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1.
Oral Health Prev Dent ; 18(4): 713-718, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32895654

RESUMO

PURPOSE: To investigate dentin abrasivity and cleaning efficacy of novel/alternative toothpastes containing diamond particles, active carbon, sea salt or organic oils. MATERIALS AND METHODS: Seventy-two bovine dentin samples (for measuring abrasivity) and 60 human dentin samples (for assessing cleaning efficacy) were used in this study. Samples were divided into six groups as follows: group 1: Elmex Kariesschutz (hydrated silica); group 2: Lavera Neutral Zahngel (sea salt); group 3: Curaprox Black is White (active carbon); group 4: Swiss Smile Diamond Glow (diamond powder); group 5: Ringana Fresh Tooth Oil (hydrated silica); and group 6: artificial saliva. Samples were brushed for a total of 26 min at 120 strokes/min, replacing slurries (1 part respective toothpaste and 2 parts artificial saliva) every 2 min. Finally, abrasive dentin wear was measured profilometrically and cleaning efficacy planimetrically. RESULTS: The highest abrasivity values were observed for Lavera Neutral Zahngel (sea salt 9.2 µm) and Elmex Kariesschutz group (hydrated silica 6.0 µm). The lowest abrasivity value was observed for Ringana Fresh Tooth Oil group (hydrated silica 1.3 µm). The highest cleaning efficacy was observed for Elmex Kariesschutz group (86.7%) and the lowest cleaning efficacy was observed for Ringana Fresh Tooth Oil group (31.3%). CONCLUSION: The addition of diamond powder or active carbon to toothpastes could offer high cleaning efficacy with low dentin abrasivity. The addition of sea salt to traditional abrasives might cause high abrasive dentin wear without adding further cleaning benefit.


Assuntos
Abrasão Dentária , Cremes Dentais , Animais , Bovinos , Dentina , Humanos , Saliva Artificial , Escovação Dentária
2.
Emerg Microbes Infect ; 9(1): 1415-1417, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: covidwho-526750

RESUMO

SARS-CoV-2, the causative agent of the COVID-19 pandemic, may be transmitted via airborne droplets or contact with surfaces onto which droplets have deposited. In this study, the ability of SARS-CoV-2 to survive in the dark, at two different relative humidity values and within artificial saliva, a clinically relevant matrix, was investigated. SARS-CoV-2 was found to be stable, in the dark, in a dynamic small particle aerosol under the four experimental conditions we tested and viable virus could still be detected after 90 minutes. The decay rate and half-life was determined and decay rates ranged from 0.4 to 2.27 % per minute and the half lives ranged from 30 to 177 minutes for the different conditions. This information can be used for advice and modelling and potential mitigation strategies.


Assuntos
Aerossóis/química , Betacoronavirus/crescimento & desenvolvimento , Infecções por Coronavirus/virologia , Meios de Cultura/química , Pneumonia Viral/virologia , Saliva Artificial/química , Salvia/virologia , Microbiologia do Ar , Betacoronavirus/química , Betacoronavirus/genética , Betacoronavirus/efeitos da radiação , Infecções por Coronavirus/transmissão , Escuridão , Humanos , Umidade , Cinética , Pandemias , Pneumonia Viral/transmissão
3.
Emerg Microbes Infect ; 9(1): 1415-1417, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32496967

RESUMO

SARS-CoV-2, the causative agent of the COVID-19 pandemic, may be transmitted via airborne droplets or contact with surfaces onto which droplets have deposited. In this study, the ability of SARS-CoV-2 to survive in the dark, at two different relative humidity values and within artificial saliva, a clinically relevant matrix, was investigated. SARS-CoV-2 was found to be stable, in the dark, in a dynamic small particle aerosol under the four experimental conditions we tested and viable virus could still be detected after 90 minutes. The decay rate and half-life was determined and decay rates ranged from 0.4 to 2.27 % per minute and the half lives ranged from 30 to 177 minutes for the different conditions. This information can be used for advice and modelling and potential mitigation strategies.


