RESUMEN
The search for coatings that extend the useful life of biomedical devices has been of great interest, and titanium has been of great relevance due to its innocuousness and low reactivity. This study contributes to the investigation of Ti/Ag films in different configurations (monolayer and multilayer) deposited by magnetron sputtering. The sessile droplet technique was applied to study wettability; greater film penetrability was obtained when Ag is the external layer, conferring high efficiency in cell adhesion. The morphological properties were characterized by SEM, which showed porous nuclei on the surface in the Ag coating and crystals embedded in the Ti film. The structural properties were studied by XRD, revealing the presence of TiO2 in the anatase crystalline phase in a proportion of 49.9% and the formation of a silver cubic network centered on the faces. Tafel polarization curves demonstrated improvements in the corrosion current densities of Ag/Ti/Ag/Ti/Ag/Ti/Ag/Ti and Ti/Ag compared to the Ag coating, with values of 0.1749, 0.4802, and 2.044 nA.m-2, respectively. Antimicrobial activity was evaluated against the bacteria Pseudomonas aeruginosa and Bacillus subtilis and the yeasts Candida krusei and Candida albicans, revealing that the Ti/Ag and Ag/Ti/Ag/Ti/Ag/Ti/Ag/Ti coatings exhibit promise in biomedical material applications.
Asunto(s)
Materiales Biocompatibles Revestidos/química , Plata/farmacología , Titanio/farmacología , Humectabilidad/efectos de los fármacos , Antiinfecciosos/química , Antiinfecciosos/farmacología , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/patogenicidad , Candida/efectos de los fármacos , Candida/patogenicidad , Materiales Biocompatibles Revestidos/farmacología , Humanos , Ensayo de Materiales , Pichia/efectos de los fármacos , Pichia/patogenicidad , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/patogenicidad , Plata/química , Propiedades de Superficie , Titanio/químicaRESUMEN
The aim of this study was to evaluate the effect of spreading the lipopeptide surfactin, for short time (10/20 s), on dentin wettability. Study groups were surfactin: 2.8; 1.4; 0.7; 0.35; and 0.175 mg/mL and a control group that received no treatment. Dentin discs (4 mm height) were prepared and polished with 600-grit SiC paper. Contact angle determinations were carried out after microbrush spreading of surfactin on dentin specimens for, respectively, 10 and 20 s. Excess liquid was removed, and after 60 s, the specimens were analyzed in a goniometer using the sessile drop method to measure the contact angle. Results were analyzed by two-way ANOVA (concentration × time) and t student, with α = 0.05. Lower contact angles were obtained for surfactin (0.7 mg/mL) spread for 10 s. However, no statistical difference was observed for surfactin (2.8 mg/mL) applied during 20 s. Higher contact angles were observed for surfactin (0.7 mg/mL) spread for 20 s. In conclusion, dentin wettability is dependent on spreading time and surfactin concentration.
Asunto(s)
Dentina/química , Lipopéptidos/administración & dosificación , Péptidos Cíclicos/administración & dosificación , Diente/química , Humectabilidad/efectos de los fármacos , Dentina/efectos de los fármacos , Humanos , Ensayo de Materiales , Propiedades de SuperficieRESUMEN
This study investigated the effect of surfactants associated with sodium fluoride (NaF) on enamel erosion prevention, using an erosion-remineralization in vitro model. Sodium lauryl sulfate (SLS), polysorbate 20 (P20), and cocoamidopropyl betaine (CAPB) were tested, at concentrations of 1.0 and 1.5%, and associated or not with NaF (275 ppm). The control groups were distilled water and the NaF solution. Bovine enamel samples (n = 12) were prepared and submitted to a 5-day cycling model: acid challenge (0.3% citric acid, pH 2.6, 4×/day), human saliva (2 h, 4×/day), and the treatment solutions (2 min, 2×/day). The protective potential of the agents against initial erosion was assessed by microhardness and the surface loss by profilometry. Enamel surface wettability was determined by goniometry, protein adsorption was measured by spectroscopy (FTIR), and the KOH-soluble fluoride was quantified. Goniometry showed that SLS and CAPB increased enamel wettability. No differences were found among the surfactants regarding protein adsorption. Microhardness showed that SLS reduced NaF protection. P20 (1 and 1.5%) and CAPB 1.5% presented a protective effect, but lower than the NaF solution. Profilometry showed that CAPB protected enamel, but no agent associated with NaF promoted a higher protection than the NaF solution alone. KOH-soluble fluoride analysis showed that all surfactants reduced the fluoride adsorption on the enamel surface. Therefore, the surfactants tested (except for P20) changed the enamel surface energy. The SLS decreased the protective potential of NaF on initial erosion, but no tested agent interfered with the protective effect of NaF on enamel erosive wear.
