trends on Preventive and Therapeutic Use of TIF4 for Dental Caries and Erosion

Abstract Objective: To evaluate TIF4 preventive and therapeutic use in caries and erosive lesions. Material and Methods: Searches were performed in six databases. Studies evaluating TiF4 use in vitro, in situ, and in vivo in caries and erosive lesions were included and imported into VantagePoint™ (VP). Data about publication year, authors, country, journal, study design, outcomes, TIF4 vehicles, application and intervention time, cariogenic challenge, erosive cycles, effects (positive/ negative /null) and approach (preventive/therapeutic) were analyzed through VP and Excel. Results: 93 published studies were included and an increase in publications was observed between 2010 and 2021. Forty-three authors published three or more articles, of which 67.4% were developed in Brazil and published in Caries Research (22.6%). 69.9% were in vitro studies with erosion assays (59.1%) and with preventive approaches (67.4%). The principal vehicle was a solution (69.9%) with a 1-min single application (58.0%) and with an intervention time of 5-7 days (22.6%). The principal cariogenic challenge in vitro was pH cycling (11.8%); in situ was sucrose + biofilm (6.2%); and in vivo, biofilm (6.2%). The most used erosive cycle was 4× per day in in vitro studies (20.4%) and 1× in vivo (2.1%). A positive effect was observed in prevention (41.9%) and treatment (24.7%) studies. Conclusion: TIF4 has shown a positive effect in prevention and therapeutic treatments for dental caries and erosion (AU).

In vitro determination of potentially bioavailable fluoride in diet and toothpaste after ingestion

Aim: To propose a new method to determine in vitro potentially bioavailable fluoride (F) in diet and toothpaste after ingestion. Methods: Diet samples (D) were obtained from 15 portions of a meal served to children in a day care centre. To simulate the ingestion of toothpaste during brushing after meals, a specific amount of toothpaste was added to the diet samples (D + T). F was determined in D and D + T after incubation in a solution that simulated "gastric juice" (0.01 M hydrochloric acid) at 37oC for 30, 60 and 120 min. Microdiffusion facilitated by HMDS was used to determine the total F concentrations in samples D and D + T. The analyses were performed using an ion specific electrode. Results: For D samples, incubation in "gastric juice" for 30, 60 and 120 min resulted in F concentrations (µg F/mL) of 0.75 ± 0.06c, 0.77 ± 0.07c and 0.91 ± 0.09b, corresponding to 75.3, 77.3 and 90.7% of the total F (1.02 ± 0.12a), respectively (p = 0.0001; ANOVA + Tukey). For D + T samples, these values of F concentrations (µg F/mL) were 2.55 ± 0.46b, 2.83 ± 0.44ab and 3.15 ± 0.37a, corresponding to 86.9, 94.8 and 106.7% of the total F (2.99 ± 0.34a), respectively (p = 0.0023; ANOVA + Tukey). Conclusion: Then, it can be concluded that the proposed method of "gastric juice" is a promising protocol for determining potentially bioavailable fluoride in the diet and toothpaste after ingestion. However, additional studies are desirable

In vitro effect of experimental nanocomposites solutions on the prevention of dental caries around orthodontic brackets

Abstract This study aimed to evaluate the in vitro effect of a single application of experimental nanocomposite solutions on the prevention of dental caries around orthodontic brackets. The specimens were exposed to mesoporous silica (MS) nanocomposites containing fluoride by association with titanium tetrafluoride (TiF4) or sodium fluoride (NaF). Nanocomposites also could contain calcium and groups were described as MSCaTiF4, MSTiF4, MSCaNaF, MSNaF, and controls (TiF4, and NaF). Specimens were subjected to the formation of a multispecies biofilm to generate a cariogenic challenge. After 24h, both pH and total soluble fluoride concentration of the culture medium were assessed. Mineral loss was evaluated by percentage of surface mineral loss (%SML), mineral volume variation (ΔZ) of inner enamel and polarized light microscopy (PL). Linear (Ra) and volumetric (Sa) surface roughness and scanning electronic microscopy (SEM) were used to assess enamel topography. Statistical analyses were conducted considering p<0.05. MSNaF had the highest value of culture medium pH after cariogenic challenge, similarly to MSTiF4. All nanocomposite solutions released less fluoride than their controls NaF and TiF4 (p<0.05). All nanocomposite solutions presented lower %SML compared to their respective control groups (p<0.05). Lower Ra, Sa and ΔZ were observed for experimental groups compared to TiF4 (p<0.05). The results were confirmed by PL and SEM analysis. The experimental nanocomposite solutions contributed for lower enamel demineralization around orthodontic brackets.

