Effect of Toothpaste Fluoride Concentration on Color Stability of Resin Composites: An In Vitro Study

ABSTRACT Objective: To investigate the effects of two different dentifrice fluoride concentrations on the color stability of the composite. Material and Methods: Twenty-seven specimens (2×4×5 mm) each of microfilled (Gradia, GC, Japan) and nanohybrid (Grandio, VOCO, Germany) composites were prepared. The specimens were randomly divided into six groups (control, Fluoflor caries protection toothpaste with 1450ppm Fluoride (EXW, France), and Fluoflor kids toothpaste with 500ppm Fluoride (EXW, France) (n = 9). The specimens were immersed in a mixture of artificial saliva and toothpaste in a ratio of 1:3 and applied for 60 seconds every 12 hours for 42 days. The control samples were incubated in artificial saliva at 37°C. Primary and secondary color measurements were performed using color parameters (L∗a∗b) with a spectrophotoshade (MHT Optic Research AG, Niederhasli, Switzerland). Data were analyzed using a two-way analysis of variance at a significance level of 0.05. Results: According to the two-way ANOVA analysis, there was no significant difference in color change between the composites and no difference in the level of discoloration between different fluoride concentrations(p>0.05). Also, None of the dentifrices caused clinically significant color changes(∆E˂3.3). Conclusion: No clinically unacceptable color changes were observed in the microfilled and nanofilled composites with different concentrations of fluoride toothpaste.

Fluoride in Bottled Waters Consumed in Northeastern Brazil

ABSTRACT Objective: To assess the fluoride concentration of bottled waters from municipalities in northeastern Brazil. Material and Methods: Bottled mineral waters were purchased in two periods at different commercial places of four large municipalities (João Pessoa, Campina Grande, Patos, and Cajazeiras) in the Paraíba state. The municipalities selected to present the following annual average temperature: João Pessoa 26.5 °C, Campina Grande 23.3 °C, Patos and Cajazeiras 27.5 °C. Fluoride concentration was determined using a combined ion-specific electrode. Readings (in mV) were conducted in triplicates for each standard solution and converted into fluoride concentration (mg F/L) using the Excel® software. Results: A total of 72 samples from six brands of bottled water were analyzed. The fluoride concentrations of all samples were low (0.11-0.21mg/L) but higher than those reported on the label and varied among different batches of the same brand. Conclusion: The fluoride levels in bottled water vary among brands, and these actual values are not stated in the labels.

Spatial correlation between the prevalence of dental fluorosis and the chemical elemental composition of drinking water sources in a typical coal-fired pollution fluorosis area / 中华流行病学杂志

Objective: To investigate the spatial distribution characteristics and correlation between the prevalence of dental fluorosis and the chemical elemental composition of drinking water sources in coal-fired fluorosis areas. Methods: Based on the survey data on the prevalence of dental fluorosis at CDC in Guizhou Province in 2022, 274 original surface drinking water sources were collected in typical coal-fired fluorosis areas, and fluoride (F), calcium (Ca), magnesium (Mg), aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), molybdenum (Mo), cadmium (Cd), barium (Ba), lead (Pb) 17 elements; apply Moran's I index, Getis-Ord Gi* hotspot analysis of the global spatial autocorrelation of chemical elements in drinking water and the degree of aggregation of each element on the local area, and correlation analysis with the prevalence of dental fluorosis in the region. Results: Except for Cu, Zn, and Cd, global spatial autocorrelation Moran's I was negative, and all other elements were positive. F, Ca, Al, Ti, As, Mo, Cd, and Cu elements showed high values of aggregation in the southeastern low-altitude area; Mg, Ba, Pb, Cr, Mn, and Fe elements were mainly aggregated in the central altitude terrain transition area, Zn and Se elements in water sources are significantly positively correlated with the prevalence of dental fluorosis (P<0.05). In contrast, F, Mg, Al, Ti, As, Mo, Cd, Ba, and Pb elements negatively correlate (P<0.05). Elements in the central region were high-high aggregation, as a hot spot aggregation area with high disease incidence, while F, Al, Mn, Mo, Cd, and Ba elements in the western region were low-low aggregation, as a cold spot aggregation area with a low incidence of fluorosis. Conclusions: The risk of population fluoride exposure in surface drinking water sources is shallow. However, the chemical element content of drinking water sources in coal-fired polluted endemic fluorosis areas has prominent spatial geographical distribution characteristics. There is a significant spatial aggregation effect with the prevalence of dental fluorosis, which may play a synergistic or antagonistic effect on the occurrence and prevalence of dental fluorosis.

