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1.
BMC Oral Health ; 19(1): 119, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31215467

RESUMO

OBJECTIVES: Bioactive glasses which degrade in aqueous solutions may release bioactive ions such as fluoride (F-) and support fluoride bioavailability in saliva. We investigated how these effects would be apparent in an in vivo experimental trial after toothbrushing in comparison with sodium fluoride and amine fluoride. MATERIAL AND METHODS: In this single-center, randomized, parallel in vivo trial with a three strata block design, where healthy subjects were randomly assigned into three groups. Each group brushed their teeth either with fluoridated bioactive glass containing dentifrice, with a sodium fluoride (NaF) containing dentifrice or with amine fluoride (AmF) containing toothpaste. Saliva was collected time intervals before, immediately after, 30, 60 and 120 min after toothbrushing. Fluoride concentration was determined in supernatant saliva and salivary sediment using a fluoride ion selective electrode. The data were evaluated statistically using non-parametric tests. RESULTS: The increase of bioactive fluoride in supernatant saliva was higher after application of NaF or AmF compared to fluoridated bioactive glass. In salivary sediment bioavailability of fluoride lasted longer after application of fluoridated bioactive glass. CONCLUSIONS: Toothbrushing with the fluoride containing bioactive glass dentifrices had positive effects on the fluoride bioavailability within two hours. Fluoride containing bioactive glass represent a new area for investigation in caries prophylaxis. The bioactive potential impact on the tooth remineralization should be examined further. TRIAL REGISTRATION: DRKS00016038 .


Assuntos
Cariostáticos/análise , Cárie Dentária/prevenção & controle , Dentifrícios/química , Fluoretos/análise , Saliva/química , Fluoreto de Sódio/química , Escovação Dentária , Aminas , Disponibilidade Biológica , Humanos , Saliva/metabolismo , Fatores de Tempo
2.
Colloids Surf B Biointerfaces ; 181: 77-84, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31125921

RESUMO

The aim of the present study was to formulate toothpastes containing biosurfactants and either fungal chitosan or sodium fluoride and evaluate the cytotoxicity, antimicrobial action and inhibition potential against biofilm formed by Streptococcus mutans. Chitosan was extracted from the biomass of the fungus Mucorales. We tested biosurfactants produced by Pseudomonas aeruginosa UCP 0992 (PB), Bacillus metylotrophicus UCP 1616 (BB) and Candida bombicola URM 3718 (CB). Fractional inhibitory concentration analysis was performed to determine the type of interaction between the compounds. Six toothpaste were prepared, the active ingredients of which were the biosurfactants, chitosan or sodium fluoride. The cytotoxicity tests were performed using the 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay for the L929 (mouse fibroblast) and RAW 264.7 (mouse macrophage) cell lines. The toothpastes were tested with regard to pH, consistency and foaming capacity. The inhibition of biofilm was investigated by applying the toothpaste to biofilm formed in modified artificial saliva for 24 h at 37 °C in anaerobiosis. All substances had a minimum inhibitory concentration (MIC) for S. mutans. The combinations of CB and PB with chitosan had an additive effect against S. mutans, whereas BB combined with chitosan had an indifferent effect. The toothpastes were non-toxic. The formulations had pH around 9, spreading capacity between 8 and 17 mm and foaming capacity between 63 and 95%. All formulations inhibited the cellular viability of S. mutans in the biofilm, with similar results compared to the commercial toothpaste tested. The present results show that the formulations suggested are promising when compared to a commercial tooth paste.


Assuntos
Quitosana/farmacologia , Streptococcus mutans/efeitos dos fármacos , Tensoativos/farmacologia , Cremes Dentais/química , Cremes Dentais/farmacologia , Animais , Biofilmes/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Quitosana/isolamento & purificação , Fibroblastos/efeitos dos fármacos , Camundongos , Tamanho da Partícula , Células RAW 264.7 , Fluoreto de Sódio/química , Fluoreto de Sódio/isolamento & purificação , Fluoreto de Sódio/farmacologia , Propriedades de Superfície , Tensoativos/química , Tensoativos/isolamento & purificação , Cremes Dentais/isolamento & purificação
3.
Mater Sci Eng C Mater Biol Appl ; 99: 1067-1074, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889639

RESUMO

Using a facile hydrothermal procedure, hydrophilic NaYF4: Yb3+/Er3+ nanoparticles (NPs) have been prepared as lanthanide-doped upconversion (UC) materials exhibiting different morphologies, crystal phases and luminescence intensity. The upconversion nanoparticles (UCNP) were characterized by means of electron microscopy and spectroscopy, X-ray diffraction (XRD) and photoluminescence analysis. The molar concentration of reactants and volumes of NaF affect the shapes and uniformity of the synthesized NPs. These parameters also have influence on crystal phase and luminescence intensity of the NPs. Adjusting hydrothermal reaction time and dopant concentration also enable the synthesis of NPs with strong UC luminescence. The as-prepared UCNP showed cellular nontoxicity to HeLa cells, and thus they are capable as promising agents for biological imaging.


