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1.
Bol. latinoam. Caribe plantas med. aromát ; 19(1): 65-76, ene. 2020. tab, ilus
Article in English | LILACS | ID: biblio-1102867

ABSTRACT

Due to the biological activities of Syzygium aromaticum essential oil, its incorporation in methacrylate polymeric (Eudragit E100) nanoparticles (NP), physical characterization, and antimicrobial essays were evaluated. The clove bears great potential for applications in dentistry. The oil was obtained by hydrodistillation and oil loaded NP using the nanoprecipitation method. Particle size and polydispersity index were determined by photon correlation spectroscopy, and physical morphology by electron microscopy. Loading capacity and in vitro eugenol release were evaluated by gas mass chromatography, and the antimicrobial activity of oil loaded-NP was calculated against Streptococcus mutans. Different chemical ingredients were characterized, and eugenol was the principal compound with 51.55%. Polymer content was directly related to NP homogenous size, which was around 150 nm with spherical morphology. A 73.2% loading capacity of eugenol was obtained. Oil loaded NP presented a fickian-type release mechanism of eugenol. Antimicrobial activity to 300 µg/mL was obtained after 24 h.


Debido a las actividades biológicas del aceite esencial de Syzygium aromaticum, se evaluó su incorporación en nanopartículas (NP) de metacrilato polimérico (Eudragit E100), su caracterización y ensayos antimicrobianos. El clavo tiene un gran potencial para aplicaciones en odontología. El aceite se obtuvo por hidrodestilación y las NP cargado de aceite utilizando el método de nanoprecipitación. El tamaño de partícula y el índice de polidispersidad se determinaron mediante espectroscopia de correlación fotónica y su morfología por microscopía electrónica. La capacidad de carga y la liberación de eugenol in vitro se evaluaron mediante cromatografía de gases en masa, y la actividad antimicrobiana se evaluó contra Streptococcus mutans. Se caracterizaron diferentes ingredientes químicos, siendo el eugenol el principal compuesto con 51.55%. El contenido de polímero se relacionó directamente con el tamaño homogéneo de NP, que fue de alrededor de 150 nm con morfología esférica. Se obtuvo un 73,2% de capacidad de carga de eugenol. El aceite cargado en NP presentó un mecanismo de liberación de eugenol de tipo fickiano. La actividad antimicrobiana a 300 µg/mL se obtuvo después de 24 h.


Subject(s)
Polymers/chemistry , Oils, Volatile/administration & dosage , Syzygium/chemistry , Nanoparticles/chemistry , Anti-Bacterial Agents/administration & dosage , Streptococcus mutans/drug effects , Eugenol/pharmacology , Oils, Volatile/pharmacology , Administration, Oral , Chromatography, Thin Layer , Drug Delivery Systems , Gas Chromatography-Mass Spectrometry , Anti-Bacterial Agents/pharmacology
2.
Electron. j. biotechnol ; 38: 49-57, Mar. 2019. tab, graf, ilus
Article in English | LILACS | ID: biblio-1051388

ABSTRACT

BACKGROUND: This paper presents micro- and nano-fabrication techniques for leachable realgar using the extremophilic bacterium Acidithiobacillus ferrooxidans (A. ferrooxidans) DLC-5. RESULTS: Realgar nanoparticles of size ranging from 120 nm to 200 nm were successfully prepared using the highenergy ball mill instrument. A. ferrooxidans DLC-5 was then used to bioleach the particles. The arsenic concentration in the bioleaching system was found to be increased significantly when compared with that in the sterile control. Furthermore, in the comparison with the bioleaching of raw realgar, nanoparticles could achieve the same effect with only one fifth of the consumption. CONCLUSION: Emphasis was placed on improving the dissolvability of arsenic because of the great potential of leachable realgar drug delivery in both laboratory and industrial settings


Subject(s)
Arsenic/metabolism , Sulfides/metabolism , Acidithiobacillus/metabolism , Mining/methods , Arsenic/chemistry , Solubility , Sulfides/chemistry , Temperature , Nanotechnology , Nanoparticles/chemistry , Extremophiles
3.
J. oral res. (Impresa) ; 8(1): 37-41, feb. 28, 2019. tab, ilus
Article in English | LILACS | ID: biblio-1145265

ABSTRACT

Background: Auto-polymerized acrylic resins are commonly used in many applications in dentistry including in maxillofacial rehabilitation such as interim prostheses, denture repair, reline, orthodontic appliances, record base, among others. These substances, however, have some negative aspects such as poor mechanical properties. Aim: The objective of the current study was to evaluate the effect of incorporating zinc oxide nanoparticles to auto-polymerized acrylic resins on their flexural strength. Materials and methods: Thirty specimens were made from auto-polymerized acrylic resins, divided into three main groups (1 control and 2 experimental). Each group had ten specimens. The two experimental groups comprised the zinc oxide powder at 1% and 2% concentrations, respectively. Acrylic specimens were fabricated with the dimension of 65mm length, 10mm width and 2.5mm thickness according to ISO 1567 specification 1999. Each specimen was subjected to the flexural strength test by a universal testing machine. The crosshead speed for the flexural strength test was 5mm/min until fracture occurred. The SPSS version 16 was utilized for the statistical analysis. The ANOVA and Tukey were used for the comparison among all groups. Results: there was a significant increase (p<0.001) in the flexural strength of the acrylic resins following the addition of zinc oxide particles (control group: 133.27 SD 1.73, ZnO 1%: 154.28 SD 2.90, ZnO 2%: 176.45 SD 0.94). Conclusions: The incorporation of zinc oxide nanoparticles has a significant effect on the flexural strength of auto-polymerized acrylic resins.