Clinical features of oral management to oral complications of Sjögren's syndrome / 北京大学学报(医学版)

OBJECTIVE@#To understand the clinical characteristics about sequence diagnosis and treatment of oral complications in patients with Sjögren's syndrome (SS) through retrospective analysis, and to provide some guidance for clinical work.@*METHODS@#Some SS patients who underwent oral sequence management in the Department of General Dentistry, Peking University School and Hospital of Stomatology from January 2015 to September 2021 were enrolled. For the SS patients included in this study, a comprehensive oral examination was performed, including parotid region examination, oral mucosal exa-mination, dentition examination, dental examination, periodontal examination, unstimulated salivary flow rate, Candida infection and radiological imaging examination. According to the examination results, the patients were given fluoride application, antifungal treatment, root canal therapy, direct filling repair, and indirect repair treatment in sequence and the results recorded.@*RESULTS@#A total of 9 patients with SS, with 4 primary SS patients (pSS) and 5 secondary SS patients (sSS) were enrolled in the study. For all the 9 patients, the average age was (49.2±16.2) years and the median xerostomia duration 5 years. The unstimulated salivary flow rate of the 9 patients was all less than 1 mL/10 min. Eight of the 9 cases was diagnosed as oral Candidiasis, with positive salivary Candida culture result (>200 cfu/mL), and 1 of the 9 cases was not. The average decay, missing, filling teeth (DMFT) was 24.8±4.2; the average decay, missing, filling tooth surfaces (DMFS) was 59.2±21.9, the average incisal caries was 2.5±1.3, and the average number of crown restorations at baseline was 4.5±3.6. All the 9 SS patients were applied with topical fluoride usage, and 8 were prescribed with antifungal treatment. One sSS patient was conducted with filling restoration treatment, one pSS patient was conducted with full mouth rehabilitation, and the remaining 7 patients were conducted with direct filling combined with fixed repair treatment. The average 3.2 full crown restorations in 6 patients had to be removed and restored because of secondary caries, and 3 of the 9 patients underwent implant denture restorations finally.@*CONCLUSION@#Management of oral complications in SS patients needs to be carried out in sequence. A comprehensive examination and diagnosis should be carried out first, followed by infection control, and then restoration of oral function at last.

Glutathione S-transferase genetic polymorphisms and fluoride-induced reproductive toxicity in men with idiopathic infertility / 亚洲男科学杂志(英文版)

Male infertility caused by idiopathic oligoasthenospermia (OAT) is known as idiopathic male infertility. Glutathione S-transferase (GST) and fluoride may play important roles in idiopathic male infertility, but their effects are still unknown. Our study examined the relationship between GST polymorphisms and fluoride-induced toxicity in idiopathic male infertility and determined the underlying mechanism. Sperm, blood, and urine samples were collected from 560 males. Fluoride levels were measured by a highly selective electrode method, and GST genotypes were identified using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP). Semen parameters, DNA fragmentation index (DFI), mitochondrial membrane potential (MMP), and oxidative stress (OS) biomarkers were statistically assessed at the P < 0.05 level. Compared with healthy fertile group, semen parameters, fluoride levels, OS biomarkers, sex hormone levels, and MMP and DFI levels were lower in the idiopathic male infertility group. For glutathione S-transferase M1 (GSTM1[-]) and glutathione S-transferase T1 (GSTT1[-]) or glutathione S-transferase P1 (GSTP1) mutant genotypes, levels of semen fluoride, OS, MMP, and DFI were considerably higher, and the mean levels of sperm parameters and testosterone were statistically significant in GSTM1(+), GSTT1(+), and GSTP1 wild-type genotypes. Both semen and blood fluoride levels were associated with oxidative stress in idiopathic male infertility patients. Elevated fluoride in semen with the genotypes listed above was linked to reproductive quality in idiopathic male infertility patients. In conclusion, GST polymorphisms and fluorine may have an indicative relationship between reproductive quality and sex hormone levels, and OS participates in the development of idiopathic male infertility.