Assuntos
Monitoramento Ambiental/métodos , Érbio/química , Fluoretos/química , Luminescência , Nanopartículas/química , Temperatura , Água/química , Itérbio/química , Ítrio/química , Morte Celular , Células HeLa , Humanos , Íons , Nanopartículas/ultraestrutura , Tamanho da Partícula , Fluoreto de Sódio/química , Fatores de Tempo
4.
J Appl Oral Sci ; 27: e20180230, 2019 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-30810636

RESUMO

OBJECTIVES: To study the fluoride uptake and release properties of glass carbomer dental cements and compare them with those of conventional and resin-modified glass ionomers. MATERIALS AND METHODS: Three materials were used, as follows: glass carbomer (Glass Fill), conventional glass ionomer (Chemfil Rock) and resin-modified glass ionomer (Fuji II LC). For all materials, specimens (sets of six) were matured at room temperature for time intervals of 10 minutes, 1 hour and 6 weeks, then exposed to either deionized water or sodium fluoride solution (1000 ppm in fluoride) for 24 hours. Following this, all specimens were placed in deionized water for additional 24 hours and fluoride release was measured. RESULTS: Storage in water led to increase in mass in all cases due to water uptake, with uptake varying with maturing time and material type. Storage in aqueous NaF led to variable results. Glass carbomer showed mass losses at all maturing times, whereas the conventional glass ionomer gained mass for some maturing times, and the resin-modified glass ionomer gained mass for all maturing times. All materials released fluoride into deionized water, with glass carbomer showing the highest release. For both types of glass ionomer, uptake of fluoride led to enhanced fluoride release into deionized water. In contrast, uptake by glass carbomer did not lead to increased fluoride release, although it was substantially higher than the uptake by both types of glass ionomer. CONCLUSIONS: Glass carbomer resembles glass ionomer cements in its fluoride uptake behavior but differs when considering that its fluoride uptake does not lead to increased fluoride release.


Assuntos
Apatitas/química , Fluoretos/química , Cimentos de Ionômeros de Vidro/química , Cimentos de Resina/química , Silicatos de Alumínio/química , Análise de Variância , Teste de Materiais , Valores de Referência , Resinas Sintéticas/química , Fluoreto de Sódio/química , Fatores de Tempo , Água/química
5.
Braz Oral Res ; 33: e015, 2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-30758411

RESUMO

We assessed the effect of a new coating material based on resin-modified glass-ionomer with calcium (Ca) in inhibiting the demineralization of underlying and adjacent areas surrounding caries-like lesions in enamel. The measures used were surface hardness (SH) and cross-sectional hardness (CSH). Thirty-six bovine enamel specimens (3 × 6 × 2 mm) were randomly allocated into three groups (n = 12): No treatment (NT); resin-modified glass-ionomer with Ca (Clinpro XT Varnish, 3M ESPE) (CL), and fluoride varnish (Duraphat, Colgate) (DU). The specimens were subjected to alternated immersions in demineralizing (6 h) and remineralizing solutions (18 h) for 7 days. SH measurements were conducted at standard distances of 150, 300, and 450 µm from the treatment area. CSH evaluated the mean hardness profile over the depth of the enamel surface and at standard distances from the materials. The energy-dispersive X-ray spectroscopy analysis was conducted to evaluate the demineralization bands created on the sublayer by % of calcium (Ca), phosphorus (P), and fluoride (F). Ca/P weight ratio was also calculated. Based on SH and CSH measurements, there was no difference between groups at the distances 150 µm (p = 0.882), 300 µm (p = 0.995), and 450 µm (p = 0.998). Up to 50 µm depth (at 150 µm from the treatment area), CL showed better performance than DU ( p< 0.05). NT presented higher loss of Ca and P than CL and DU (p < 0.05). There was no significant difference in the % of F ion among the three groups. The new coating material was similar to F varnish in attenuating enamel demineralization.


Assuntos
Cálcio/química , Esmalte Dentário/efeitos dos fármacos , Cimentos de Ionômeros de Vidro/química , Cimentos de Resina/química , Desmineralização do Dente/prevenção & controle , Animais , Cariostáticos/química , Bovinos , Fluoretos Tópicos/química , Testes de Dureza , Concentração de Íons de Hidrogênio , Teste de Materiais , Distribuição Aleatória , Valores de Referência , Reprodutibilidade dos Testes , Fluoreto de Sódio/química , Espectrometria por Raios X , Propriedades de Superfície/efeitos dos fármacos , Fatores de Tempo
6.
Clin Oral Investig ; 23(10): 3713-3720, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30623309