Antecedentes: Las resinas acrílicas autopolimerizadas se usan comúnmente en muchas aplicaciones en odontología, incluyendo la rehabilitación maxilofacial, en prótesis provisionales, reparación de prótesis, revestimientos, en aparatos de ortodoncia, bases de registro, entre otros. Estas sustancias, sin embargo, tienen algunos aspectos negativos tales como propiedades mecánicas deficientes. Objetivo: el objetivo del presente estudio fue evaluar el efecto de la incorporación de nanopartículas de óxido de zinc en la resistencia a la flexión de resinas acrílicas autopolimerizadas. Materiales y métodos: Treinta muestras de resinas acrílicas autopolimerizadas fueron hechas, divididas en tres grupos principales (un grupo control y dos experimentales), cada grupo con diez especímenes. Se incorporó polvo de óxido de zinc en los dos grupos experimentales, en concentraciones de 1% y 2%, respectivamente. Las muestras de acrílico se fabricaron con una dimensión de 65mm de longitud, 10mm de ancho y 2,5mm de espesor según la especificación ISO 1567 1999. Cada muestra se sometió a la prueba de resistencia a la flexión mediante una máquina de prueba universal. La velocidad de la cruceta para la prueba de resistencia a la flexión fue de 5mm/min hasta que se produjo la fractura. Se utilizó la versión SPSS 16 para el análisis estadístico. El ANOVA y Tukey se utilizaron para la comparación entre todos los grupos. Resultados: Se observó un aumento significativo (p<0.0 01) en la resistencia a la flexión de las resinas acrílicas luego de la adición de partículas de óxido de zinc (grupo de control: 133,27 SD 1,73 MPa, ZnO 1%: 154,28 SD 2,90 MPa, ZnO 2%: 176,45 SD 0,94 MPa). Conclusiones: La incorporación de nanopartículas de óxido de zinc tiene un efecto significativo en la resistencia a la flexión de las resinas acrílicas autopolimerizadas.


Subject(s)
Humans , Zinc Oxide , Acrylic Resins/chemistry , Dental Materials/chemistry , Nanoparticles/chemistry , Outcome Assessment, Health Care , Flexural Strength
4.
Int. j. morphol ; 36(4): 1463-1471, Dec. 2018. graf
Article in Spanish | LILACS | ID: biblio-975723

ABSTRACT

Los materiales poliméricos han sido ampliamente investigados para aplicaciones biomédicas, teniendo especial relevancia cuando se encuentran en forma de micro- y nano-partículas. Últimamente se ha ampliado su campo de aplicación al ser conjugados con péptidos y ácidos nucleicos, por lo tanto, el interés en el estudio de este tipo de materiales, así como también en la formulación de nanoestructuras funcionalizadas como materiales, dispositivos y vehículos de transporte de agentes terapéuticos ha aumentado. Las recientes investigaciones en nanosistemas se inspiran en fenómenos naturales que estimulan la integración de señales moleculares y la mimetización de procesos a nivel celular, de tejidos y órganos. Tecnológicamente, la capacidad de obtener nanoestructuras esféricas mediante la combinación de materiales que presenten propiedades distintas a las que ningún otro material individual posee por sí solo, es lo que hace que las nanocápsulas sean particularmente atractivas. Las potenciales ventajas de los sistemas de nanopartículas de tipo polimérico se destacan a lo largo de cada parte de este artículo de revisión. El presente artículo aborda los aspectos más relevantes sobre la estructura, composición y algunos métodos de elaboración de los sistemas nanoparticulados. Además, expone algunos de los trabajos más recientes, centrados en sistemas de nanopartículas basados en polímeros dirigidos a la administración de agentes, publicados en artículos especializados de investigación y revisiones durante los últimos años.


Polymeric materials have been extensively investigated for biomedical applications including micro- and nanoparticles. Modern advances have broadened horizons for application with peptides and nucleic acids. Therefore, interests increased in the formulation of materials, devices and vehicles for transporting therapeutic agents in functionalized nanostructures. Recent nano-systems are inspired by natural phenomena that stimulate the integration of molecular signals and the mimicking of natural cellular processes, at tissue and organ levels. Technologically, the ability to obtain spherical nanostructures, which combine different properties, that no other single material possesses on its own, makes nanocapsules particularly attractive. Potential advantages over polymer nanoparticulate systems are highlighted throughout each part of this review article. Here, we address the most relevant aspects of structure, composition and methods of formulation of nanoparticulate systems. In addition, we outline some of the more recent works focusing on nanosized preparations, based on agent-directed polymers, found in specialized research articles that have emerged in the recent years.


Subject(s)
Polymers/chemistry , Nanoparticles/chemistry , Drug Delivery Systems , Tissue Engineering , Quantum Dots , Nanocapsules/chemistry , Nanospheres/chemistry
5.
J. appl. oral sci ; 26: e20170270, 2018. tab, graf
Article in English | LILACS, BBO | ID: biblio-893712

ABSTRACT

Abstract Although resin composites are widely used in the clinical practice, the development of recurrent caries at composite-tooth interface still remains as one of the principal shortcomings to be overcome in this field. Objectives To evaluate the activity against S. mutans biofilm of model resin composites incorporating different concentrations of ZnO-nanoparticles (ZnO-NP) and characterize their physicochemical properties. Materials and Methods Different concentrations of ZnO-NP (wt.%): E1=0, E2=0.5, E3=1, E4=2, E5=5 and E6=10 were incorporated into a model resin composite consisting of Bis-GMA-TEGDMA and barium borosilicate particles. The activity against S. mutans biofilm was evaluated by metabolic activity and lactic acid production. The following physicochemical properties were characterized: degree of conversion (DC%), flexural strength (FS), elastic modulus (EM), hardness (KHN), water sorption (Wsp), water solubility (Wsl) and translucency (TP). Results E3, E4, E5 and E6 decreased the biofilm metabolic activity and E5 and E6 decreased the lactic acid production (p<0.05). E6 presented the lowest DC% (p<0.05). No significant difference in FS and EM was found for all resin composites (p>0.05). E5 and E6 presented the lowest values of KHN (p<0.05). E6 presented a higher Wsp than E1 (p<0.05) and the highest Wsl (p<0.05). The translucency significantly decreased as the ZnO- NP concentration increased (p<0.05). Conclusions The incorporation of 2 - 5 wt.% of ZnO-NP could endow antibacterial activity to resin composites, without jeopardizing their physicochemical properties.