Correlation analysis and benchmark dose study on bone metabolic biochemical index of low doses of exposed hydrogen fluoride workers / 中华劳动卫生职业病杂志

Objective: To analyze correlation of occupational hydrogen fluoride exposure to low doses of bone metabolism index through occupational epidemiological investigation and benchmark dose calculation. Methods: In May 2021, using cluster sampling method, 237 workers exposed to hydrogen fluoride in a company were selected as the contact group, and 83 workers not exposed to hydrogen fluoride in an electronics production company were selected as the control group. The external exposure dose and urinary fluoride concentration, blood and urine biochemical indicators of the workers was measured.The relationship between external dose and internal dose of hydrogen fluoride was analyzed. The external dose, urinary fluoride was used as exposure biomarkers, while serum osteocalcin (BGP), serum alkaline phosphatase (AKP) and urinary hydroxyproline (HYP) were used as effect biomarkers for bone metabolism of hydrogen fluoride exposure. The benchmark dose calculation software (BMDS1.3.2) was used to calculate benchmark dose (BMD) . Results: Urine fluoride concentration in the contact group was correlated with creatinine-adjusted urine fluoride concentration (r=0.69, P=0.001). There was no significant correlation between the external dose of hydrogen fluoride and urine fluoride in the contact group (r=0.03, P=0.132). The concentrations of urine fluoride in the contact group and the control group were (0.81±0.61) and (0.45±0.14) mg/L, respectively, and the difference between the two groups was statistically significant (t=5.01, P=0.025). Using BGP, AKP and HYP as effect indexes, the urinary BMDL-05 values were 1.28, 1.47 and 1.08 mg/L, respectively. Conclusion: Urinary fluoride can sensitively reflect the changes in the effect indexes of biochemical indexes of bone metabolism. BGP and HYP can be used as early sensitive effect indexes of occupational hydrogen fluoride exposure.

Mechanism of Learning and Memory Impairment in Rats Exposed to Arsenic and/or Fluoride Based on Microbiome and Metabolome / 生物医学与环境科学（英文）

OBJECTIVE@#Arsenic (As) and fluoride (F) are two of the most common elements contaminating groundwater resources. A growing number of studies have found that As and F can cause neurotoxicity in infants and children, leading to cognitive, learning, and memory impairments. However, early biomarkers of learning and memory impairment induced by As and/or F remain unclear. In the present study, the mechanisms by which As and/or F cause learning memory impairment are explored at the multi-omics level (microbiome and metabolome).@*METHODS@#We stablished an SD rats model exposed to arsenic and/or fluoride from intrauterine to adult period.@*RESULTS@#Arsenic and/fluoride exposed groups showed reduced neurobehavioral performance and lesions in the hippocampal CA1 region. 16S rRNA gene sequencing revealed that As and/or F exposure significantly altered the composition and diversity of the gut microbiome，featuring the Lachnospiraceae_NK4A136_group, Ruminococcus_1, Prevotellaceae_NK3B31_group, [Eubacterium]_xylanophilum_group. Metabolome analysis showed that As and/or F-induced learning and memory impairment may be related to tryptophan, lipoic acid, glutamate, gamma-aminobutyric acidergic (GABAergic) synapse, and arachidonic acid (AA) metabolism. The gut microbiota, metabolites, and learning memory indicators were significantly correlated.@*CONCLUSION@#Learning memory impairment triggered by As and/or F exposure may be mediated by different gut microbes and their associated metabolites.

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.

Dose-response relationship between toothpaste soluble fluoride absorbed in the gastrointestinal tract and saliva fluoride secretion

Aim: This study aimed to evaluate if there is a dose-response relationship between toothpaste chemically soluble fluoride absorbed in the gastrointestinal tract and fluoride secreted by saliva, giving support to the use of saliva as surrogate for plasma fluoride. Methods: A 4-phase single blind study was conducted, in which 10 participants were subjected in each phase to one of the assigned treatment groups: group I: fresh sample of a Na2FPO3/CaCO3-based toothpaste with 1,334 µg F/g of total soluble fluoride (TSF) and groups II­IV: aged samples of this toothpaste presenting TSF concentrations of 1,128, 808, and 687 µg F/g, respectively. In all phases, the participants ingested an amount of toothpaste equivalent to 70.0 µg F/Kg body weight, as total fluoride (TF). Saliva and blood samples were collected before (baseline) and up to 180 min after toothpaste ingestion as indicator of fluoride bioavailability. F concentration in saliva and blood plasma was determined with a fluoride ion-specific electrode. The areas under the curve (AUC) of F concentration versus time (AUC = ng F/mL × min) and the peaks of fluoride concentration (Cmax) in saliva and plasma were calculated. Results: A significant correlation between mg of TSF ingested and the AUC (r=0.47; p<0.01), and Cmax (r=0.59; p<0.01) in saliva was found; for TF, the correlation was not significant (p>0.05). In addition, the correlations between plasma and saliva fluoride concentrations were statistically significant for AUC (r=0.55; p<0.01) as for Cmax (r=0.68; p<0.01). Conclusion: The findings support that saliva can be used as a systemic biomarker of bioavailable fluoride present in Na2FPO3/CaCO3-based toothpaste

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.