RESUMO

OBJECTIVES: The aim of this study was to investigate the effect of a dentifrice that contains calcium silicate, sodium phosphate, and fluoride on erosive-abrasive enamel wear. MATERIAL AND METHODS: This randomized, single-blind in situ/ex vivo study was conducted with four crossover phases of 5 days (one group tested per phase). Bovine enamel blocks (n = 256) were allocated to 16 volunteers and 8 groups. The groups under study were test dentifrice, with calcium silicate, sodium phosphate, and 1450 ppm sodium monofluorophosphate; tin dentifrice, with 3500 ppm stannous chloride, 700 ppm amine fluoride, and 700 ppm sodium fluoride; conventional dentifrice, with 1450 ppm sodium monofluorophosphate; and control (deionized water). Half of the enamel blocks were subjected to erosion and the other half to erosion plus abrasion. The daily extraoral protocol consisted in four citric acid exposures (2 min) and two applications of dentifrice slurry on all blocks for 30 s; after, half of the blocks were brushed for 15 s. The response variable was enamel loss. Data were analyzed by two-way ANOVA and Fisher's test (p < 0.05). RESULTS: For erosion, the test dentifrice promoted less enamel loss than water (4.7 ± 3.1 and 5.8 ± 2.5 µm, respectively, p < 0.05), and did not differ from tin (4.8 ± 2.5 µm) and conventional (4.8 ± 1.4 µm) dentifrices (p > 0.05). However, the test dentifrice (7.7 ± 3.8 µm) promoted higher wear after erosive plus abrasive procedures than tin (5.4 ± 1.5 µm) and conventional (6.2 ± 1.7 µm, p < 0.05) dentifrices, and did not differ from water (6.9 ± 2.0 µm). CONCLUSIONS: The investigated dentifrice reduced enamel loss against acid challenge but had no effect against acid and brushing challenge. CLINICAL RELEVANCE: Little is known regarding the preventive effect of dentifrices indicated for dental erosion. The tested anti-erosive dentifrice was unable to protect enamel when erosion was associated to toothbrushing abrasion.


Assuntos
Compostos de Cálcio/química , Dentifrícios/química , Fosfatos/química , Silicatos/química , Fluoreto de Sódio/química , Erosão Dentária/prevenção & controle , Animais , Bovinos , Estudos Cross-Over , Esmalte Dentário , Humanos , Método Simples-Cego , Escovação Dentária
7.
Biochem Med (Zagreb) ; 29(1): 010901, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30591815

RESUMO

Introduction: In the last 20 years glycated albumin (GA) measurement has been demonstrated to be a reliable glycation marker and recently as the most innovative one in western countries. Glycated albumin has been already adopted by some Asian countries due to its usefulness in diabetes screening. The aim of the present study was to investigate for the first time the effects of different anticoagulants on GA assay. Materials and methods: From each of 60 patients a serum tube and K3EDTA, Li-Heparin and NaF-EDTA containing tubes were collected. All tubes were from Sarstedt (Verona, Italy). Glycated albumin was measured in duplicate in each sample tube in a single analytical run with quantILab glycated albumin (Instrumentation Laboratory SpA - A Werfen Company, Milan, Italy) on Architect c8000 analyser (Abbott SRL, Rome, Italy). Comparison of GA% in evaluated tubes was made by paired Wilcoxon test. Results: Median and interquartile range GA% concentrations were 15.4% (13.2 - 19.1) in serum, 15.7% (13.6 - 19.9) in K3EDTA, 15.6% (13.3 - 19.7) in Li-heparin and 15.5% (13.1 - 19.3) in NaF-EDTA samples, respectively. Glycated albumin mean relative bias respect to serum was within desirable bias derived from biological variation studies (± 2.9%) when K3EDTA (+ 2.8%), Li-heparin (+ 0.9%) or NaF-EDTA (+ 0.1%), were used as anticoagulants. Conclusions: Our results demonstrate that the GA% assay is not affected by relevant interferences when K3EDTA, Li-heparin or NaF-EDTA are used as anticoagulants, so they can be used interchangeably without a relevant impact on the clinical use of the test.


Assuntos
Anticoagulantes/química , Albumina Sérica/análise , Coleta de Amostras Sanguíneas , Ácido Edético/química , Heparina/química , Humanos , Lítio/química , Fluoreto de Sódio/química
8.
Oper Dent ; 44(1): 76-87, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29953340

RESUMO

OBJECTIVES:: To evaluate the effect of a remineralizing gel combining fluoride and calcium silicate/phosphate or a sodium fluoride gel on bleached enamel microhardness, color, and wear susceptibility. METHODS AND MATERIALS:: Two hundred forty bovine enamel-dentin samples were prepared. Baseline analysis of Knoop microhardness, color coordinates (L*a*b*), and surface profile were performed. According to the baseline microhardness values, specimens were stratified into six groups (n=40): NC (negative control)-no treatment; BL (positive control)-bleaching with 40% hydrogen peroxide gel (Opalescence Boost, Ultradent); BL/Rs-bleaching + application of calcium silicate/phosphate gel (Regenerate Serum, Unilever - Rs); Rs/BL-Rs + bleaching; Rs/BL/Rs-Rs + bleaching + Rs; and BL/F-bleaching + 2% sodium fluoride gel. After the treatment described for each group, color change (ΔE) and microhardness were evaluated again. To evaluate abrasion susceptibility, samples were randomly divided into two subgroups, according to the toothpaste used (Cp-Close Up or Rt-Regenerate), and underwent 100,000 brushing strokes. The profile of each sample was evaluated and the mean wear calculated. The data were analyzed by ANOVA and Tukey tests. RESULTS:: All bleached groups showed a significant reduction of microhardness in relation to the negative control. The groups treated with remineralizing gels showed a significantly higher microhardness and less wear than the positive control, although nonsignificant differences were observed among them. Nonsignificant differences in ΔE were found among bleached groups. The groups brushed with Regenerate toothpaste showed significantly less wear than those brushed with Close Up toothpaste. CONCLUSIONS:: The remineralizing gels did not interfere with bleaching efficacy. However, all the treatments minimized the surface hardness reduction caused by the bleaching procedure and enamel loss after abrasion. Regenerate toothpaste resulted in less enamel abrasion.