Asunto(s)
Betaína/análogos & derivados , Cariostáticos/farmacología , Esmalte Dental/patología , Polisorbatos/farmacología , Dodecil Sulfato de Sodio/farmacología , Fluoruro de Sodio/farmacología , Tensoactivos/farmacología , Erosión de los Dientes/prevención & control , Adsorción/efectos de los fármacos , Análisis de Varianza , Animales , Betaína/química , Betaína/farmacología , Bovinos , Ácido Cítrico/efectos adversos , Esmalte Dental/efectos de los fármacos , Dureza , Polisorbatos/química , Saliva/fisiología , Dodecil Sulfato de Sodio/química , Tensoactivos/química , Erosión de los Dientes/inducido químicamente , Humectabilidad/efectos de los fármacos , Espectroscopía de Absorción de Rayos XRESUMEN
OBJECTIVE: To assess the effect of chitosan, at concentrations of 2.5% and 5.0%, on the wettability of the eroded dentin, followed by analysis of surface morphology by SEM. METHODS: 104 bovine dentin slabs were ground, polished and then immersed in 20mL of citric acid (pH=3.2) under continuous stirring for 2h. Specimens were randomly divided according to the dentin substrate: sound and eroded, and then, subdivided into 4 groups (n=10): without rewetting (control), 1% acetic acid, 2.5% chitosan and 5.0% chitosan. Then, a drop of the adhesive system Single Bond 2 (3M) was deposited onto surface of each specimen. The contact angle between dentin surface and the adhesive system was measured by using a goniometer. The other 24 specimens were subjected to analysis under SEM. Statistical analysis was performed using the normality test (Kolmogorov-Smirnov) and Analysis of Variance (ANOVA) (p>0.05). RESULTS: No differences were found between the angles produced on the eroded dentin rewetting with chitosan at the concentrations of 2.5% and 5%. CONCLUSION: The chitosan, regardless of the concentration used, did not influence the eroded dentin wettability. Through SEM analysis, it was found particles of chitosan deposited on the surface and within the dentinal tubules.
Asunto(s)
Quitosano/farmacología , Dentina/química , Erosión de los Dientes/patología , Ácido Acético , Análisis de Varianza , Animales , Bisfenol A Glicidil Metacrilato , Bovinos , Ácido Cítrico , Recubrimiento Dental Adhesivo , Dentina/diagnóstico por imagen , Dentina/patología , Recubrimientos Dentinarios/química , Incisivo/efectos de los fármacos , Microscopía Electrónica de Rastreo , Erosión de los Dientes/inducido químicamente , Erosión de los Dientes/diagnóstico por imagen , Humectabilidad/efectos de los fármacosRESUMEN
The surface properties of biomaterials, such as wettability, polar group distribution, and topography, play important roles in the behavior of cell adhesion and proliferation. Gaseous plasma discharges are among the most common means to modify the surface of a polymer without affecting its properties. Herein, we describe the surface modification of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA) films using atmospheric pressure plasma processing through exposure to a dielectric barrier discharge (DBD). After treatment the film surface showed significant changes from hydrophobic to hydrophilic as the water contact angle decreasing from 95° to 37°. All plasma-treated films developed more hydrophilic surfaces compared to untreated films, although the reasons for the change in the surface properties of PS and PMMA differed, that is, the PS showed chemical changes and in the case of PMMA they were topographical. Excellent adhesion and cell proliferation were observed in all films. In vitro studies employing flow cytometry showed that the proliferation of L929 cells was higher in the film formed by a 1:1 mixture of PS/PMMA, which is consistent with the results of a previous study. These findings suggest better adhesion of L929 onto the 1:1 PS/PMMA modified film, indicating that this system is a new candidate biomaterial for tissue engineering.
Asunto(s)
Fibroblastos/citología , Gases em Plasma/farmacología , Polimetil Metacrilato/farmacología , Poliestirenos/farmacología , Naranja de Acridina/metabolismo , Animales , Adhesión Celular/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Electricidad , Fibroblastos/efectos de los fármacos , Fibroblastos/ultraestructura , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Ratones , Microscopía de Fuerza Atómica , Termodinámica , Agua/química , Humectabilidad/efectos de los fármacosRESUMEN
INTRODUCTION: Gutta-percha (GP) and Resilon (Res) cones are usually disinfected by the use of solutions such as sodium hypochlorite (NaOCl) and chlorhexidine (CHX). The aims of this study were to evaluate the surface free energy of GP and Res cones after disinfection procedures and to investigate the wettability of endodontic sealers in contact with these surfaces. METHODS: GP and Res flat smooth surfaces were prepared. Thirty-six samples of each material were used. The samples were divided into 6 groups as follows: Control group GP, immersed in Milli-Q water (MQW); CHX group GP, immersed in 2% CHX solution and then washed with MQW; NaOCl group GP, immersed in 5.25% NaOCl and then washed with MQW; Control group Res, immersed in MQW; CHX group Res, immersed in 2% CHX solution and then washed with MQW; and NaOCl group Res, immersed in 5.25% NaOCl and then washed with MQW. Samples were analyzed first with a goniometer to measure the contact angle between the test surfaces and 3 solutions (water, ethylene glycol, and diiodomethane) to determine the surface free energy. Then the contact angle between surfaces and each one of the sealers tested, AH Plus and Real Seal SE, was measured. Data were statistically analyzed. RESULTS: The results showed that when disinfectant solutions were used, the surface free energy was greater. When evaluating the interaction between materials and sealers, the use of CHX presented lower values of contact angle, followed by NaOCl. CONCLUSIONS: It was concluded that the solutions used in decontamination increase the surface free energy, promoting high interaction between GP/Res and sealers.