RESUMO Este estudo teve como objetivo avaliar o efeito in vitro de uma única aplicação de soluções experimentais de nanocompósitos na prevenção de cárie dentária em braquetes ortodônticos. Os espécimes foram expostos a nanocompósitos de sílica mesoporosa (MS) contendo fluoreto por associação com tetrafluoreto de titânio (TiF4) ou fluoreto de sódio (NaF). Os nanocompósitos também podem conter cálcio e os grupos foram descritos como MSCaTiF4, MSTiF4, MSCaNaF, MSNaF e controles (TiF4 e NaF). Os espécimes foram submetidos à formação de um biofilme multiespécie para gerar um desafio cariogênico. Após 24h, o pH e a concentração de flúor solúvel total do meio de cultura foram avaliados. A perda mineral foi avaliada pela porcentagem de perda mineral superficial (% SML), variação do volume mineral (ΔZ) do esmalte interno e microscopia de luz polarizada (PL). A rugosidade superficial linear (Ra) e volumétrica (Sa) e a microscopia eletrônica de varredura (MEV) foram utilizadas para avaliar a topografia do esmalte. As análises estatísticas foram realizadas considerando p <0,05. MSNaF apresentou o maior valor de pH do meio de cultura após o desafio cariogênico, semelhante ao MSTiF4. Todas as soluções de nanocompósitos liberaram menos flúor do que seus controles NaF e TiF4 (p <0,05). Todas as soluções de nanocompósitos apresentaram% SML menor em comparação com seus respectivos grupos de controle (p <0,05). Ra, Sa e ΔZ menores foram observados para os grupos experimentais em comparação ao TiF4 (p <0,05). Os resultados foram confirmados por análises PL e SEM. As soluções experimentais de nanocompósitos contribuíram para a menor desmineralização do esmalte ao redor dos braquetes ortodônticos.

Fluoride bioavailability on demineralized enamel by commercial mouth rinses

Abstract The ability of mouth rinses, available in the international market, to form reaction products on demineralized enamel (bioavailability test) was evaluated in vitro. Nine mouth rinses purchased in Chile were evaluated; eight formulated with NaF (one containing 100 µg F/mL and seven containing 226) and one with Na2FPO3 (226 µg F/mL as ion F). Demineralized enamel slabs (n=15 per mouth rinse) were sectioned; one half was subjected to the assigned mouth rinse treatment for 10 min and the other half was used to obtain baseline data. Loosely bound and firmly bound fluoride formed on enamel were determined with an ion-specific electrode and the values were expressed in µg F/cm2. The concentration of fluoride and the pH of the mouth rinses were previously determined. Concentrations of loosely bound and firmly bound fluoride formed on enamel were independently analyzed by ANOVA and Tukey's test (α=5%). The loosely bound and firmly bound fluoride concentrations (µg F/cm2) formed ranged from 3.2 to 36.2 and 0.4 to 1.7, respectively. Loosely bound fluoride formed on enamel was significantly more effective in discriminating the effect of different commercial mouth rinses than firmly bound fluoride. Mouth rinses with 226 ppm F as NaF and low pH presented significantly greater bioavailability of fluoride on enamel than those with higher pH or lower NaF concentration. The mouth rinse with Na2FPO3 showed low reactivity. Although further studies are necessary, the findings showed that commercial fluoride-containing mouth rinses have important variations in enamel fluoride bioavailability, which may result in differences on anticaries efficacy.

Resumo Os enxaguatórios bucais comerciais fluoretados diferem na concentração e tipo de sal de fluoreto, no pH e têm alguns ingredientes que podem interferir na reatividade do fluoreto com o esmalte desmineralizado. A capacidade de enxaguatórios bucais comerciais de formar produtos de reação em esmalte desmineralizado (teste de biodisponibilidade) foi avaliada in vitro. Nove enxaguatórios bucais adquiridos no Chile foram avaliados, oito formulados com NaF (um contendo 100 µg F/mL e sete contendo 226) e um com Na2FPO3 (226 µg F/mL como íon F). Os blocos de esmalte desmineralizados (n=15 por grupo) foram seccionados, uma metade foi submetida ao tratamento com o enxaguatório designado por 10 min e a outra metade foi usada para dados baseline. Fluoreto fracamente e firmemente ligados formados no esmalte foram determinados com um eletrodo íon-específico e os valores foram expressos em µg F /cm2. A concentração de fluoreto e o pH dos enxaguatórios foi previamente determinada. As concentrações de fluoreto tipo fluoreto fracamente ligado e fortemente ligado formadas no esmalte foram analisadas independentemente por ANOVA e teste de Tukey (α=5%). As concentrações de fluoreto fracamente ligado e fortemente ligado formados variaram de 3,2 a 36,2 e 0,4 a 1,7, respectivamente. O fluoreto fracamente ligado formado no esmalte foi significativamente mais eficaz para discriminar o efeito dos diferentes enxaguatórios bucais comerciais do que o fluoreto firmemente ligado. Enxaguatórios bucais com 226 ppm F na forma de NaF e baixo pH apresentaram significativamente maior biodisponibilidade de fluoreto no esmalte do que aqueles com maior pH ou menor concentração de NaF. O enxaguatório com Na2FPO3 apresentou reatividade muito baixa. Embora mais estudos sejam necessários, os resultados mostraram que os enxaguatórios bucais comerciais contendo fluoreto apresentam variações importantes na biodisponibilidade do fluoreto, o que poderia resultar em diferenças na eficácia anticárie.