Assuntos
Esmalte Dentário/efeitos dos fármacos , Clareamento Dental/efeitos adversos , Remineralização Dentária/métodos , Desgaste dos Dentes/induzido quimicamente , Animais , Compostos de Cálcio/química , Bovinos , Cor , Dentifrícios/química , Géis/química , Dureza , Peróxido de Hidrogênio/química , Técnicas In Vitro , Teste de Materiais , Silicatos/química , Fluoreto de Sódio/química , Propriedades de Superfície
9.
Dent Mater ; 34(12): e344-e352, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30482611

RESUMO

OBJECTIVE: To evaluate the remineralising effect of the adjunctive application of 38% silver diamine fluoride (SDF) solution and 5% sodium fluoride (NaF) varnish on artificial enamel caries lesions. METHODS: Forty-eight demineralised enamel specimens were allocated into four groups. Group 1 received 38% SDF and 5% NaF; Group 2 received 38% SDF; Group 3 received 5% NaF; and Group 4 received deionized water. After pH cycling, the surface morphology and fluoride content of the specimens were studied via scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS). The lesion depth and crystal characteristics were assessed using micro-computed tomography and X-ray diffraction (XRD) respectively. The crystallization reaction was performed by incubating hydroxyapatite powder with NaF or SDF for 48h. The precipitates were studied via transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). RESULTS: SEM demonstrated the destruction of the enamel surface in Group 4. EDS revealed that the mean fluoride weight percentage of Groups 1-4 were 1.28±0.15, 1.33±0.19, 1.03±0.09 and 0.87±0.04 respectively. The mean lesion depths of Groups 1-4 were 129±14µm, 131±16µm, 153±10µm and 181±21µm respectively. The addition of NaF to SDF did not reduce the lesion depths (p=0.779). XRD revealed that silver chloride formed as a main product in Groups 1 and 2. Meanwhile, TEM analysis indicated that silver nanoparticles were incorporated into hydroxyapatite crystal in SDF-treated hydroxyapatite. XPS spectra suggested that the chemical state of the silver was metallic. SIGNIFICANCE: The adjunctive application of SDF and NaF varnish had a similar remineralising effect to that of SDF on enamel caries.


Assuntos
Esmalte Dentário/efeitos dos fármacos , Compostos de Amônio Quaternário/química , Compostos de Prata/química , Fluoreto de Sódio/química , Remineralização Dentária/métodos , Cristalização , Durapatita/química , Fluoretos Tópicos/química , Humanos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Espectroscopia Fotoeletrônica , Espectrometria por Raios X , Propriedades de Superfície , Difração de Raios X , Microtomografia por Raio-X
10.
BMC Med Imaging ; 18(1): 34, 2018 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-30236078

RESUMO

BACKGROUND: There are no objective and accurate rating tools for permanent impairment of traumatized ankles. The purpose of this study is to assess the role of 18F-Sodium fluoride (18F-NaF) positron emission tomography-computed tomography (PET/CT) bone scans in evaluating patients with limited ankle range of motion (ROM) after trauma. METHODS: 18F-NaF PET/CT was performed in 121 patients (75 men, 46 women; mean age: 45.8) who had ROM < 70% of normal after trauma affecting ankles. Metabolic target volume (MTV), the sum of voxels with standardized uptake value (SUV) > 2.5 was automatically obtained from the 3D volume that included the ankle joint. The maximum & mean SUV (SUVmax & SUVmean), and the total lesion activity (TLA) were measured. RESULTS: The median period from injury to performing 18F-NaF PET/CT was 290 days. The causes of injury were as follows: fracture (N = 95), Achilles tendon rupture (N = 12), and ligament injury (N = 12). Hot uptake in the ankle was seen in 113 of 121 patients. The fracture group had higher SUVmax, SUVmean, and TLA values than the non-fracture group. More limited ROM correlated with higher hot-uptake parameters (SUVmax, SUVmean, TLA). In subgroup analysis, the same correlations were present in the fracture, but not in the non-fracture group. CONCLUSIONS: 18F-NaF PET/CT can provide considerable information in impairment evaluations of limited ankle ROM, particularly in fracture around the ankle. Thus, 18F-NaF bone PET/CT may provide an additional option as an objective imaging tool in disability assessment after ankle injury.