Assuntos
Aerossóis/química , Betacoronavirus/crescimento & desenvolvimento , Infecções por Coronavirus/virologia , Meios de Cultura/química , Pneumonia Viral/virologia , Saliva Artificial/química , Salvia/virologia , Microbiologia do Ar , Betacoronavirus/química , Betacoronavirus/genética , Betacoronavirus/efeitos da radiação , Infecções por Coronavirus/transmissão , Escuridão , Humanos , Umidade , Cinética , Pandemias , Pneumonia Viral/transmissão
4.
Dent Mater ; 36(3): 456-467, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32008748

RESUMO

OBJECTIVE: The aim is to investigate the potential significance of combining minimally invasive high-intensity focused ultrasound (HIFU) with hydroxyapatite (HA) nanorods treatment for the remineralization of demineralized coronal dentine-matrix. METHODS: HA having nanorods structure were synthetized using ultrasonication with precipitation method. HA nanorods were characterized by TEM for average-size/shape. Following phosphoric acid demineralization, dentine specimens were treated with HA-nanorods with/without subsequent HIFU exposure for 5 s, 10 s and 20 s then stored in artificial saliva for 1-month. Dentine specimens were characterized using different SEM and Raman spectroscopic techniques. In addition, the biochemical stability and HA-nanorods were examined using ATR-FTIR to observe attachment of nanoparticles. Also, surface nanoindentation properties were evaluated using AFM in tapping-mode. RESULTS: HA-nanorods displayed well-defined, homogenous plate-like nanostructure. TEM revealed intact collagen-fibrils network structure with high density due to obliteration of interfibrillar spaces with clear evidence of remineralization in combined HA/HIFU treatment. With HA-nanorods treatment collagen-network structure was visible, consisting of fibrils interlaced into a compact pattern with evidence of minerals deposition. AFM investigation revealed clear mineral formation with the increase of HIFU exposure time. Bands associated with inorganic phase dominate well in HIFU exposed specimens with PO stretching within dentine mineral identified at 960 cm-1. Characteristic dentine structure for control and HIFU 20 s specimens is reflected as oscillatory mean Amide-I intensity with measurement giving a precise sinusoidal response of polarization angle ß within dentinal tissue. Nanoindentation testing showed a gradual significant increase in elastic-modulus with the increase in HIFU exposure time after 1-month storage. FTIR spectrum of the HIFU exposed dentine displayed bands at 1650 cm-1, 1580 cm-1 and 1510 cm-1 that can be attributed to Amide-I, II and III. SIGNIFICANCE: The synergetic effect of HIFU exposure on remineralization potential of demineralized dentine-matrix following nano-hydroxyapatite treatment was revealed. This synergetic effect is dependent on HIFU exposure time.


Assuntos
Durapatita , Nanotubos , Dentina , Saliva Artificial , Remineralização Dentária
5.
Oper Dent ; 45(3): E114-E123, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32053454

RESUMO

OBJECTIVE: The objective of this study was to evaluate the effect of erosion or erosion-abrasion on bioactive materials and adjacent enamel/dentin areas. METHODS AND MATERIALS: Enamel and dentin blocks (4×4×2 mm) were embedded side by side in acrylic resin, and a standardized cavity (1.2×4×1.5 mm) was prepared between them. Preparations were restored with the following materials: composite resin (Filtek Z350, control); experimental composite containing di-calcium phosphate dihydrate particles (DCPD); Giomer (Beautifil II), high viscosity glass ionomer cement (GIC, Fuji IX); and a resin-modified GIC (Fuji II LC). The specimens were submitted to two cycling models (n=10): erosion or erosion-abrasion. The challenges consisted of five-minute immersion in 0.3% citric acid solution, followed by 60-minute exposure to artificial saliva. Toothbrushing was carried out twice daily, 30 minutes after the first and last exposures to acid. Dental and material surface loss (SL, in µm) were determined by optical profilometry. Data were analyzed with Kruskal-Wallis and Dunn tests (α=0.05). RESULTS: Under erosion, for enamel, only the GIC groups presented lower SL values than Z350 (p<0.001 for Fuji IX and p=0.018 for Fuji II LC). For dentin, none of the materials showed significantly lower SL values than Z350 (p>0.05). For material, the GICs had significantly higher SL values than those of Z350 (p<0.001 for Fuji IX and p=0.002 for Fuji II LC). Under erosion-abrasion, the enamel SL value was significantly lower around Fuji II LC compared with the other materials (p<0.05). No significant differences were observed among groups for dentin SL (p=0.063). The GICs and Giomer showed higher SL values than Z350 (p<0.001 for the GICs and p=0.041 for Giomer). CONCLUSION: Both GIC-based materials were susceptible to erosive wear; however, they promoted the lowest erosive loss of adjacent enamel. Against erosion-abrasion, only Fuji II LC was able to reduce enamel loss. For dentin, none of the materials exhibited a significant protective effect.