Asunto(s)
Desinfectantes Dentales/química , Materiales de Obturación del Conducto Radicular/química , Irrigantes del Conducto Radicular/química , Humectabilidad/efectos de los fármacos , Descontaminación/métodos , Filtración Dental/prevención & control , Gutapercha/química , Propiedades de Superficie/efectos de los fármacosRESUMEN
Despite the many existing crosslinking procedures, glutaraldehyde (GA) is still the method of choice used in the manufacture of bioprosthesis. The major problems with GA are: (a) uncontrolled reactivity due to the chemical complexity or GA solutions; (b) toxicity due to the release of GA from polymeric crosslinks; and (c) tissue impermeabilization due to polymeric and heterogeneous crosslinks formation, partially responsible for the undesirable calcification of the bioprosthesis. A new method of crosslinking glutaraldehyde acetals has been developed with GA in acid ethanolic solution, and after the distribution inside de matrix, GA is released to crosslinking. Concentrations of hydrochloride acid in ethanolic solutions between 0.1 and 0.001 mol/L with GA concentration between 0.1 and 1.0% were measured in an ultraviolet spectrophotometer to verify the presence of free aldehyde groups and polymeric compounds of GA. After these measurements, the solutions were used to crosslink bovine pericardium. The spectrophotometric results showed that GA was better protected in acetal forms for acid ethanolic solution with HCl at 0.003 mol/L and GA 1.0%(v/v). The shrinkage temperature results of bovine pericardium crosslinked with acetal solutions showed values near 85 degrees C after the exposure to triethylamine vapors.
Asunto(s)
Acetales/farmacología , Colágeno/química , Colágeno/efectos de los fármacos , Glutaral/farmacología , Polímeros/síntesis química , Acetales/síntesis química , Acetales/química , Animales , Bovinos , Reactivos de Enlaces Cruzados/química , Reactivos de Enlaces Cruzados/farmacología , Análisis Diferencial Térmico , Elasticidad , Etanol/farmacología , Glutaral/química , Concentración de Iones de Hidrógeno , Modelos Biológicos , Pericardio/química , Pericardio/efectos de los fármacos , Pericardio/metabolismo , Polímeros/química , Espectrofotometría Ultravioleta , Temperatura , Ingeniería de Tejidos/métodos , Humectabilidad/efectos de los fármacosRESUMEN
A desinfecçäo de todo e qualquer molde obtido é medida de biossegurança obrigatória na atividade clínica. Täo importante quanto a desinfecçäo é a seleçäo do método e da soluçäo desinfetante a ser utilizada para cada material de moldagem. É imperativo que a capacidade de reproduçäo de detalhes, a estabilidade dimensional e o grau de umedecimento (ou "molhabilidade") näo sejam criticamente afetados. O propósito deste trabalho foi avaliar o grau de umedecimento de uma marca comercial de poliéter (Impregum F) por três diferentes marcas comerciais de gesso tipo IV (Herostone, Durone e Polirock), após sua desinfecçäo por aerossóis de hipoclorito de sódio 1 por cento (líquido de Milton) ou glutaraldeído 2 por cento (Glutalabor II). Foram confeccionados 45 moldes de poliéter, os quais, em grupos de 15, receberam aerossóis de água (Grupo Controle), Líquido de Milton ou Glutalabor II. Em seguida, sobre a superfície dos moldes foram confeccionados modelos de gesso tipo IV, em número de 5 para cada marca de gesso. Após seu seccionamento mediano e preparo da superfície de corte, os modelos foram levados ao microscópio Carl Zeiss para leitura do ângulo de contato. Os resultados obtidos permitiram concluir que: a) a capacidade de umedecimento do poliéter por diferentes marcas comerciais de gesso tipo IV variou para os gessos estudados; b) o gesso Durone adaptou-se melhor aos moldes de poliéter do que os gessos Herostone e Polirock; c) a desinfecçäo dos moldes com aerossóis de hipoclorito de sódio 1 por cento (líquido de Milton) ou glutaraldeído 2 por cento (Guatalabor) näo afetou a adaptaçäo entre os gessos e o poliéter