Assuntos
Tendão do Calcâneo/lesões , Fraturas do Tornozelo/epidemiologia , Traumatismos do Tornozelo/diagnóstico por imagem , Ligamentos Laterais do Tornozelo/lesões , Ruptura/diagnóstico por imagem , Adolescente , Adulto , Idoso , Fraturas do Tornozelo/diagnóstico por imagem , Traumatismos do Tornozelo/fisiopatologia , Avaliação da Deficiência , Feminino , Radioisótopos de Flúor/química , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Amplitude de Movimento Articular , Reprodutibilidade dos Testes , Ruptura/epidemiologia , Fluoreto de Sódio/química , Distribuição Tecidual , Adulto Jovem
11.
Contrast Media Mol Imaging ; 2018: 8271313, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30254551

RESUMO

Our study aimed at comparing the diagnostic value of 18F-NaF positron emission tomography-computed tomography (PET/CT) and 18F-fluorodeoxyglucose (FDG) PET/CT for detection of skull-base invasion and osseous metastases in patients with nasopharyngeal carcinoma (NPC). Our study retrospectively analyzed 45 patients with pathologically proven NPC. They all underwent both 18F-NaF PET/CT and 18F-FDG PET/CT within a 7-day interval. Bone metastases were confirmed by follow-up using PET/CT, enhance-contrast computed tomography (CT), and magnetic resonance image (MRI). These two examinations were compared using per-patient-based analysis and per-lesion-based analysis. 18F-NaF PET/CT detected 27 patients with skull-base invasion, whereas 18F-FDG PET/CT detected 17 patients. 18F-NaF PET/CT and 18F-FDG PET/CT differed significantly in diagnosing skull-base invasion (p=0.02) and sensitivity (p=0.008). The sensitivity, specificity, and agreement rate of 18F-NaF PET/CT for detecting bone metastatic lesions were 98.3%, 65.7%, and 92.9%, respectively; these values were 42.9%, 97.1%, and 51.9%, respectively, for 18F-FDG PET/CT. 18F-NaF PET/CT and 18F-FDG PET/CT differed significantly in the number of osseous metastases detected (t=2.45, p=0.18) sensitivity (p < 0.0001) and specificity (p=0.003). In patients with nasopharyngeal carcinoma, 18F-NaF PET/CT assessed invasion of the skull base better and detected more osseous metastases than 18F-FDG PET/CT.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/secundário , Fluordesoxiglucose F18/química , Carcinoma Nasofaríngeo/patologia , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Base do Crânio/diagnóstico por imagem , Base do Crânio/patologia , Fluoreto de Sódio/química , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Adulto Jovem
12.
Chemosphere ; 207: 676-681, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29857199

RESUMO

Fluoride is a widespread environmental pollutant which can induce low sperm quality and fertilizing ability. However, effect of fluoride on proteomic changes of sperm is unknown. In this study, two-dimensional electrophoresis (2DE) and mass spectrometry (MS) were used to investigate the differently expressed proteins of sperm from mice exposed to fluoride. 180 male mice were randomly divided into three groups, and were administrated with the distilled water containing 0, 25, and 100 mg L-1 NaF, respectively. After 45, 90 and 180 day's exposure, mice were sacrificed and sperm from the cauda epididymis and vas deferens were collected for 2DE. 16 differently expressed spots were picked up to identify using MS, 15 of which were successfully identified. Many of them are associated with the sperm function such as sperm motility, maturation, capacitation and acrosome reaction, lipid peroxidation, detoxification, inflammation, and stability of membrane structure. These results could contribute to the explanation and further research of mechanisms underlying sperm damage induced by fluoride.


Assuntos
Proteômica/métodos , Fluoreto de Sódio/química , Espermatozoides/efeitos dos fármacos , Animais , Masculino , Camundongos
13.
J Photochem Photobiol B ; 185: 1-9, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29852327

RESUMO

Photosynthetic oxygen evolution occurs through the oxidation of water at a catalytic Mn4CaO5 cluster in photosystem II and is promoted by chloride, which binds at two sites near the Mn4CaO5 cluster. Fluoride is a competitive inhibitor of chloride activation, but study of its effects is complicated by the possibility that it may form an insoluble CaF2 complex. In this study, the effects of fluoride were studied using PSII lacking the PsbP and PsbQ subunits, which help to regulate the requirements for the inorganic cofactors Ca2+ and Cl-. In this preparation, which allows easy exchange of ions, it was found that F- does not directly remove Ca2+ even when catalytic turnovers take place, suggesting that fluoride is not able to access the inner coordination sphere of Ca2+. By monitoring the loss in O2 evolution activity, the dissociation constant of F- was estimated to be about 1 mM in intact PSII, consistent with previous studies, and about 77 mM in PSII lacking the extrinsic subunits. The significantly higher value for PSII lacking PsbP and PsbQ is consistent with results for other ions. The effects of F- on electron transfer to Tyr Z was also studied and found to show similar trends in PSII with and without the two extrinsic subunits, but with a more pronounced effect in PSII lacking the extrinsic subunits. These results indicate that in PSII lacking PsbP and PsbQ, fluoride does not directly interact with or remove Ca2+ and inhibits O2 evolution in a manner comparable to PSII with the extrinsic subunits intact.