Assuntos
Esmalte Dentário , Cimentos de Ionômeros de Vidro , Materiais Dentários , Dentina , Saliva Artificial , Escovação Dentária
6.
Dent Mater ; 36(3): 431-441, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31992484

RESUMO

OBJECTIVE: The Ti-6Al-4V (TAV) alloy is commercially used as a dental implant material. This work seeks to elucidates the origins of degradation of Ti-6Al-4V (TAV) implant alloys that result in peri-implant bone loss. 
Methods: In this work, a combination of microstructure, surface, and solution analyses was utilized to study the corrosion mechanism of the TAV alloy in oral environments. The corrosion of TAV alloys in the F--enriched environment of a crevice was evaluated through nanoscale surface analysis. And, the findings were further rationalized via electrochemical means. 
 RESULTS: Our results suggest the bone loss was caused by crevice corrosion and the consequential release of by-products, and the crevice corrosion was potentially induced by the buildup of corrosive species such as fluorides, which are common additives in dental products. In turn, the corrosion properties of the TAV alloy were evaluated in fluoride enriched environments. Nanoscale analysis of corroded surfaces, carried out using vertical scanning interferometry (VSI) showed that the corrosion susceptibility of the constituent phases dictates the corrosion product species. In specific, the aluminum-rich α phase preferentially dissolves under potential-free conditions and promotes the formation of insoluble Al-Ti oxides. Notably, under conditions of applied potential, oxidative dissolution of the vanadium-rich ß phase is favored, and the vanadium release is promoted. 
 SIGNIFICANCE: These findings elucidate the origins of degradation of TAV-implants that result in the release of corrosion by-products into the local biological environment. More important, they offer guidelines for materials design and improvement to prevent this nature of degradation of dental implants.


Assuntos
Implantes Dentários , Ligas , Corrosão , Ligas Dentárias , Teste de Materiais , Saliva Artificial , Propriedades de Superfície , Titânio
7.
Talanta ; 209: 120501, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892087

RESUMO

In the present study, we have developed a capacitance electrochemical biosensor based on silicon nitride substrate (Si3N4/SiO2/Si[P]/Al) for Tumour Necrosis Factor Alpha (TNF-α) cytokines detection. Micro-contact printing, Fluorescence microscopy characterization and contact angle measurement (CAM) were carried out during the bio-functionalization of the biosensor surface. Mott-Schottky analyses were applied for TNF-α detection within the range of 1 pg/mL to 30 pg/mL in which the immunosensor has exhibited a good linearity, a sensitivity of 4 mV.pM-1 and 4.4 mV.pM-1 in PBS and artificial saliva (AS) respectively. While the LOD was found at 0.38 pg/mL and 1 pg/mL in PBS and AS respectively. The developed immunosensor has also demonstrated a high and good selectivity for TNF-α detection in human AS when compared to other interferences like Cortisol and Interleukin-10. The performances of the developed biosensor are very promising for biomedical application to predict the first sign of inflammation.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Saliva Artificial/química , Compostos de Silício/química , Transdutores , Fator de Necrose Tumoral alfa/análise , Anticorpos Imobilizados/imunologia , Anticorpos Monoclonais/imunologia , Capacitância Elétrica , Técnicas Eletroquímicas/instrumentação , Eletrodos , Corantes Fluorescentes/química , Humanos , Imunoensaio/métodos , Limite de Detecção , Rodaminas/química , Dióxido de Silício/química , Fator de Necrose Tumoral alfa/imunologia
8.
Dent Mater J ; 39(3): 429-434, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31969546

RESUMO

This study aimed to evaluate the effects of artificial saliva contamination on a glass ionomer cement (GIC), a resin-modified GIC (RMGIC), and a composite resin (CR) that was used with two different etching adhesive systems. Three surface conditions were created on bovine teeth using artificial saliva: control (group I), mild saliva contamination (group II), and severe saliva contamination (group III). The microtensile bond strength (µTBS) of CR with dentin was significantly lower in group III than in group I. However, the µTBS of GIC and RMGIC with both enamel and dentin showed no significant intergroup differences. Moreover, CR exhibited significantly greater microleakage on cementum in group III than in group I, whereas both GIC and RMGIC showed no significant differences for both enamel and cementum. Thus, GIC and RMGIC may be suitable for preventing secondary caries after class V restorative treatments when contamination by saliva cannot be avoided.