Subject(s)
Streptococcus mutans/drug effects , Zinc Oxide/pharmacology , Zinc Oxide/chemistry , Composite Resins/pharmacology , Composite Resins/chemistry , Nanoparticles/chemistry , Polyethylene Glycols/pharmacology , Polyethylene Glycols/chemistry , Polymethacrylic Acids/pharmacology , Polymethacrylic Acids/chemistry , Reference Values , Solubility , Streptococcus mutans/growth & development , Surface Properties , Materials Testing , Water/chemistry , Microscopy, Electron, Scanning , Linear Models , Reproducibility of Results , Analysis of Variance , Bisphenol A-Glycidyl Methacrylate/pharmacology , Bisphenol A-Glycidyl Methacrylate/chemistry , Silicates/pharmacology , Silicates/chemistry , Barium Compounds/pharmacology , Barium Compounds/chemistry , Pliability , Biofilms/growth & development , Biofilms/drug effects , Elastic Modulus , Hardness Tests
6.
Braz. J. Pharm. Sci. (Online) ; 54(1): e17314, 2018. graf
Article in English | LILACS | ID: biblio-951904

ABSTRACT

Abstract Mucoadhesive nanoparticles are particularly interesting for delivery through nasal or pulmonary routes, as an approach to overcome the mucociliary clearance. Moreover, these nanoparticles are attractive for peptide and protein delivery, particularly for insulin to treat diabetes, as an alternative to conventional parenteral administration. Thus, chitosan, a cationic mucoadhesive polysaccharide found in shells of crustaceans, and the negatively-charged dextran sulfate are able to form nanoparticles through ionic condensation, representing a potential insulin carrier. Herein, chitosan/dextran sulfate nanoparticles at various ratios were prepared for insulin loading. Formulations were characterized for particle size, zeta potential, encapsulation efficiency, scanning electron microscopy, differential scanning calorimetry, and in vitro drug release. Moreover, the interaction with mucin and the cytotoxicity against a lung cell line were studied, which altogether have not been addressed before. Results evidenced that a proper selection of polyelectrolytes is necessary for smaller particle size formation and also the composition and zeta potential impact encapsulation efficiency, which is benefited by the positive charge of chitosan. Insulin remained stable after encapsulation as evidenced by calorimetric assays, and was released in a sustained manner in the first 10 h. Positively-charged nanoparticles based on chitosan/dextran-sulfate at the ratio of 6:4 successfully interacted with mucin, which is a prerequisite for delivery to mucus-containing tissues. Finally, insulin-loaded nanoparticles displayed no cytotoxicity effect against lung cells at tested concentrations, suggesting the potential for further in vivo studies.


Subject(s)
Nanoparticles/chemistry , Insulysin/analysis , Dextrans , Chitosan , Diabetes Mellitus/drug therapy , Polyelectrolytes/classification
7.
Electron. j. biotechnol ; 27: 84-90, May. 2017. graf, ilus, tab
Article in English | LILACS | ID: biblio-1010412

ABSTRACT

Background: Iron magnetic nanoparticles have attracted much attention. They have been used in enzyme immobilization because of their properties such as product is easily separated from the medium by magnetic separation. The present work was designed to immobilize horseradish peroxidase on Fe3O4 magnetic nanopraticles without modification. Results: In the present study, horseradish peroxidase (HRP) was immobilized on non-modified Fe3O4 magnetic nanoparticles. The immobilized HRP was characterized by FT-IR spectroscopy, scanning electron microscopy, and energy dispersive X-ray. In addition, it retained 55% of its initial activity after 10 reuses. The optimal pH shifted from 7.0 for soluble HRP to 7.5 for the immobilized HRP, and the optimal temperature shifted from 40°C to 50°C. The immobilized HRP is more thermostable than soluble HRP. Various substrates were oxidized by the immobilized HRP with higher efficiencies than by soluble HRP. Km values of the soluble and immobilized HRP were 31 and 45 mM for guaiacol and 5.0 and 7.0 mM for H2O2, respectively. The effect of metals on soluble and immobilized HRP was studied. Moreover, the immobilized HRP was more stable against high concentrations of urea, Triton X-100, and isopropanol. Conclusions: Physical immobilization of HRP on iron magnetic nanoparticles improved the stability toward the denaturation induced by pH, heat, metal ions, urea, detergent, and water-miscible organic solvent.


Subject(s)
Enzymes, Immobilized/chemistry , Ferrosoferric Oxide/chemistry , Horseradish Peroxidase/chemistry , Solubility , Spectrometry, X-Ray Emission , Temperature , Microscopy, Electron, Scanning , Spectroscopy, Fourier Transform Infrared , Enzymes, Immobilized/metabolism , Nanoparticles/chemistry , Horseradish Peroxidase/metabolism , Hydrogen-Ion Concentration
8.
J. appl. oral sci ; 25(2): 177-185, Mar.-Apr. 2017. graf
Article in English | LILACS, BBO | ID: biblio-841179

ABSTRACT

Abstract Objective To prepare nanocomposite cements based on the incorporation of bioactive glass nanoparticles (nBGs) into BiodentineTM (BD, Septodent, Saint-Maur-des-Fosses Cedex, France) and to assess their bioactive properties. Material and Methods nBGs were synthesised by the sol-gel method. BD nanocomposites (nBG/BD) were prepared with 1 and 2% nBGs by weight; unmodified BD and GC Fuji IX (GIC, GC Corporation, Tokyo, Japan) were used as references. The in vitro ability of the materials to induce apatite formation was assessed in SBF by X-ray diffraction (XRD), attenuated total reflectance with Fourier transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. BD and nBG/BD were also applied to dentine discs for seven days; the morphology and elemental composition of the dentine-cement interface were analysed using SEM-EDX. Results One and two percent nBG/BD composites accelerated apatite formation on the disc surface after short-term immersion in SBF. Apatite was detected on the nBG/BD nanocomposites after three days, compared with seven days for unmodified BD. No apatite formation was detected on the GIC surface. nBG/BD formed a wider interfacial area with dentine than BD, showing blockage of dentine tubules and Si incorporation, suggesting intratubular precipitation. Conclusions The incorporation of nBGs into BD improves its in vitro bioactivity, accelerating the formation of a crystalline apatite layer on its surface after immersion in SBF. Compared with unmodified BD, nBG/BD showed a wider interfacial area with greater Si incorporation and intratubular precipitation of deposits when immersed in SBF.


