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1.
Odovtos (En línea) ; 25(3): 67-81, Sep.-Dec. 2023. graf
Article in English | LILACS, SaludCR | ID: biblio-1529070

ABSTRACT

Abstract To compare the physicochemical composition of 4 MTAs commercially available in Latin America. ProRoot MTA (Dentsply, USA), MTA Angelus (Angelus, Brazil), MTA Flow (Ultradent, USA), and MTA Viarden (Viarden, Mexico) were physically and chemically compared. Scanning electron microscopy (SEM) images were obtained from the MTA powder and the prepared presentations. Energy Dispersive X-Ray Spectroscopy (EDS) analyses were performed by triplicate, to calculate the mass proportion of calcium (Ca), silicon (Si), the Ca/Si proportion among the 4 brands. Thermogravimetric analyses (TGA) were conducted (50ºC-1000ºC), and mass loss and inflection points were calculated for each material. Statistical differences for Ca and Si content were determined by ANOVA (p<0.05). SEM images showed evident differences in the appearance of both the powder and the prepared MTAs among brands. Angelus MTA showed cubic prisms not observed in the other 3 brands. ProRoot MTA and MTA Flow showed similar homogeneous structures. MTA Viarden was the less homogeneous, with random structures (>15um). When comparing the mass proportions of Ca and Si between the 4 powder samples, MTA Viarden showed a significantly lower proportions of both elements when compared with the other brands (p<0.005). TGA análisis showed a similar behavior for ProRoot MTA, MTA Angelus and MTA Flow, with less than 2% mass loss when the 1000C temperature was reached. MTA Viarden showed a mass loss of 9,94% before the 700C, indicating the presence of different content sensible to temperature degradation. The analyzed MTAs demonstrated to vary significantly in their chemical composition and physical characteristics. Clinicians must be aware of the differences between different brands of a same material, and future research should focus on the clinical implications of these differences.


Resumen Comparar la composición fisicoquímica de 4 MTA disponibles comercialmente en América Latina. Se compararon física y químicamente ProRoot MTA (Dentsply, EE. UU.), MTA Angelus (Angelus, Brasil), MTA Flow (Ultradent, EE. UU.) y MTA Viarden (Viarden, México). Se obtuvieron imágenes de microscopía electrónica de barrido (SEM) del polvo de MTA y de las presentaciones preparadas. Los análisis de espectroscopía de dispersión de energía de rayos X (EDS) se realizaron por triplicado para calcular la proporción de masa de calcio (Ca), silicio (Si), la proporción Ca/Si entre las 4 marcas. Se realizaron análisis termogravimétricos (TGA) (50ºC-1000ºC), y se calcularon las pérdidas de masa y los puntos de inflexión para cada material. Las diferencias estadísticas para el contenido de Ca y Si se determinaron mediante ANOVA (p<0,05). Los análisis SEM mostraron diferencias evidentes en la apariencia tanto del polvo como las preparaciones de los MTA, entre las diferentes marcas. MTA Angelus mostró prismas cúbicos no observados en las otras 3 marcas. ProRoot MTA y MTA Flow mostraron estructuras homogéneas similares. MTA Viarden fue el menos homogéneo, con estructuras aleatorias (>15um). Al comparar las proporciones de masa de Ca y Si entre las 4 muestras de polvo, MTA Viarden mostró proporciones significativamente más bajas de ambos elementos en comparación con las otras marcas (p<0,005). El análisis TGA mostró un comportamiento similar para ProRoot MTA, MTA Angelus y MTA Flow, con menos del 2 % de pérdida de masa al alcanzar los 1000 °C de temperatura. El MTA Viarden mostró una pérdida de masa de 9,94% antes de los 700 °C, indicando la presencia de diferentes contenidos sensibles a la degradación por temperatura. Los MTA analizados demostraron diferencias significativas en su composición química y características físicas. Los clínicos deben ser conscientes de las diferencias entre las diferentes marcas de un mismo material, y futuras investigaciones deben enfocarse en las implicaciones clínicas de estas diferencias.