Assuntos
Colagem Dentária , Infiltração Dentária , Animais , Bovinos , Resinas Compostas , Restauração Dentária Permanente , Dentina , Cimentos de Ionômeros de Vidro , Teste de Materiais , Cimentos de Resina , Saliva Artificial
9.
Oper Dent ; 45(2): 173-182, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31373890

RESUMO

This study compared the viscoelastic properties of restorative and flowable bulk-fill resin-based composites (RBCs) with their conventional counterparts and evaluated the impact of aqueous solutions on viscoelastic properties. The materials examined included three conventional RBCs (Filtek Z350, Tetric N Ceram, and Beautifil II), three restorative bulk-fill RBCs (Filtek Bulk-Fill Restorative, Tetric N Ceram Bulk-Fill, and Beautifil Bulk-Fill Restorative) in addition to three flowable bulk-fill RBCs (Filtek Bulk-Fill Flowable, Tetric N Flow Bulk-Fill, and Beautifil Bulk-Fill Flowable). Beam-shaped specimens (12×2×2 mm) were fabricated using customized stainless-steel molds, finished, and measured. The specimens were randomly divided into four groups and conditioned in air (control), artificial saliva, 0.02 N citric acid, and 50% ethanol-water solution for seven days at 37°C. They were then subjected to dynamic mechanical analysis (n = 10) in flexure mode at 37°C with a frequency of 0.1 to 10 Hz. Storage modulus, loss modulus, and loss tangent data were subjected to statistical analysis using one-way analysis of variance/Tukey post hoc test at a significance level of α = 0.05. Viscoelastic properties of the RBCs were found to be product and conditioning medium dependent. For most RBCs, exposure to aqueous solutions, particularly an ethanol-water solution, degraded viscoelastic properties. With the exception of Filtek Bulk-Fill Restorative, bulk-fill restorative and flowable RBCs generally had significantly lower storage and loss modulus than their conventional counterparts regardless of conditioning medium. Conventional RBCs are thus favored over their bulk-fill counterparts, particularly for high-stress-bearing areas.


Assuntos
Resinas Compostas , Materiais Dentários , Teste de Materiais , Saliva Artificial
10.
Ann Rheum Dis ; 79(1): 3-18, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31672775

RESUMO

The therapeutic management of Sjögren syndrome (SjS) has not changed substantially in recent decades: treatment decisions remain challenging in clinical practice, without a specific therapeutic target beyond the relief of symptoms as the most important goal. In view of this scenario, the European League Against Rheumatism (EULAR) promoted and supported an international collaborative study (EULAR SS Task Force) aimed at developing the first EULAR evidence and consensus-based recommendations for the management of patients with SjS with topical and systemic medications. The aim was to develop a rational therapeutic approach to SjS patients useful for healthcare professionals, physicians undergoing specialist training, medical students, the pharmaceutical industry and drug regulatory organisations following the 2014 EULAR standardised operating procedures. The Task Force (TF) included specialists in rheumatology, internal medicine, oral health, ophthalmology, gynaecology, dermatology and epidemiology, statisticians, general practitioners, nurses and patient representatives from 30 countries of the 5 continents. Evidence was collected from studies including primary SjS patients fulfilling the 2002/2016 criteria; when no evidence was available, evidence from studies including associated SjS or patients fulfilling previous sets of criteria was considered and extrapolated. The TF endorsed the presentation of general principles for the management of patients with SjS as three overarching, general consensus-based recommendations and 12 specific recommendations that form a logical sequence, starting with the management of the central triplet of symptoms (dryness, fatigue and pain) followed by the management of systemic disease. The recommendations address the use of topical oral (saliva substitutes) and ocular (artificial tear drops, topical non-steroidal anti-inflammatory drugs, topical corticosteroids, topical CyA, serum tear drops) therapies, oral muscarinic agonists (pilocarpine, cevimeline), hydroxychloroquine, oral glucocorticoids, synthetic immunosuppressive agents (cyclophosphamide, azathioprine, methotrexate, leflunomide and mycophenolate), and biological therapies (rituximab, abatacept and belimumab). For each recommendation, levels of evidence (mostly modest) and TF agreement (mostly very high) are provided. The 2019 EULAR recommendations are based on the evidence collected in the last 16 years in the management of primary 2002 SjS patients and on discussions between a large and broadly international TF. The recommendations synthesise current thinking on SjS treatment in a set of overarching principles and recommendations. We hope that the current recommendations will be broadly applied in clinical practice and/or serve as a template for national societies to develop local recommendations.