Subject(s)
Humans , Silicates/chemistry , Calcium Compounds/chemistry , Dentin/drug effects , Nanoparticles/chemistry , Glass Ionomer Cements/chemistry , Apatites/chemistry , Spectrometry, X-Ray Emission , Surface Properties/drug effects , Time Factors , X-Ray Diffraction , Materials Testing , Microscopy, Electron, Scanning , Reproducibility of Results , Spectroscopy, Fourier Transform Infrared , Statistics, Nonparametric , Resin Cements/chemistry , Immersion
9.
Braz. dent. j ; 28(2): 172-178, mar.-Apr. 2017. tab, graf
Article in Portuguese | LILACS | ID: biblio-839144

ABSTRACT

Resumo Os novos materiais restauradores em desenvolvimento devem evitar danos aos tecidos dentários. Portanto, o objetivo deste estudo foi avaliar a biocompatibilidade de uma marca comercial de cimento de ionômero de vidro convencional (CIV) modificado com microfibras de celulose (CIV+MC) ou nanocristais de celulose (CIV+NC) através da implantação de três amostras em tecido subcutâneo na região dorsal de 15 ratos Rattus norvegicus albinus. Cada rato recebeu um exemplar de cada cimento, resultando nos seguintes grupos (n=15): Grupo CIV (controle, n=15), Grupo CIV+MC e Grupo CIV+NC. Nos intervalos de 7, 30 e 60 dias os animais foram sacrificados e os seguintes aspectos foram avaliados histologicamente: tipo de células inflamatórias, fibroblastos, vasos sanguíneos, macrófagos, células gigantes, tipo de reação inflamatória e espessura da cápsula (µm). Estes eventos foram quantitativamente classificados conforme os escores: (-) ausente, (+) suave, (++) moderado e (+++) intenso. Os resultados foram analisados estatisticamente pelo teste Kruskal-Wallis e pós-teste Mann-Whitney. Aos 7 dias, o Grupo CIV+NC demonstrou um nível mais elevado de reparação tecidual porque havia maior quantidade de fibroblastos (p=0,022) e uma menor quantidade de macrófagos (p=0,008) e células mononucleares (p=0,033). Neutrófilos e células gigantes estavam ausentes em todos os períodos experimentais. Aos 60 dias, o Grupo CIV+NC apresentou cápsula de tecido fibroso com espessura mais reduzida (26,72±2,87 µm) em comparação ao Grupo CIV+MC (41,21±3,98 µm (p=0,025). No geral, todos os materiais apresentaram satisfatória biocompatibilidade, no entanto, o cimento de ionômero de vidro modificado com nanocristais de celulose proveu reparação tecidual mais avançada comparativamente aos demais materiais avaliados.


Developing new restorative materials should avoid damage to tissue structures. This study evaluated the biocompatibility of a commercial dental glass ionomer cement (GIC) mechanically reinforced with cellulose microfibers (GIC+CM) or cellulose nanocrystals (GIC+CN) by implantation of three test specimens in subcutaneous tissue in the dorsal region of 15 Rattus norvegicus albinus rats. Each rat received one specimen of each cement, resulting in the following groups (n=15): Group GIC (Control), Group GIC+CM and Group GIC+NC. After time intervals of 7, 30 and 60 days, the animals were sacrificed and the following aspects were histologically evaluated: type of inflammatory cells, fibroblasts, blood vessels, macrophages, giant cells, type of inflammatory reaction and capsule thickness (µm). These events were scored as (-) absent, (+) light, (++) moderate and (+++) intense. The results were statistically analyzed by Kruskal-Wallis test and Mann-Whitney post test. At 7 days, Group GIC+NC showed more favorable tissue repair because quantitatively there were more fibroblasts (p=0.022), fewer macrophages (p=0.008) and mononuclear cells (p=0.033). Polymorphonuclear neutrophils and giant cells were absent in all experimental periods. At 60 days, test specimens in Group GIC+NC were surrounded by a fibrous tissue capsule with reduced thickness (26.72±2.87 µm) in comparison with Group GIC+CM (41.21±3.98 µm) (p=0.025). In general, all biomaterials showed satisfactory biocompatibility, but glass ionomer cement modified with cellulose nanocrystals showed a more advanced tissue repair.


Subject(s)
Animals , Rats , Biocompatible Materials , Cellulose/chemistry , Nanoparticles/chemistry , Glass Ionomer Cements/chemistry
10.
Int. j. morphol ; 35(1): 26-33, Mar. 2017. ilus
Article in Spanish | LILACS | ID: biblio-840927

ABSTRACT

En los últimos años microorganismos tales como hongos, levaduras y, en especial, las bacterias han sido utilizadas para realizar biosíntesis de nanopartículas. Existen varios tipos de bacterias descritas como productoras de nanopartículas, sin embargo, las bacterias psicrófilas y psicrotolerantes no han sido ampliamente estudiadas, aun cuando su utilización en la producción de nanopartículas podría entregar ventajas relacionadas con su estabilidad, el gasto energético de su producción, al mismo tiempo que son una alternativa amigable con el medio ambiente. Este artículo entrega una breve revisión de las bacterias antárticas psicrófilas y psicrotolerantes sintetizadoras de nanopartículas, los posibles mecanismos que se asocian a esta síntesis y perspectivas futuras relacionadas a la biosíntesis bacteriana de nanopartículas.


In recent years microorganisms as fungi, yeasts and especially bacteria have been used to produce nanoparticles biosynthesis. Several types of bacteria are described as nanoparticles producers, however, psychrophilic and psychrotolerant bacterias have not been studied widely, although its use in the production of nanoparticles could provide advantages related to the stability of nanoparticles, energy expenditure on its production, while being an environmentally friendly alternative. This article provides a brief overview of Antarctic bacterias, both psychrophilic and psychrotolerant that synthesis nanoparticles, possible mechanisms associated to this synthesis and future perspectives related to bacterial biosynthesis of nanoparticles.


Subject(s)
Bacteria/metabolism , Nanoparticles/chemistry
11.
Braz. j. med. biol. res ; 50(10): e6225, 2017. tab, graf
Article in English | LILACS | ID: biblio-888940

ABSTRACT

Coronary allograft vasculopathy is an inflammatory-proliferative process that compromises the long-term success of heart transplantation and has no effective treatment. A lipid nanoemulsion (LDE) can carry chemotherapeutic agents in the circulation and concentrates them in the heart graft. The aim of the study was to investigate the effects of methotrexate (MTX) associated to LDE. Rabbits fed a 0.5% cholesterol diet and submitted to heterotopic heart transplantation were treated with cyclosporine A (10 mg·kg-1·day-1 orally) and allocated to treatment with intravenous LDE-MTX (4 mg/kg, weekly, n=10) or with weekly intravenous saline solution (control group, n=10), beginning on the day of surgery. Animals were euthanized 6 weeks later. Compared to controls, grafts of LDE-MTX treated rabbits showed 20% reduction of coronary stenosis, with a four-fold increase in vessel lumen and 80% reduction of macrophage staining in grafts. Necrosis was attenuated by LDE-MTX. Native hearts of both LDE-MTX and Control groups were apparently normal. Gene expression of lipoprotein receptors was significantly greater in grafts compared to native hearts. In LDE-MTX group, gene expression of the pro-inflammatory factors tumor necrosis factor-α, monocyte chemoattractant protein-1, interleukin-18, vascular cell adhesion molecule-1, and matrix metalloproteinase-12 was strongly diminished whereas expression of anti-inflammatory interleukin-10 increased. LDE-MTX promoted improvement of the cardiac allograft vasculopathy and diminished inflammation in heart grafts.