Effect of fluoridated water on dental caries and fluorosis in schoolchildren who use fluoridated dentifrice

Abstract This cross-sectional study evaluated the prevalence and severity of dental caries and fluorosis in children and adolescents using fluoridated toothpaste, from areas with and without fluoridated water. Parents of 5-year-old children and 12-year-old adolescents from neighbourhoods that are supplied with and without fluoridated water answered questionnaires for determining socio-economic and demographic characteristics and habits related to oral health. The individuals were examined, and dental caries and fluorosis were measured by dmft/DMFT and TF indexes, respectively. Descriptive, bivariate and logistic regression analyses were performed (p < 0.05). Of 692 participants, 47.7% were 5-year-olds and 52.3% were 12-year-olds. The mean dmft/DMFT in the 5-year-olds/ 12-year-olds from Exposed and Not Exposed fluoridated water groups was 1.53 (± 2.47) and 3.54 (± 4.10) / 1.53 (± 1.81) and 3.54 (± 3.82), respectively. Children (OR = 2.86, 95% CI = 1.71-4.75) and adolescents (OR = 1.95, 95% CI = 1.24-3.05), who did not consume fluoridated water, had greater caries experience. Among adolescents, there was an association between fluoridated water and the prevalence of very mild/mild fluorosis (OR = 5.45, 95% CI: 3.23-9.19) and moderate fluorosis (OR = 11.11, 95% CI = 4.43-27.87). Children and adolescents, who consumed fluoridated water, presented lower prevalence and severity of dental caries compared to those who used only fluoridated toothpaste as the source of fluoride. There is an association between water fluoridation and very mild/mild and moderate fluorosis in adolescents.

Resumo Este estudo transversal avaliou a prevalência e severidade de cárie dentária e fluorose em crianças de 5 anos e adolescentes de 12 anos usuários de dentifrício fluoretado, em áreas com e sem água fluoretada. Os responsáveis pelas crianças e adolescentes responderam questionários para determinação de características socioeconômicas e demográficas e hábitos relacionados à saúde. Os indivíduos foram examinados e a cárie e a fluorose foram mensuradas pelos índices ceo-d / CPOD e TF, respectivamente. Foram realizadas análises descritivas, bivariadas e de regressão logística (p <0,05). Dos 692 participantes, 47,7% tinham 5 anos e 52,3% tinham 12 anos. A média de ceod / CPOD em crianças de 5/12 anos dos grupos de exposto e não exposto à água fluoretada foi 1,53 (± 2,47) e 3,54 (± 4,10) / 1,53 (± 1,81) e 3,54 (± 3,82), respectivamente. Crianças (OR = 2,86, IC 95% = 1,71-4,75) e adolescentes (OR = 1,95, IC 95% = 1,24-3,05) que não consumiram água fluoretada tiveram maior experiência de cárie. Entre os adolescentes, houve associação entre a água fluoretada e a prevalência de fluorose muito leve / leve (OR = 5,45, IC 95%: 3,23-9,19) e fluorose moderada (OR = 11,11, IC 95% = 4,43-27,87). Crianças e adolescentes que consumiram água fluoretada apresentaram menor prevalência e severidade de cárie dentária em comparação com aqueles que usaram apenas dentifrício fluoretado como fonte de flúor. Houve uma associação entre a fluoretação da água e fluorose muito leve / leve e moderada em adolescentes.

Fluoride bioavailability on demineralized enamel by commercial mouthrinses

Abstract The ability of mouthrinses, available in the international market, to form reaction products on demineralized enamel (bioavailability test) was evaluated in vitro. Nine mouthrinses purchased in Chile were evaluated; eight formulated with NaF (one containing 100 µg F/mL and seven containing 226) and one with Na2FPO3 (226 µg F/mL as ion FPO3 ). Demineralized enamel slabs (n=15 per mouthrinse) were sectioned; one half was subjected to the assigned mouthrinse treatment for 10 min and the other half was used to obtain baseline data. Loosely bound and firmly bound fluoride formed on enamel were determined with an ion-specific electrode and the values were expressed in µg F/cm2. The concentration of fluoride and the pH of the mouthrinses were previously determined. Concentrations of loosely bound and firmly bound fluoride formed on enamel were independently analyzed by ANOVA and Tukey's test (α=5%). The loosely bound and firmly bound fluoride concentrations formed ranged from 3.2 to 36.2 and 0.4 to 1.7, respectively. Loosely bound fluoride formed on enamel was significantly more effective in discriminating the effect of different commercial mouthrinses than firmly bound fluoride. Mouthrinses with 226 ppm F as NaF and low pH presented significantly greater bioavailability of fluoride on enamel than those with higher pH or lower NaF concentration. The mouthrinse with Na2FPO3 showed low reactivity. Although further studies are necessary, the findings showed that commercial fluoride-containing mouthrinses have important variations in enamel fluoride bioavailability, which may result in differences on anticaries efficacy.