Assuntos
Antirreumáticos/uso terapêutico , Glucocorticoides/uso terapêutico , Imunossupressores/uso terapêutico , Lubrificantes Oftálmicos/uso terapêutico , Agonistas Muscarínicos/uso terapêutico , Saliva Artificial/uso terapêutico , Síndrome de Sjogren/tratamento farmacológico , Administração Oftálmica , Corticosteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/administração & dosagem , Ciclosporina/administração & dosagem , Humanos , Hidroxicloroquina/uso terapêutico
11.
Talanta ; 208: 120353, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816720

RESUMO

A porous and hydrophilic sorbent material was used in an extraction system, assisted by electric fields, for the extraction of cocaine in saliva and subsequent determination by ultra-high-performance liquid chromatography associated with sequential triple quadrupole mass spectrometry (UHPLC-MS/MS). The cellulose-based material was characterized by scanning electron microscopy, infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. The time and voltage variables applied in the extraction process were investigated through a Doehlert experimental design, and with the best conditions found (35min and 300 V) some validation parameters were evaluated. The established working range was 1-100 µg L-1 (R2 > 0.99), and the detection and quantification limits determined were 0.3 and 0.8 µg L-1, respectively. Recoveries from 80 to 115% and coefficient of variation ≤15 and 16% for intra-day and inter-day assays, respectively, were obtained for sample concentrations of LOQ, 5, 25, and 75 µg L-1, indicating satisfactory accuracy and precision for the proposed method. In addition, the method presented no matrix effect, and the extraction efficiency was between 56 and 70%. The results showed that the material used has adequate physicochemical characteristics and can be applied as a sorbent and electrolyte support in multiphase extractions using electric fields.


Assuntos
Celulose/química , Cromatografia Líquida de Alta Pressão/métodos , Cocaína/análise , Cocaína/isolamento & purificação , Saliva/metabolismo , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Fenômenos Eletromagnéticos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Saliva/química , Saliva Artificial/química , Saliva Artificial/metabolismo , Extração em Fase Sólida/instrumentação
12.
Dent Mater ; 35(12): 1757-1768, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31699444

RESUMO

The aim of this study was to characterize the ion release, pH changes and apatite formation ability of two potentially bioactive composites Cention N (CN) and Activa (ACT). Ion release and apatite formation was investigated in three different immersion media: Tris buffer pH 7.3 (TB), Artificial Saliva pH 4 (AS4) and Artificial Saliva pH 7 (AS7) in order to mimic the conditions present in the mouth. Fluoride release was followed using an ion selective electrode, whilst all other ions were determined by inductively coupled plasma optical emission spectroscopy. Apatite formation was followed by FTIR and XRD. SEM was used to follow glass degradation and apatite formation on both polished cross-sections and surfaces of the composites. ACT released very few ions including fluoride upon immersion in TB and AS7, but released more ions including significant quantities of Al in AS4. This would suggest the glasses in ACT are acid degradable fluoro-alumino-silicate glasses similar to the glasses used in glass ionomer cements. There was no evidence of any apatite formation with ACT. CN released more ions in TB and AS7 than ACT and formed an apatite like phase in AS7. The calcium fluoro-silicate glass in CN was observed to degrade significantly in AS4. CN has bioactive properties that may explain the low incidence of secondary caries found clinically with this composite.