Subject(s)
Animals , Rabbits , Graft Rejection/prevention & control , Heart Transplantation/adverse effects , Immunosuppressive Agents/administration & dosage , Lipids/administration & dosage , Methotrexate/administration & dosage , Nanoparticles/administration & dosage , Allografts , Immunosuppressive Agents/pharmacology , Methotrexate/pharmacology , Nanoparticles/chemistry
12.
J. appl. oral sci ; 24(3): 204-210, tab, graf
Article in English | LILACS, BBO | ID: lil-787546

ABSTRACT

ABSTRACT Objective Mineral Trioxide Aggregate (MTA) is a calcium silicate cement composed of Portland cement (PC) and bismuth oxide. Hydroxyapatite has been incorporated to enhance mechanical and biological properties of dental materials. This study evaluated physicochemical and mechanical properties and antibiofilm activity of MTA and PC associated with zirconium oxide (ZrO2) and hydroxyapatite nanoparticles (HAn). Material and Methods White MTA (Angelus, Brazil); PC (70%)+ZrO2 (30%); PC (60%)+ZrO2 (30%)+HAn (10%); PC (50%)+ZrO2 (30%)+HAn (20%) were evaluated. The pH was assessed by a digital pH-meter and solubility by mass loss. Setting time was evaluated by using Gilmore needles. Compressive strength was analyzed by mechanical test. Samples were radiographed alongside an aluminum step wedge to evaluate radiopacity. For the antibiofilm evaluation, materials were placed in direct contact with E. faecalis biofilm induced on dentine blocks. The number of colony-forming units (CFU mL-1) in the remaining biolfilm was evaluated. The results were submitted to ANOVA and the Tukey test, with 5% significance. Results There was no difference in pH levels of PC+ZrO2, PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p>0.05) and these cements presented higher pH levels than MTA (p<0.05). The highest solubility was observed in PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p<0.05). MTA had the shortest initial setting time (p<0.05). All the materials showed radiopacity higher than 3 mmAl. PC+ZrO2 and MTA had the highest compressive strength (p<0.05). Materials did not completely neutralize the bacterial biofilm, but the association with HAn provided greater bacterial reduction than MTA and PC+ZrO2 (p<0.05) after the post-manipulation period of 2 days. Conclusions The addition of HAn to PC associated with ZrO2 harmed the compressive strength and solubility. On the other hand, HAn did not change the pH and the initial setting time, but improved the radiopacity (HAn 10%), the final setting time and the E. faecalis antibiofilm activity of the cement.


Subject(s)
Oxides/chemistry , Zirconium/chemistry , Enterococcus faecalis/drug effects , Silicates/chemistry , Durapatite/chemistry , Calcium Compounds/chemistry , Aluminum Compounds/chemistry , Biofilms/drug effects , Nanoparticles/chemistry , Oxides/pharmacology , Solubility , Time Factors , Zirconium/pharmacology , Bismuth/pharmacology , Bismuth/chemistry , Materials Testing , Colony Count, Microbial , Analysis of Variance , Enterococcus faecalis/growth & development , Silicates/pharmacology , Durapatite/pharmacology , Calcium Compounds/pharmacology , Aluminum Compounds/pharmacology , Compressive Strength , Dental Cements/pharmacology , Dental Cements/chemistry , Drug Combinations , Hydrogen-Ion Concentration
14.
Rev. chil. pediatr ; 86(4): 236-243, ago. 2015. ilus, tab
Article in Spanish | LILACS | ID: lil-764079

ABSTRACT

Introducción: La respuesta inmune a los antígenos de las vacunas está disminuida en los niños con cáncer. El objetivo de este estudio fue evaluar la seroconversión frente a vacuna ADN recombinante contra hepatitis B al momento del inicio de la quimioterapia y/o remisión en niños con cáncer. Pacientes y método: Estudio prospectivo, bicéntrico, controlado, no aleatorizado de niños con diagnóstico reciente de cáncer pareados con niños sanos. Los casos fueron vacunados a tiempo 0, 1 y 6 meses, a dosis de 20 y 40 μg si eran < ó > 10 años, respectivamente, con vacuna ADN recombinante contra hepatitis B, en el momento del diagnóstico en el caso de los tumores sólidos y luego de la remisión en el caso de los tumores hematológicos. El grupo control recibió el mismo esquema, con dosis de 10 o 20 μg respectivamente. Se midieron anticuerpos séricos anti-HBs a los 2, 8 y 12 meses posvacunación. Seroconversión se definió como títulos anti-HBs > 10 mUI/ml al octavo mes. Resultados: Un total de 78 niños con cáncer y 25 controles fueron evaluados con títulos anti-HBs al octavo mes. La tasa de seroconversión fue de 26,9%, en niños con cáncer, sin diferencia por edad, género ni tipo de tumor (p = 0,13; 0,29; y 0,44, respectivamente), y de 100% en el grupo control (p < 0,0001, comparado con los niños con cáncer). En el seguimiento a los 12 meses solo el 31,9% de los niños con cáncer presentaba títulos anti-HBs > 10 mUI/ml. Conclusiones: La vacunación contra hepatitis B con vacuna ADN recombinante, con esquema reforzado de 3 dosis, en el momento del inicio de la quimioterapia y/o remisión provee una respuesta inmune insuficiente en la mayoría de los niños con cáncer. En esta población debieran evaluarse vacunas de tercera generación, con adyuvantes más inmunogénicos, esquemas reforzados a los 0, 1, 2 y 6 meses, medición de títulos de anticuerpos al octavo y duodécimo mes, eventual uso de refuerzos y reevaluación de inmunogenicidad si correspondiese.