Assuntos
Fluoretos/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Proteínas de Plantas/metabolismo , Cálcio/química , Espectroscopia de Ressonância de Spin Eletrônica , Fluoretos/química , Oxigênio/metabolismo , Complexo de Proteína do Fotossistema II/antagonistas & inibidores , Proteínas de Plantas/antagonistas & inibidores , Ligação Proteica , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Cloreto de Sódio/química , Cloreto de Sódio/metabolismo , Fluoreto de Sódio/química , Fluoreto de Sódio/metabolismo , Spinacia oleracea/metabolismo , Tirosina/química , Tirosina/metabolismo
14.
J Appl Oral Sci ; 26: e20170222, 2018 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-29768522

RESUMO

The effect of fluoride agents on the retention of orthodontic brackets to enamel under erosive challenge is little investigated. The aim of this study was to evaluate the effect of titanium tetrafluoride (TiF4) and sodium fluoride (NaF) agents on the shear bond strength of brackets to enamel and on the enamel microhardness around brackets under erosive challenge. Brackets were bonded to bovine incisors. Five groups were formed according to fluoride application (n=10): TiF4 varnish, TiF4 solution, NaF varnish, NaF solution and control (without application). The specimens were submitted to erosive challenge (90 s cola drink/2h artificial saliva, 4x per day for 7 days). Solutions were applied before each erosive cycle and varnishes were applied once. Vickers Microhardness (VHN) was obtained before and after all cycles of erosion and the percentage of microhardness loss was calculated. Shear bond strength, adhesive remnant index and polarized light microscopy were conducted after erosion. The data were analyzed by ANOVA, Tukey, Kruskal-Wallis and Mann-Whitney U tests (α=0.05). The %VHN had no statistically significant differences among the experimental groups. However, considering the comparisons of all groups with the control group, TiF4 varnish showed the highest protection from enamel demineralization (effect size of 2.94, while the effect size for the other groups was >2.4). The TiF4 varnish group had significantly higher shear bond strength compared to other groups. There was no difference among groups for adhesive remnant index. Polarized light microscopy showed higher demineralization depth for the control group. Application of NaF and TiF4 agents during mild erosive challenge minimized the enamel mineral loss around brackets, however only the experimental TiF4 varnish was able to prevent the reduction of shear bond strength of brackets to enamel.


Assuntos
Cariostáticos/química , Colagem Dentária/métodos , Esmalte Dentário/efeitos dos fármacos , Fluoretos/química , Braquetes Ortodônticos , Fluoreto de Sódio/química , Titânio/química , Erosão Dentária/prevenção & controle , Análise de Variância , Animais , Bovinos , Esmalte Dentário/química , Testes de Dureza , Teste de Materiais , Microscopia de Polarização , Valores de Referência , Reprodutibilidade dos Testes , Saliva Artificial/química , Resistência ao Cisalhamento , Estatísticas não Paramétricas , Propriedades de Superfície , Desmineralização do Dente/prevenção & controle
15.
Biochem Med (Zagreb) ; 28(2): 020701, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29666554

RESUMO

Introduction: Plasma lactate is a frequently used and important parameter for medical decision making. To setup a pre-analytical algorithm, we aimed to investigate the influence of different test tube additives, aliquoting, ice storage and haemolysis on plasma lactate concentrations for possible sparing critically ill (ICU) patients of additional blood drawing. Materials and methods: In our study (N = 177), lactate concentration and haemolysis index (HI) were measured in aliquoted (AHP) and unaliquoted (HP) Li-heparin, NaF/K3EDTA and NaF/KOX plasma, centrifuged within 15 minutes after venipuncture, on Cobas c501 analyzer. Differences were tested using the Wilcoxon's test and Passing-Bablok regression. Clinical accuracy of results was assessed in 107 ICU patients based on reference interval and clinical decision limits. Results: Lactate concentrations did not differ in NaF/K3EDTA and NaF/KOX plasma (P = 0.855). No clinically significant difference of AHP compared to NaF/K3EDTA lactate was found (y = 0.13 (0.08 to 0.19) + 1.02 (0.99 to 1.08) x) if samples were aliquoted within 30 minutes after venipuncture. On contrary, lactate concentrations in HP showed significant proportional difference (y = 0.07 (- 0.12 to 1.24) + 1.37 (1.22 to 1.56) x) and were clinically incorrect in 14% of patients. Transport in ice bath increases HI in NaF/K3EDTA (P < 0.001), but without influencing lactate results compared to room temperature (y = 0.03 (- 0.06 to 1.00) + 1.05 (0.99 to 1.11) x). Conclusions: Lactate determination in HP is unacceptable because of high proportional error and high risk of clinical inaccuracy compared to NaF/K3EDTA. If pre-analytical conditions are met, AHP, NaF/K3EDTA and NaF/KOX plasma can be used interchangeably. Aliquoted Li-heparin samples alow measurement of other biochemical tests from a single tube and can spare ICU patients from additional blood drawing. Storage in ice bath provides no additional stabilization in NaF/K3EDTA tubes.