Assuntos
Apatitas , Fluoretos , Cimentos de Ionômeros de Vidro , Teste de Materiais , Saliva Artificial , Silicatos , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Braz Oral Res ; 33: e101, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31778472

RESUMO

The aim of this study was to evaluate the influence of different calcium phosphates (CaPs) on the physical, biological, and remineralizing properties of experimental resin-based sealants (RBSs). Triethylene-glycol dimethacrylate (90wt%) and bisphenol A-glycidyl methacrylate (10wt%) were used to produce resin-based sealants. Hydroxyapatite (SHAp), α-tricalcium phosphate (Sα-TCP) and octacalcium phosphate (SOCP) were added to the sealants in a 10wt% concentration. One group without CaPs was used as the control group (SCG). The degree of conversion (DC) was assessed with Fourier-transformed infrared spectroscopy, whereas cytotoxicity was tested with the HaCaT keratinocyte cell line. The ultimate tensile strength (UTS) was used to assess the mechanical strength of the experimental RBSs. Sealed enamel was used for colorimetric assay. Mineral deposition was assessed with Raman spectroscopy after 7, 14, and 28 days of sample immersion in artificial saliva. Scanning electron microscopy was used to analyze the surface morphology after 28 days of immersion. The addition of 10wt% of fillers significantly reduced the DC of sealants. SOCP groups showed reduced cell viability. Higher UTS was found for Sα-TCP and SHAp. The color analysis showed that SGC and demineralized teeth presented higher mismatches with the sound tissue. Mineral deposition was observed for SHAp and Sα-TCP after 7 days, with increased phosphate content and mineral deposits for SHAp after 28 days. RBS with the addition of 10% HAp promoted increased mineralization in vitro after 28 days, and did not affect cell viability, DC, mechanical properties, or RBS color in the enamel.


Assuntos
Fosfatos de Cálcio/química , Durapatita/química , Minerais/química , Selantes de Fossas e Fissuras/química , Resinas Sintéticas/química , Animais , Fosfatos de Cálcio/toxicidade , Bovinos , Linhagem Celular , Colorimetria , Esmalte Dentário/química , Esmalte Dentário/efeitos dos fármacos , Durapatita/toxicidade , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Selantes de Fossas e Fissuras/toxicidade , Valores de Referência , Reprodutibilidade dos Testes , Resinas Sintéticas/toxicidade , Saliva Artificial/química , Análise Espectral Raman , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo
14.
J Indian Soc Pedod Prev Dent ; 37(3): 265-270, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31584026

RESUMO

Purpose: The study aimed to evaluate and compare the compressive strength and surface microhardness of EQUIA Forte, light cure, and conventional glass-ionomer cement (GIC). Methodology: Fifty-four pellets of G-Coat (GC) Gold Label 2, GC Gold Label light-cured universal restorative material, and EQUIA Forte GIC were prepared of dimensions (6 × 4) mm and were divided into three groups (18) each and were stored at 37°C for 1 h and then immersed in 20 ml of deionized water, artificial saliva, and lactic acid six each, respectively, over 30 days. Samples were subjected to surface microhardness and compressive strength test on the 1st day, 7th day, and 30th day. Results were subjected to ANOVA and Bonferroni post hoc test. Results: Comparing the compressive strength of EQUIA Forte from day 1 to 30 when placed in artificial saliva, there was a significant increase on day 30 (P = 0.007); compared to other groups. The surface microhardness of EQUIA Forte from day 1 to 30 when placed in artificial saliva nonsignificantly decreased comparing to other groups. Conclusion: Surface microhardness and compressive strength of EQUIA Forte were significantly high in comparison to the other groups.


Assuntos
Materiais Dentários , Cimentos de Ionômeros de Vidro , Força Compressiva , Teste de Materiais , Saliva Artificial
15.
Int J Pharm ; 571: 118759, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31622744

RESUMO

The sensation of dry mouth also referred to as xerostomia is becoming increasingly common worldwide. Current treatment strategies include topical agents, sialagogues and saliva substitutes. The latter have been reported to be ineffective as special physicochemical features of natural saliva have so far been ignored (e.g., buffer capacity, osmolality, etc.). The aim of this study was to comprehensively investigate the most relevant physicochemical properties of three products frequently used in the clinics and compare them to unstimulated whole saliva (UWS). Sialin-Sigma®, Glandomed® and Xylitol CVS HealthTM Dry Mouth Spray were characterized regarding their pH, osmolality, electrical conductivity, buffer capacity, rheological behaviour, microstructure, surface tension and wettability and compared to UWS. The influence of residual saliva was examined under consideration of the conditions of xerostomia to assess whether the quantity given in the instruction for use is appropriate. All three products showed significant differences to UWS regarding the values received. Only Xylitol CVS HealthTM Dry Mouth Spray showed a comparable wettability. It could be further determined that the recommended doses were too low. These data can not only be used for an improved understanding of saliva, but also for the development of a replacement fluid to successfully alleviate xerostomia.