Subject(s)
Microscopy, Electron, Scanning , Ceramics/analysis , Endodontics , Biocompatible Materials
2.
Int. j. morphol ; 41(4): 1219-1227, ago. 2023. ilus
Article in English | LILACS | ID: biblio-1514335

ABSTRACT

SUMMARY: In this study we describe the functional morphology of Cornu aspersum (Helix aspersa), spermatozoa using light, scanning (SEM) and transmission electron (TEM) microscopies. The studies were performed with sperm located in the frozen hermaphroditic duct. Our results showed that the head presents an elongated conical shape slightly coiled in a corkscrew, with the nucleus partially covered by an acrosome, where an apical vesicle is located at the lateralized apex. This peculiar shape suggests the helical displacement movement of the spermatozoa. The head and the nucleus are slightly larger size compared to those of other gastropod species. The intermediate tract is surrounded by a mitochondrial complex and a glycogen helix. The glycogen helix is coiled helically along the intermediate tract, presenting at least five twists of glycogen helices. The complexity of both the mitochondrial complex and the glycogen helix suggests a high metabolic consumption considering the long period of time until fertilization occurs. Our findings on the detailed characterization of Cornu aspersum spermatozoa, obtained from a frozen hermaphroditic duct can contribute to a better understanding of the functional morphology of sperm and serve as a reference for future studies.


En este estudio describimos la morfología funcional de Cornu aspersum (Helix aspersa), espermatozoides utilizando microscopías de luz, barrido (SEM) y electrónica de transmisión (TEM). Los estudios se realizaron con espermatozoides localizados en el conducto hermafrodita congelado. Nuestros resultados mostraron que la cabeza presenta una forma cónica alargada ligeramente enrollada en un tirabuzón, con el núcleo parcialmente cubierto por un acrosoma, donde se ubica una vesícula apical en el ápice lateralizado. Esta peculiar forma sugiere el movimiento de desplazamiento helicoidal de los espermatozoides. La cabeza y el núcleo son de un tamaño ligeramente mayor en comparación con los de otras especies de gasterópodos. El tracto intermedio está rodeado por un complejo mitocondrial y una hélice de glucógeno. La hélice de glucógeno se enrolla helicoidalmente a lo largo del tracto intermedio, presentando al menos cinco giros de hélices de glucógeno. La complejidad tanto del complejo mitocondrial como de la hélice de glucógeno sugiere un alto consumo metabólico considerando el largo período de tiempo hasta que ocurre la fecundación. Nuestros hallazgos sobre la caracterización detallada de los espermatozoides de Cornu aspersum, obtenidos de un conducto hermafrodita congelado, pueden contribuir a una mejor comprensión de la morfología funcional de los espermatozoides y servir como referencia para futuros estudios.


Subject(s)
Animals , Snails , Spermatozoa/ultrastructure , Spermatozoa/physiology , Microscopy, Electron, Scanning , Cryopreservation , Microscopy, Electron, Transmission , Hermaphroditic Organisms
3.
Int. j. morphol ; 41(4): 1058-1065, ago. 2023. ilus
Article in English | LILACS | ID: biblio-1514349

ABSTRACT

SUMMARY: The existence of "transitional muscular structures" between subendocardial branches (Purkinje fibers) and ventricular working muscle fibers (WF) was first described by the German anatomist, Kurt Goerttler, in 1964. He designated them as "subendocardial nucleus organs." He supposed such fibers functioned as mechanoreceptors, controlling of the intensity of contraction of the ventricular musculature. Brazilian anatomist Ferraz de Carvalho described similar structures in 1993. A thorough literature search failed to identify any other research articles confirming or denying their existence. The objective of this work was to find such structures in subendocardial ventricular walls in human hearts. We collected fifteen formalin-preserved hearts from the Anatomy Department of São Paulo University and sectioned the apical portions on the right and left ventricles according to method used by Goerttler. We utilized conventional histology (light microscopy- LM), scanning electron microscopy (SEM), and a new preservation method called micro- plastination (MP). At the anterior wall of the right ventricle in the subendocardial region between the interventricular septum and moderator band, we found several bundles of fusiform and helicoidal fibers of similar histology to the WF. The bundles measured between 400 and 1150 µm in length and were separated from adjacent muscular fibers by thin collagen fiber, thus acting as a "pseudo capsule." Some structures seemed to be linked to PF and were appeared to be lymphatic and blood vessels and nerves. We called those structures "cardiac corpuscles" (CC). The observation of the previously "unknown" CC in this initial study confirmed the previous descriptions and its discovery may contribute to new perspectives in the study of cardiac muscle structure and function.