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

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.

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 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.

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.

Efeito do trimetafosfato de sódio micro e nanoparticulado, associadas ou não ao fluoreto, sobre biofilmes mistos de Streptococcus mutans e Candida albicans: avaliação da composição orgânica e inorgânica / Effect of micro and nanoparticulate sodium trimetaphosphate, associated or not with fluoride, on mixed biofilms of Streptococcus mutans and Candida albicans: evaluation of organic and inorganic composition

Este estudo avaliou o efeito de nanopartículas de TMP (TMPn) sobre a composição inorgânica e componentes da matriz extracelular de biofilmes mistos de Streptococcus mutans e Candida albicans. Biofilmes de duas espécies de S. mutans e C. albicans foram cultivados em saliva artificial em placas de 6 poços e tratados três vezes (72, 78 e 96 h após o início de sua formação), por 1 minuto, com soluções contendo TMP microparticulado (TMPm) e TMPn nas concentrações de 1% e 3%, combinadas ou não com 1100 ppm F. Além disso, solução de 1100 ppm F (F) e saliva artificial (CTL) foram testadas como controles positivos e negativos, respectivamente. Após o último tratamento, a composição da matriz extracelular foi analisada em termos de proteína e carboidrato, e o pH e as concentrações de F, cálcio (Ca), fósforo (P) e P do TMP da biomassa e fluido do biofilme foram determinadas. Em outro conjunto de experimentos, após o último tratamento, os biofilmes foram expostos a uma solução de sacarose a 20%, e o pH e componentes inorgânicos dos biofilmes foram avaliados conforme mencionado acima. Os dados de proteínas e carboidratos foram submetidos a ANOVA a 1 critério, seguido pelo teste de Student-Newman-Keuls, enquanto os dados da composição inorgânica do biofilme foram submetidos a ANOVA a 2 critérios, seguido pelo teste de Fisher LSD (p< 0,05). Tratamentos com TMPn a 3% combinado com F levou a reduções significativamente maiores nas concentrações de carboidratos da matriz extracelular, maior concentração iônica de F no fluido, e um pH significativamente mais alto, se comparado a todos os outros grupos. Além disso, TMPn a 3% sem F levou a concentrações de P significativamente mais altas em comparação a todos os outros grupos, antes da exposição a sacarose. Conclui-se que o TMPn afetou a composição da matriz extracelular, o pH dos biofilmes analisados, além de interferir nos componentes inorgânicos dos biofilmes ao aumentar os níveis de fósforo no fluido do biofilme(AU)

This study evaluated the effect of TMP nanoparticles (nTMP) on the inorganic composition and extracellular matrix components of mixed biofilms of Streptococcus mutans and Candida albicans. Biofilms of two species of S. mutans and C. albicans were cultivated in artificial saliva in 6-well plates and treated three times (72, 78 and 96 h after the beginning of their formation), for 1 minute, with Solutions containing microparticulate TMP (TMPm) and TMPn at concentrations of 1% and 3%, combined or not with 1100 ppm F. In addition, 1100 ppm F (F) solution and artificial saliva (CTL) were tested as positive and negative controls, respectively. After the last treatment, the composition of the extracellular matrix was analyzed in terms of protein and carbohydrate, and the pH and concentrations of F, calcium (Ca), phosphorus (P) and P of the TMP of the biomass and biofilm fluid were determined. In another set of experiments, after the last treatment, the biofilms were exposed to a 20% sucrose solution, and the pH and inorganic components of the biofilms were evaluated as mentioned above. Protein and carbohydrate data were subjected to 1-way ANOVA, followed by the Student-Newman-Keuls test, while biofilm inorganic composition data were subjected to 2-way ANOVA, followed by the Fisher LSD test (p< 0 .05). Treatments with 3% nTMP combined with F led to significantly greater reductions in extracellular matrix carbohydrate concentrations, and significantly higher pH, compared to all other groups. In addition, 3% nTMP without F led to significantly higher P concentrations compared to all other groups before sucrose exposure. It is concluded that TMPn affected the composition of the extracellular matrix, the pH of the analyzed biofilms, in addition to interfering with the inorganic components of the biofilms by increasing phosphorus levels in the biofilm fluid(AU)

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)

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.