Assuntos
Anticoagulantes/química , Ácido Edético/química , Heparina/química , Ácido Láctico/sangue , Lítio/química , Fluoreto de Sódio/química , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Automação Laboratorial , Estudos de Casos e Controles , Estado Terminal , Feminino , Hemólise , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
16.
Adv Clin Chem ; 84: 101-123, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29478513

RESUMO

The measurement of fasting plasma glucose may be biased by a time-dependent decrease of glucose in blood tubes, mainly attributable to blood cell metabolism when glycolysis is not rapidly inhibited or blood cells cannot be rapidly separated from plasma. Although glycolysis inhibitors such as sodium fluoride (NaF) in combination with potassium oxalate (KOx) are currently used for overcoming this drawback, their efficacy for stabilizing blood glucose is seemingly limited, and probably lower than that of newer additives such as the citrate buffer. Therefore, we performed a critical analysis of the current scientific literature aimed to generate evidence-based information about the advantages of using citrate buffer in blood tubes compared to the more conventional NaF additive. The results of our systematic overview of the literature show that citrate blood tubes represent a considerable step forward in achieving more accurate and reliable plasma glucose measurements, thereby limiting the risk of underdiagnosing diabetes due to spurious decrease of glucose concentration in uncentrifuged blood specimens, ensuring higher stability of glucose levels over time, while simultaneously producing less hemolysis compared to NaF blood tubes. Therefore, we suggest that the use of this new mixture should be encouraged for achieving a higher degree of accuracy and standardization of plasma glucose measurements.


Assuntos
Glicemia/análise , Coleta de Amostras Sanguíneas/métodos , Animais , Tampões (Química) , Citratos/química , Diabetes Mellitus/sangue , Diabetes Mellitus/diagnóstico , Glicólise/efeitos dos fármacos , Humanos , Fluoreto de Sódio/química
17.
J Contemp Dent Pract ; 19(2): 221-225, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29422474

RESUMO

INTRODUCTION: Force decay elastomeric chains are significant, and it is a clinical problem. AIM: The aim of this study was to evaluate the effects of bleaching agent in the mouthwash on the force decay of orthodontic chains. MATERIALS AND METHODS: In this experimental study, 160 gray closed elastomeric chains were randomly divided into three groups (one control and two test groups). Four loops of chains were stretched for 25 mm on custom-made jig. Control group specimens were immersed in artificial saliva during the test period. Test group specimens were immersed twice a day for 30 seconds in the whitening (LISTERINE® HEALTHY WHITE™) and daily sodium fluoride (LISTERINE® TOTAL CARE ZERO) mouthwashes. All specimens were immersed in artificial saliva at 37°C. Force was measured at different time points (initial, 1, 7, 14, 21, 28 days). Statistical analysis was performed by two-way analysis of variance (ANOVA) and Bonferroni methods (a = 0.05). RESULTS: Force of elastomeric chains was decreased dramatically in all groups during the experiment. After 24 hours, force was decreased by 42.18, 48.34, and 53.38% in control group, daily, and bleaching mouthwash groups respectively. The corresponding numbers after 4 weeks were 66.30, 76.73, and 86.48. The difference between three groups at days 1 and 28 was statistically significant (p < 0.05). CONCLUSION: Within the limitations of the current in vitro study, bleaching and sodium fluoride mouthwashes could cause force decay of orthodontic elastomeric chains. Whitening mouthwash is more weakening for elastomeric chains. CLINICAL SIGNIFICANCE: Use of whitening mouthwash by orthodontic patients could decrease the force of elastomeric chains, so it could be recommended to use them for a short time.


Assuntos
Elastômeros/química , Antissépticos Bucais/química , Aparelhos Ortodônticos , Clareadores Dentários/química , Elasticidade , Teste de Materiais , Saliva Artificial , Fluoreto de Sódio/química , Resistência à Tração
18.
Tissue Eng Part A ; 24(15-16): 1207-1217, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29376480