Introduction: Immune response against vaccine antigens may be impaired in children with cancer. The aim of this study was to evaluate the seroconversion response against hepatitis B vaccination (HBV) at the time of chemotherapy onset and/or remission in children with cancer. Patients and method: Prospective, two-centre, controlled, non-randomised study conducted on children recently diagnosed with cancer, paired with healthy subjects. Cases received HBV at time 0, 1 and 6 months with DNA recombinant HBV at a dose of 20 and 40 μg if < or > than 10 years of age, respectively, at the time of diagnosis for solids tumours and after the remission in case of haematological tumours. Controls received the same schedule, but at of 10 and 20 μg doses, respectively. HBs antibodies were measured in serum samples obtained at 2, 8 and 12 months post-vaccination. Protective titres were defined as > 10 mIU/ml at 8th month of follow up. Results: A total of 78 children with cancer and 25 healthy controls were analysed at month 8th of follow up. Seroconversion rates in the cancer group reached 26.9%, with no differences by age, gender or type of tumour (P = .13, .29, and .44, respectively). Control group seroconversion was 100% at the 8th month, with P < .0001 compared with the cancer group. At month 12 of follow up, just 31.9% of children with cancer achieved anti-HBs antibodies > 10 mIU/ml. Conclusions: Vaccination against hepatitis B with three doses of DNA recombinant vaccine at an increased concentration, administrated at the time of onset of chemotherapy and/or remission provided an insufficient immune response in a majority of children with cancer. More immunogenic vaccines should be evaluated in this special population, such as a third generation, with more immunogenic adjuvants, enhanced schedules at 0, 1, 2, 6 month, evaluation of antibody titres at month 8 and 12 h to evaluate the need for further booster doses.


Subject(s)
Humans , HIV , Anti-HIV Agents/immunology , Anti-HIV Agents/pharmacology , /immunology , HIV Infections/drug therapy , Liposomes/immunology , Liposomes/pharmacology , HIV , Antiretroviral Therapy, Highly Active/methods , Drug Carriers/chemistry , HIV Infections/immunology , HIV Protease Inhibitors/immunology , HIV Protease Inhibitors/pharmacology , Jurkat Cells , Lipids/chemistry , Lipids/immunology , Nanoparticles/chemistry , Nevirapine/immunology , Nevirapine/pharmacology , Saquinavir/immunology , Saquinavir/pharmacology
15.
Rev. chil. pediatr ; 86(4): 244-250, ago. 2015. tab
Article in Spanish | LILACS | ID: lil-764080

ABSTRACT

Objetivo: Caracterizar la hospitalización por episodios de cianosis en recién nacidos (RN) > 34 semanas. Pacientes y método: Estudio retrospectivo que incluyó la totalidad de los RN hospitalizados por episodios de cianosis entre enero de 2007 y diciembre de 2012. En ellos se aplicaron 2 protocolos de estudio que consideraban exámenes de primera y segunda línea; estos últimos ante la recurrencia de eventos. El protocolo de primera línea consideró exámenes bioquímicos generales, radiografía de tórax y ecocardiografía en casos seleccionados, en tanto que el protocolo de segunda línea incluyó electroencefalograma, electrocardiograma, resonancia magnética nuclear encefálica, screening metabólico ampliado, ácido pirúvico, ácido láctico y en caso de convulsiones, citoquímico y cultivo de líquido cefalorraquídeo y reacción en cadena de la polimerasa para herpes. Resultados: Noventa y ocho de un total de 3.454 (2,8%) RN hospitalizados ingresaron por episodio de cianosis. La edad gestacional (EG) fue 37,8 + 1,36 semanas; peso al nacimiento: 3145 + 477 g. Edad materna: 32 + 4,8 años. El 19,4% de las madres tenía antecedentes mórbidos: diabetes gestacional (8,1%), síndrome hipertensivo del embarazo (5,1%), colestasia intrahepática (3,1%) y retardo del crecimiento (3,1%). Género: 48,8% masculino, parto por cesárea: 68,4%. Edad al ingreso: 1,9 + 1,4 días; duración de la hospitalización: 4,2 + 4,2 días. En todos los pacientes se practicaron exámenes de primera línea y en el 39,8% exámenes de segunda línea. En el 21,4% de los RN se identificó una causa, siendo el síndrome convulsivo el más frecuente (33%). Los RN con diagnóstico asociado presentaron 3,8 + 2,7 episodios de cianosis versus 1,5 + 2,4 en el grupo sin diagnóstico (NS). El 15,4% se fueron de alta con monitor; no hubo reingresos. Conclusión: La incidencia de hospitalización neonatal por episodios de cianosis fue de 6 por 1.000 RN vivos. Solo en cerca de un 20% de ellos es posible identificar una causa, siendo la más frecuente el síndrome convulsivo.


Objectives: A retrospective study was performed between January 2007 and December 2012 to assess the admission rates of newborns due to episodes of cyanosis Patients and method: Retrospective study that included all the newborns hospitalized with episodes of cyanosis between January 2007 and December 2012. In them were employed two study protocols that considered first and second line tests, the latter in view of recurrence of events. The first line protocol considered general biochemical tests, chest x-ray and echocardiography in selected cases, while the second line protocol included electroencephalogram, electrocardiogram, nuclear magnetic resonance of the brain, expanded metabolic screening, pyruvic acid, lactic acid, and in case of seizures, cytochemical, and culture of cerebrospinal fluid (CSF) and PCR (polymerase chain reaction) for herpes. Results: A total of 98 (2.8%) out of 3,454 newborns were admitted due to episodes of cyanosis. Gestational age: 37.8 + 1.4 weeks, birth weight: 3,145 + 477 g. Maternal age: 32 + 4.8 years. Disease was present in 19.4% of mothers; gestational diabetes (8.1%), pregnancy induced hypertension (5.1%), intrahepatic cholestasis (3.1%), and intrauterine growth retardation (3.1%). Gender: 48.8% male, 51.2% female (NS). Birth: caesarean section, 68.4%, and vaginal delivery, 31.6%. Age on admission 1.9 + 1.4 days. Hospital stay: 4.2 + 4.2 days. First line tests were performed in 100% of patients with 39.8% fulfilling the criteria for second line study. A condition was detected in 21.4%, with convulsive syndrome was the most frequent (33%). Newborns with an identified condition had 3.8 + 2.7episodes versus 1.5 + 2,4 in those without diagnosis (NS). A home oxygen monitor was given to 15.4%. There were no re-admissions. Conclusions: Most newborns admitted due to cyanosis are discharged with a condition of unknown origin. In this study, convulsive syndrome was the most frequent cause.