Resumo Os enxaguatórios bucais comerciais fluoretados diferem na concentração e tipo de sal de fluoreto, no pH e têm alguns ingredientes que podem interferir na reatividade do fluoreto com o esmalte desmineralizado. A capacidade de enxaguatórios bucais comerciais de formar produtos de reação em esmalte desmineralizado (teste de biodisponibilidade) foi avaliada in vitro. Nove enxaguatórios bucais adquiridos no Chile foram avaliados, oito formulados com NaF (um contendo 100 µg F/mL e sete contendo 226) e um com Na2FPO3 (226 µg F/mL como íon F). Os blocos de esmalte desmineralizados (n=15 por grupo) foram seccionados, uma metade foi submetida ao tratamento com o enxaguatório designado por 10 min e a outra metade foi usada para dados baseline. Fluoreto fracamente e firmemente ligados formados no esmalte foram determinados com um eletrodo íonespecífico e os valores foram expressos em µg F /cm2. A concentração de fluoreto e o pH dos enxaguatórios foi previamente determinada. As concentrações de fluoreto tipo fluoreto fracamente ligado e fortemente ligado formadas no esmalte foram analisadas independentemente por ANOVA e teste de Tukey (α=5%). As concentrações de fluoreto fracamente ligado e fortemente ligado formados variaram de 3,2 a 36,2 e 0,4 a 1,7, respectivamente. O fluoreto fracamente ligado formado no esmalte foi significativamente mais eficaz para discriminar o efeito dos diferentes enxaguatórios bucais comerciais do que o fluoreto firmemente ligado. Enxaguatórios bucais com 226 ppm F na forma de NaF e baixo pH apresentaram significativamente maior biodisponibilidade de fluoreto no esmalte do que aqueles com maior pH ou menor concentração de NaF. O enxaguatório com Na2FPO3 apresentou reatividade muito baixa. Embora mais estudos sejam necessários, os resultados mostraram que os enxaguatórios bucais comerciais contendo fluoreto apresentam variações importantes na biodisponibilidade do fluoreto, o que poderia resultar em diferenças na eficácia anticárie

Cost-benefit analysis of drinking water fluoridation in 12-year-old children in the Biobío region, Chile / Análisis costo-ceneficio de la fluoración del agua potable en niños de12 años de la región del Biobío, Chile

Fluoridation has been shown to be an effective measure against caries in children. The present study evaluates the cost-benefit of the fluoridated water program for the reduction of dental caries in 12-year-old children in the Biobío Region, the only region in Chile that has not implemented this program. An economic cost-benefit evaluation was carried out, comparing two alternative interventions: non-fluoridated drinking water versus fluoridated drinking water. The prevalence of caries, direct and indirect costs of the treatments, the cost of implementing the programs and the benefits of both interventions were estimated. From this study it is concluded that the savings in oral health costs in 12-year-old children when using fluoridating drinking water in the Biobío region is significantly higher than the cost involved in implementing the water fluoridation program, resulting in total savings for the Chilean state of $129,861,645 (USD$ 152,833) as well as an estimated reduction of 15% in the history of caries in the study population.

Se ha demostrado que la fluoración es una medida efectiva contra disminución de la caries en la población infantil. La presente investigación buscó evaluar cual es el costo-beneficio del programa del agua fluorada para la disminución de caries dental en niños de 12 años de la Región del Biobío, única región de Chile que no adhiere a este programa. Se realizó una evaluación económica de costo-beneficio, comparando dos intervenciones alternativas: agua potable no fluorada versus agua potable fluorada. Para tal fin se estimó la prevalencia de caries, costos directos e indirectos de los tratamientos, el costo de implementación de los programas y el beneficio de ambas intervenciones. De este estudio se concluye que el ahorro en costos de salud bucal en niños de 12 años al fluorar el agua potable en la región del Biobío, es significativamente mayor al costo que implica la implementación del programa de fluoración de aguas, lográndose un ahorro total para el Estado de $129.861.645 (USD $152.833) así como una estimación de reducción del 15% en la historia de caries en la población de estudio.