Assuntos
Saliva Artificial/química , Saliva/química , Xerostomia/terapia , Administração Oral , Adulto , Aerossóis , Tampões (Química) , Linhagem Celular , Relação Dose-Resposta a Droga , Rotulagem de Medicamentos , Células Epiteliais , Feminino , Voluntários Saudáveis , Humanos , Masculino , Mucosa Bucal/citologia , Saliva Artificial/administração & dosagem , Xilitol/administração & dosagem , Xilitol/química
16.
Dent Mater ; 35(11): 1630-1636, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31543377

RESUMO

OBJECTIVE: To evaluate the protease activity in dentin matrices subjected to lactic acid (LA) in comparison to polyacrylic acid (PAA) challenge model at cathepsin K (CT-K) optimum pH 5.5 to assess effectiveness of inhibitors in dentin collagen degradation. METHODS: Dentin disks measuring 0.5mm prepared from human molars were completely demineralized in 10% H3PO4. Demineralized dentin disks were challenged with 0.1M LA, 1.1mM PAA, artificial saliva (AS), or deionized water (C) for 24h or 7-days. Dentin collagen properties were tested by measurement of %dry mass change, and ultimate tensile strength (UTS). Degradation of dentin type I collagen was measured by telopeptide assays measuring the sub-product release of C-terminal cross-linked telopeptides (ICTP) and C-terminal peptide (CTX) in the incubation media in relation to total protein concentration, which correlates with matrix metalloproteinases (MMPs) and CT-K activities. RESULTS: Gravimetric analysis showed statistically significant difference between C and other groups (p<0.04) at 24h. LA specimens showed significantly higher weight loss from 24h to 7-days (p=0.02). UTS revealed statistically significant difference between AS and LA at 24h and 7-days. UTS at 24h and 7-days for C and AS had significantly higher mean values compared to LA and PAA. Telopeptide assays reported that CTXtp results showed that LA at 24h had significantly higher mean values compared to C and AS. SIGNIFICANCE: LA has the ability to activate endogenous CT-K in dentin as measured by the release of CTX (CT-K specific telopeptide). This LA based model has the potential application for further investigations on the activity and possible inhibitors of CT-K in human dentin.


Assuntos
Dentina , Metaloproteinases da Matriz , Catepsina K , Colágeno Tipo I , Humanos , Saliva Artificial
17.
Colloids Surf B Biointerfaces ; 184: 110492, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31522026

RESUMO

The electrochemical properties of CoCrMo alloy immersed in different artificial saliva with or without Ca2+ and albumin were studied by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP), and meanwhile the microstructures features, phase identification and chemical composition of the alloy were analyzed by SEM, EDS, XRD and RA-IR to further understand the electrochemical behavior of the alloy. The results indicated that the self-passivation behavior of the alloy occurred universally and was obviously distinct with each other in different acidic artificial saliva. No phase transformation was observed and the oxide layer and corrosion products exhibited amorphous nature. There was an obvious complexation of the adsorbed albumin with the alloy, and the adsorption capacity of albumin increased with the prolongation of immersion time. The adsorbed albumin presenting black stripped spots had a certain inhibition to the formation of passivation film, and Ca2+ in saliva promoted the further adsorption of albumin as an intermediate bridge, going against the improvement of the corrosion resistance of passivation film/alloy system. In addition, the passivation state of the alloy surface was changed by different methods to investigate the adsorption behavior of albumin and its influence on the further passivation behavior in depth. Hitherto, we tried to propose a model to explain the dynamic adsorption process of albumin and its influencing mechanism on the growth behavior of passivation film.


Assuntos
Albuminas/química , Ligas de Cromo/química , Cobalto/química , Ligas Dentárias/química , Molibdênio/química , Saliva Artificial/química , Adsorção , Espectroscopia Dielétrica , Eletroquímica/métodos , Concentração de Íons de Hidrogênio , Teste de Materiais/métodos , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Difração de Raios X
18.
Dent Mater J ; 38(6): 963-969, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31434831

RESUMO

The aim of this study was to investigate the effects of artificial saliva on permeability measured using a highly sensitive digital flow meter of dentin discs treated with a phosphate containing desensitizer compound (Teethmate desensitizer; TD). Four random groups (n=10) were treated either with TD or distilled water (DW), then stored in artificial saliva (AS) or DW for 1 day, 1 week and 1 month. Flow rates under 2 kPa pressure were calculated as percentage reduction (PR%) from the baseline. The PR% of TD/AS group was significantly lower after 1 day and 1 week, but the PR%s of 1 month groups among TD/AS, TD/DW and DW/AS were not significantly different. The SEM photograph of TD/AS group displayed that the dentin surface was densely covered with mineral deposits. Ca and phosphate ions from the artificial saliva could penetrate into the tubules and precipitate as hydroxyapatite, resulting in the reduction in permeability.