RESUMO

In a previous study, we successfully prepared fluorinated porcine hydroxyapatite (FPHA) by immersing porcine hydroxyapatite (PHA) in an aqueous solution of 0.25 M sodium fluoride (NaF) under thermal treatment, and the resulting FPHA showed better physicochemical and biological properties than PHA. The purpose of this study was to further investigate how fluorine incorporation influenced the biocompatibility and osteogenic capacity of PHA. The concentrations of Ca, P, F, and Mg ions in PHA and FPHA extracts were detected by inductively coupled plasma optical emission spectrometry. Rat bone marrow stromal cells (rBMSCs) were treated with PHA and FPHA extracts, and the effects of these extracts on cell proliferation and osteoblastic differentiation were evaluated via Cell Counting Kit-8 assay, alkaline phosphatase assay, and real time-quantitative polymerase chain reaction. For the in vivo assessment, PHA and FPHA were implanted into subcutaneous pockets (n = 6) and rat calvarial defects (diameter = 5 mm, n = 14) for 12 weeks to determine their biocompatibility and osteogenic capacity by using micro-computed tomography (CT) and histological analysis. FPHA extracts, which release higher concentrations of F and Mg ions, better promoted the osteoblastic differentiation of rBMSCs in vitro. The result of biocompatibility evaluation confirmed that the host response and chronic inflammation cells infiltration degree around PHA and FPHA granules were similar. Micro-CT and histological analysis showed newer mineralized bone formation in rats with FPHA-treated defects than in rats with PHA-treated defects. The results of in vitro and in vivo tests consistently indicate that fluorine incorporation effectively enhanced the osteogenic capacity of PHA.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Durapatita , Células-Tronco Mesenquimais/metabolismo , Osteogênese/efeitos dos fármacos , Fluoreto de Sódio/química , Animais , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Durapatita/química , Durapatita/farmacologia , Masculino , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , Osteoblastos/metabolismo , Ratos , Ratos Sprague-Dawley , Suínos
19.
Talanta ; 178: 491-497, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29136853

RESUMO

A new simple and highly sensitive electrochemical method for pyrophosphatase (PPase) activity detection was developed based on the peroxidase-like activity of G-quadruplex-Cu2+ DNAzyme. In the absence of PPase, Cu2+ could coordinate with pyrophosphate (PPi) to form Cu2+-PPi compound. While in the presence of PPase, it could destroy the coordinate compound because PPase catalyzed the hydrolysis of PPi into inorganic phosphate and produced free Cu2+, which then could be coupled with G-rich DNA to form G-quadruplex-Cu2+ DNAzyme. The formation of a mimic enzyme (G-quadruplex-Cu2+ DNAzyme) was immobilized on the surface of screen-printed gold electrode (SPGE). Using 3, 3', 5, 5'-tetramethylbenzidine (TMB) as a redox mediator and H2O2 as an enzyme substrate, the DNAzyme catalyzed the reduction of H2O2 to generate quantitative chronoamperometric signal. The catalytic activity of G-quadruplex-Cu2+ DNAzyme for TMB-H2O2 reaction was proportional to the activity of PPase, based on which, a simple and sensitive turn-on electrochemical method for PPase activity was thus developed for the first time. The chronoamperometric intensity of the system had a linear relationship with the PPase activities in the range of 1.0-50.0mU/mL and the detection limit could be down to 0.6mU/mL (S/N = 3). This proposed method was selective, cost-effective and convenient without any labels or complicated operations, which was furthermore applied to screen the inhibitor for PPase with high efficiency.


Assuntos
Cobre/química , DNA Catalítico/química , Técnicas Eletroquímicas/métodos , Enzimas Imobilizadas/química , Quadruplex G , Pirofosfatases/análise , Eletrodos , Ouro/química , Peroxidases , Pirofosfatases/antagonistas & inibidores , Pirofosfatases/química , Fluoreto de Sódio/química
20.
J Prosthodont Res ; 62(1): 104-109, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28916465

RESUMO

PURPOSE: This study aimed to investigate the effect of sodium fluoride (NaF) on titanium corrosion using a biofilm model, taking environmental pH into account. METHODS: Streptococcus mutans cells were used as the artificial biofilm, and pH at the bacteria-titanium interface was monitored after the addition of 1% glucose with NaF (0, 225 or 900ppmF) at 37°C for 90min. In an immersion test, the titanium samples were immersed in the NaF solution (0, 225 or 900ppm F; pH 4.2 or 6.5) for 30 or 90min. Before and after pH monitoring or immersion test, the electrochemical properties of the titanium surface were measured using a potentiostat. The amount of titanium eluted into the biofilm or the immersion solution was measured using inductively coupled plasma mass spectrometry. The color difference (ΔE*ab) and gloss of the titanium surface were determined using a spectrophotometer. RESULTS: After incubation with biofilm, pH was maintained at around 6.5 in the presence of NaF. There was no significant change in titanium surface and elution, regardless of the concentration of NaF. After immersion in 900ppm NaF solution at pH 4.2, corrosive electrochemical change was induced on the surface, titanium elution and ΔE*ab were increased, and gloss was decreased. CONCLUSIONS: NaF induces titanium corrosion in acidic environment in vitro, while NaF does not induce titanium corrosion under the biofilm because fluoride inhibits bacterial acid production. Neutral pH fluoridated agents may still be used to protect the remaining teeth, even when titanium-based prostheses are worn.


Assuntos
Biofilmes , Materiais Dentários/química , Fluoreto de Sódio/química , Streptococcus mutans/fisiologia , Titânio/química , Corrosão , Eletroquímica , Concentração de Íons de Hidrogênio , Fluoreto de Sódio/farmacologia , Soluções , Streptococcus mutans/efeitos dos fármacos , Temperatura , Fatores de Tempo
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