Subject(s)
Animals , Female , Mice , Drug Carriers/chemistry , Epirubicin/chemistry , Epirubicin/pharmacology , Nanoparticles/chemistry , Neoplasms/drug therapy , Silicon Dioxide/chemistry , Cell Line, Tumor , Drug Delivery Systems/methods , Mice, Inbred BALB C , Particle Size , Polyethylene Glycols/chemistry , Polyethyleneimine/chemistry , Porosity , Tissue Distribution
16.
J. appl. oral sci ; 23(3): 321-328, May-Jun/2015. tab, graf
Article in English | LILACS, BBO | ID: lil-752432

ABSTRACT

The use of nanoparticles (NPs) has become a significant area of research in Dentistry. Objective The aim of this study was to investigate the physical, antibacterial activity and bond strength properties of conventional base, core build and restorative of glass ionomer cement (GIC) compared to GIC supplemented with titanium dioxide (TiO2) nanopowder at 3% and 5% (w/w). Material and Methods Vickers microhardness was estimated with diamond indenter. Compressive and flexural strengths were analyzed in a universal testing machine. Specimens were bonded to enamel and dentine, and tested for shear bond strength in a universal testing machine. Specimens were incubated with S. mutans suspension for evaluating antibacterial activity. Surface analysis of restorative conventional and modified GIC was performed with SEM and EDS. The analyses were carried out with Kolmogorov-Smirnov, ANOVA (post-hoc), Tukey test, Kruskal-Wallis, and Mann Whitney. Results Conventional GIC and GIC modified with TiO2 nanopowder for the base/liner cement and core build showed no differences for mechanical, antibacterial, and shear bond properties (p>0.05). In contrast, the supplementation of TiO2 NPs to restorative GIC significantly improved Vickers microhardness (p<0.05), flexural and compressive strength (p<0.05), and antibacterial activity (p<0.001), without interfering with adhesion to enamel and dentin. Conclusion GIC supplemented with TiO2 NPs (FX-II) is a promising material for restoration because of its potential antibacterial activity and durable restoration to withstand the mastication force. .


Subject(s)
Anti-Bacterial Agents/chemistry , Dental Bonding/methods , Glass Ionomer Cements/chemistry , Nanoparticles/chemistry , Titanium/chemistry , Analysis of Variance , Compressive Strength , Dental Enamel/drug effects , Dentin/drug effects , Hardness Tests , Materials Testing , Microscopy, Electron, Scanning , Pliability , Reference Values , Shear Strength , Statistics, Nonparametric , Streptococcus mutans/drug effects , Surface Properties
17.
Braz. j. pharm. sci ; 51(2): 255-263, Apr.-June 2015. ilus
Article in English | LILACS | ID: lil-755064

ABSTRACT

The use of nanotechnology based on the development and fabrication of nanostructures is one approach that has been employed to overcome the challenges involved with conventional drug delivery systems. Formulating Nanoplex is the new trend in nanotechnology. A nanoplex is a complex formed by a drug nanoparticle with an oppositely charged polyelectrolyte. Both cationic and anionic drugs form complexes with oppositely charged polyelectrolytes. Compared with other nanostructures, the yield of Nanoplex is greater and the complexation efficiency is better. Nanoplex are also easier to prepare. Nanoplex formulation is characterized through the production yield, complexation efficiency, drug loading, particle size and zeta potential using scanning electron microscopy, differential scanning calorimetry, X-ray diffraction and dialysis studies. Nanoplex have wide-ranging applications in different fields such as cancer therapy, gene drug delivery, drug delivery to the brain and protein and peptide drug delivery...


O uso da nanotecnologia baseada no desenvolvimento e na fabricação de nanoestruturas é uma abordagem que tem sido empregada para superar os desafios envolvidos nos sistemas de liberação de fármacos convencionais. A formulação de nanoplexos é a nova tendência na nanotecnologia. Um nanoplexo é um complexo formado pela nanopartícula do fármaco com poplieletrólito de carga oposta. Tanto fármacos catiônicos quanto aniônicos formam complexos com polieletrólitos opostamente carregados. Comparado com outras nanoestruturas, o rendimento dos nanoplexos é maior e a eficiência de complexação é melhor. Nanoplexos são, também. De mais fácil preparação. A formulação de nanoplexo é caracterizada pelo rendimento de produção, eficiência de complexação, carga do fármaco, tamanho de partícula e potencial zeta, utilizando microscopia eletrônica de varredura, calorimetria exploratória diferencial, difração de raios X e estudos de diálise. Os nanoplexos têm aplicações amplas em diferentes campos, como terapia antineoplásica, liberação em terapia gênica, liberação cerebral de fármaco, liberação de fármacos protéicos e peptídicos...


Subject(s)
Humans , Drug Compounding , Nanotechnology , Nanoparticles/chemistry , Chemistry, Pharmaceutical
18.
Acta cir. bras ; 30(4): 255-263, 04/2015. tab, graf
Article in English | LILACS | ID: lil-744282

ABSTRACT

PURPOSE: To evaluate the biocompatibility and osteogenesis of castor oil polymer doped with SiO2 or BaTiO3 nanoparticles. METHODS: Twenty four male rats Wistar were submitted to bone defect filled with castor oil polymer. The animals were distributed in two experimental groups had been formed with 12 animals each: Group 1 - Castor oil polymer doped with 0.30 grams of SiO2 replacing 0.30 grams of CaCO3. Group 2 - Castor oil polymer doped with 0.30 grams of BaTiO3 replacing 0.30 grams of CaCO3. Euthanasia occurred 30 and 60 days after surgery and the femurs were sent to histological analysis and MEV. RESULTS: The implants were biocompatible and allowed for progressive osteogenesis through osteoconduction in both observation periods. There was significant bone neoformation at 30 and 60 days in both groups within the histomorphometric evaluation, but group 1's osteogenesis was lesser in the 30 and 60-day periods observed when compared to the animals of group 2. The MEV morphometric evaluation evidenced a lesser percentage of osseous tissue filling within the BaTiO2-doped polymer. CONCLUSION: The castor oil polymer doped with SiO2 or BaTiO3 remained biocompatible and allowed for progressive osteogenesis in both observation periods. .