Assuntos
Permeabilidade da Dentina , Sensibilidade da Dentina , Dentina , Humanos , Microscopia Eletrônica de Varredura , Permeabilidade , Saliva Artificial
19.
Indian J Dent Res ; 30(3): 393-398, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31397414

RESUMO

Background: The objectives were to evaluate the effect of surface treatments and waiting time before contact with dye on bleached enamel staining and surface treatments on roughness. Methods: One hundred bleached teeth were randomly assigned to G1 artificial saliva, G2 2% sodium fluoride (Flugel, Nova DFL), G3 casein phosphopeptide-amorphous calcium phosphate fluoride paste (MI Paste Plus, GC America), G4 rinse for bleached color maintenance (Keep White Rinse, DMC), and G5 polishing with impregnated disks (SuperBuff Disk, Shofu). Fifty specimens were immersed in coffee immediately after treatment; the others 1 h after. Color difference (ΔE) was evaluated with a spectrophotometer (Vita EasyShade) and roughness (Ra, Rq) with an optical profilometer (NewView 7300). Effects were analyzed with two-way ANOVA, Friedman, and Kruskal-Wallis test (P < 0.05). Results: Surface treatments (P = 0.878), waiting time (P = 0.105), and interaction (P = 0.145) were not significant to bleached color maintenance. Roughness was different among the evaluation time points (2nd evaluation >1st evaluation >3rd evaluation) (P < 0.001); not among surface treatments (G1, G2, G3, G4, G5) (P > 0.05). Conclusions: Surface treatments were similar to saliva for bleached enamel color maintenance. Immediate or 1-h postponed contact with coffee did not affect bleached enamel color. Bleaching increased enamel roughness; surface treatments and artificial saliva decreased it.


Assuntos
Clareadores Dentários , Clareamento Dental , Esmalte Dentário , Saliva Artificial , Coloração e Rotulagem
20.
J Contemp Dent Pract ; 20(4): 424-427, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31308271

RESUMO

INTRODUCTION: Bleached enamel surfaces may undergo changes and retain more dye, which is a reason to recommend the reduction/suspension of foods with dyes during dental bleaching. AIM: Evaluate the effects of the action of natural and artificial dyes on the bleached enamel of extracted human teeth. MATERIALS AND METHODS: Fifty human premolars were used, which were distributed in 5 groups (n = 10) according to the following staining solutions: GW (distilled water); GB (beet); Gca (caramel); GC (carmine); and GR (red 40). After the removal of the root and pulp section, the teeth were embedded in acrylic resin blocks, stored in artificial saliva, and kept at 37°C. At-home bleaching was performed using 16% carbamide peroxide (CP) for 3 hours daily for 3 weeks. After each daily session of bleaching, the specimens were exposed to the dye solution twice a day for 5 min; one of these exposures was performed immediately after bleaching. The color was recorded using a spectrophotometer according to the CIE Lab system (Δ E) for the following periods: baseline, during bleaching (after 1st, 2nd, and 3rd week) and post-bleaching (after 1 week and 1 month). The color was evaluated by two-way analysis of variance and Tukey's test (α=0.05). RESULTS: There was effective dental bleaching for all groups: GW (18.5 ± 6.1), GB (19.9 ± 4.4), Gca (18.9 ± 6.1), GC (20.2 ± 4.6), and GR (19.3 ± 4.2), p <0.01. No color rebound was observed after 1 week and 1 month (p >0.05). CONCLUSION: The exposure to beet, carmine, caramel, and red 40 dyes did not interfere with the effectiveness of dental bleaching using 16% CP. CLINICAL SIGNIFICANCE: Dyes consumption during bleaching did not affect the effectiveness of dental bleaching.


Assuntos
Clareadores Dentários , Clareamento Dental , Corantes , Humanos , Peróxidos , Saliva Artificial , Coloração e Rotulagem , Ureia
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