Subject(s)
Animals , Male , Barium Compounds/pharmacology , Biocompatible Materials/pharmacology , Biopolymers/pharmacology , Castor Oil/pharmacology , Nanoparticles/chemistry , Osteogenesis/drug effects , Silicon Dioxide/pharmacology , Titanium/pharmacology , Bone Regeneration/drug effects , Femur/drug effects , Femur/pathology , Implants, Experimental , Materials Testing , Microscopy, Electron, Scanning , Osseointegration/drug effects , Random Allocation , Rats, Wistar , Reproducibility of Results , Time Factors
19.
Rev. bras. enferm ; 68(2): 235-243, Mar-Apr/2015.
Article in Portuguese | LILACS, BDENF | ID: lil-752513

ABSTRACT

RESUMO Objetivo: conhecer as condições de trabalho de agentes penitenciários e os reflexos do exercício da atividade laboral em sua saúde. Método: pesquisa descritiva, qualitativa. Os dados foram coletados por meio de entrevista aberta com agentes de um presídio regional e submetidos a análise de conteúdo na modalidade temática. Resultados: os resultados revelaram condições de trabalho insatisfatórias por deficiência de recursos materiais e descaso do poder público com as questões inerentes à ressocialização do apenado, resultando em exposição aos riscos psicossociais, insatisfação e desgaste emocional dos trabalhadores. Conclusão: investimentos na segurança dos trabalhadores podem contribuir para a promoção de sua saúde. .


RESUMEN Objetivo: conocer las condiciones laborales de guardias de prisión y las consecuencias del ejercicio de la actividad laboral en su salud. Método: investigación cualitativa y descriptiva. Los datos fueron recolectados a través de entrevistas abiertas con agentes de una cárcel regional y se sometieron a análisis de contenido en la modalidad temática. Resultados: los resultados mostraron condiciones insatisfactorias por la falta de recursos materiales y el abandono por parte del gobierno en los asuntos relacionados con la rehabilitación del condenado, lo que resulta en la exposición a riesgos psicosociales, la insatisfacción y el agotamiento emocional de los trabajadores. Conclusión: las inversiones en la seguridad de los trabajadores pueden contribuir a la promoción de su salud. .


ABSTRACT Objective: to understand the working conditions of prison offi cers and the repercutions of labor activity on their health. Method: qualitative and descriptive research. Data were collected through open interviews with the prison offi cers of a regional prision and the speeches were submitted to content analysis. Results: the results showed unsatisfactory working conditions due to poor material resources and neglect of governmental regarding rehabilitation of convicts, resulting in workers’ exposure to psychosocial risks, dissatisfaction, and emotional distress. Conclusion: investments on the security of workers may contribute to their health promotion. .


Subject(s)
Calcium Carbonate/chemistry , Nanocomposites/chemistry , Nanoparticles/chemistry , Starch/chemistry , Zea mays/chemistry , Biocompatible Materials , Elastic Modulus , Microscopy, Electron, Scanning , Nanocomposites/ultrastructure , Nanoparticles/ultrastructure , Permeability , Tensile Strength
20.
Braz. dent. j ; 26(1): 50-55, Jan-Feb/2015. tab, graf
Article in English | LILACS | ID: lil-735837

ABSTRACT

Connecting prostheses to the implant abutments has become a concern and achieving a satisfactory retention has been focused in cement-retention prostheses recently. Sandblasting is a method to make a roughened surface for providing more retention. The aim of this study was to compare effects of nano and micro airborne abrasive particles (ABAP) in roughening surface of implant abutments and further retention of cemented copings. Thirty Xive abutments and analogues (4.5 D GH1) were mounted vertically in self-cured acrylic blocks. Full metal Ni-Cr copings with a loop on the top were fabricated with appropriate marginal adaptation for each abutment. All samples were divided into 3 groups: first group (MPS) was sandblasted with 50 µm Al2O3 micro ABAP, second group (NSP) was sandblasted with 80 nm Al2O3 nano ABAP, and the third group (C) was assumed as control. The samples were cemented with provisional cement (Temp Bond) and tensile bond strength of cemented copings was evaluated by a universal testing machine after thermic cycling. The t test for independent samples was used for statistical analysis by SPSS software (version 15) at the significant level of 0.05. Final result showed significant difference among all groups (p<0.001) and MPS manifested the highest mean retention (207.88±45.61 N) with significant difference among other groups (p<0.001). The control group showed the lowest bond strength as predicted (48.95±10.44 N). Using nano or micro ABAP is an efficient way for increasing bond strengths significantly, but it seems that micro ABAP was more effective.


A conexão das próteses nos pilares dos implantes dentários é um fator de preocupação e a obtenção de uma retenção satisfatória tem sido objeto de estudos recentes em próteses com retenção cementária. O jateamento é um método de obter uma superfície áspera para aumentar a retenção. O objetivo do presente estudo foi comparar os efeitos de jateamento com nano- e micropartículas abrasivas para tornar áspera a superfície dos pilares de implantes e a consequente aumentar a retenção dos copings cimentados. Trinta pilares Xive com seus análogos (4.5 D GH1) foram montados na posição vertical em blocos de acrílico auto-polimerizados. Copings metálicos de Ni-Cr com uma alça no topo foram feitos com adaptação marginal apropriada para cada pilar. Todas as amostras foram divididas em três grupos: o 1° grupo (MPS) foi jateado com micropartículas de Al2O3 com 50 µm de tamanho médio; o 2° grupo (NPS) foi jateado com nanopartículas de Al2O3 com 80 nm de tamanho médio; e o 3° grupo (C) foi considerado controle. As amostras foram cimentadas com cimento provisório (Temp Bond) e a resistência à tração dos copings cimentados foi avaliada em máquina universal de ensaios após processo de termociclagem. O teste t para amostras independentes foi usado para fins de análise estatística empregando-se o software SPSS v. 15, com nível de significância de 0,05. Os resultados demonstraram diferença significante entre todos os grupos (p<0,001) e o grupo MPS mostrou o maior valor médio de resistência de união (207,88±45,61 N) com diferenças significantes em relação aos outros grupos (p<0,001). Conforme previsto, o grupo controle obteve o menor valor de resistência (48,95±10,44 N). O jateamento com micro ou nano partículas mostrou-se um modo eficaz de aumentar significativamente a resistência de união, mas aparentemente as micropartículas são mais eficazes.


Subject(s)
Animals , Air Abrasion, Dental , Dental Abutments , Dental Bonding/methods , Dental Cements/chemistry , Dental Implants , Dental Prosthesis Retention , Dental Materials/chemistry , Dental Stress Analysis , Microscopy, Electron, Scanning , Nanoparticles/chemistry , Particle Size , Surface Properties , Tensile Strength
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