La existencia de "estructuras musculares de transición" entre los ramos subendocárdicos (fibras de Purkinje) y las fibras musculares ventriculares activas(FMV) fue descrita por primera vez por el anatomista alemán Kurt Goerttler en 1964, quien las denominó "órganos del núcleo subendocárdico". Supuso que tales fibras funcionaban como mecanoreceptores, controlando la intensidad de la contracción de la musculatura ventricular. El anatomista brasileño Ferraz de Carvalho describió estructuras similares en 1993. Una búsqueda bibliográfica exhaustiva no logró identificar ningún otro artículo de investigación que confirmara o negara su existencia. El objetivo de este trabajo fue encontrar dichas estructuras en las paredes ventriculares subendocárdicas de corazones humanos. Recolectamos 15 corazones conservados en formalina del Departamento de Anatomía de la Universidad de São Paulo y seccionamos las porciones apicales de los ventrículos derecho e izquierdo según el método utilizado por Goerttler. Utilizamos histología convencional (microscopía de luz-LM), microscopía electrónica de barrido (SEM) y un nuevo método de conservación llamado microplastinación (MP). En la pared anterior del ventrículo derecho en la región subendocárdica entre el tabique interventricular y la banda moderadora, encontramos varios haces de fibras fusiformes y helicoidales de histología similar a la FMV. Los haces medían entre 400 y 1150 µm de longitud y estaban separados de las fibras musculares adyacentes por una fina fibra de colágeno, actuando así como una "pseudocápsula". Algunas estructuras parecían estar vinculadas a la fibras de purkinje y parecían ser vasos linfáticos, sanguíneos y nerviosos. Llamamos a esas estructuras "corpúsculos cardíacos" (CC). La observación del CC previamente "desconocido" en este estudio inicial confirmó las descripciones anteriores y su descubrimiento puede contribuir a nuevas perspectivas en el estudio de la estructura y función del músculo cardíaco.


Subject(s)
Humans , Purkinje Fibers/anatomy & histology , Heart/anatomy & histology , Heart Ventricles/anatomy & histology , Microscopy, Electron, Scanning
4.
Odovtos (En linea) ; 25(1)abr. 2023.
Article in English | LILACS, SaludCR | ID: biblio-1422197

ABSTRACT

This study evaluated selected structural and physical properties, such as degree of conversion (DC), Vickers hardness (VHN), and compression strength (CS), of three new dual-cure bulk-fill resin-based composites (RBCs; ACTIVA, HyperFIL, and Fill-Up) and compared them to those of a conventional RBC (Filtek Z250) at three clinically relevant depths. Samples (n=180) were prepared in three depths (2,4, and 6mm). Fourier-transform infrared spectroscopy (FTIR) analysis and VHN and CS tests were performed. The DC value was calculated by considering the relative change in the aliphatic C=C peaks. The fractured surfaces of representative samples were characterized using scanning electron microscopy (SEM). Data were statistically evaluated using two-way analysis of variance and post hoc Bonferroni tests (p<0.05). According to the VHN results, Filtek Z250 showed the highest bottom/top hardness ratio (97.94±1.01) at 2mm thickness and ACTIVA showed the lowest bottom/top hardness ratio (43.48±5.64) at 6mm thickness (p<0.001). According to the FTIR results, the DC decreased with increasing thickness in all materials (p<0.05). Filtek Z250 showed the highest (301±12.4 MPa) and ACTIVA exhibited the lowest (232±17.2 MPa) CS values at 2mm thickness (p<0.05). The lowest CS values were obtained for ACTIVA, and the highest values were obtained for Filtek Z250 for samples with thicknesses of 4 and 6mm, respectively (p<0.05). The structural features of restorative composites, such as the resin chemistry and filler type and content, and the operational parameters (i.e., material thickness and curing conditions) strongly affect crosslinking reactions and thus the DC, VHN, and CS values.


Este estudio evaluó propiedades físicas y estructurales, como el grado de conversión (DC), la dureza Vickers (VHN) y la resistencia a la compresión (CS), de tres nuevos compósitos a base de resina de curado dual tipo bulk (RBC; ACTIVA , HyperFIL y Fill-Up) y los comparó con los de una resina compuesta convencional (Filtek Z250) en tres profundidades clínicamente relevantes. Se prepararon muestras (n=180) en tres profundidades (2,4 y 6mm). Se realizaron análisis de espectroscopia infrarroja por transformada de Fourier (FTIR) y pruebas VHN y CS. El valor de DC se calculó considerando el cambio relativo en los picos alifáticos C=C. Las superficies fracturadas de muestras representativas se caracterizaron mediante microscopía electrónica de barrido (MEB). Los datos se evaluaron estadísticamente mediante análisis de varianza de dos vías y pruebas post hoc de Bonferroni (p<0,05). De acuerdo con los resultados de VHN, Filtek Z250 mostró la relación de dureza inferior/superior más alta (97,94±1,01) con un espesor de 2mm y ACTIVA mostró la relación de dureza inferior/superior más baja (43,48±5,64) con un espesor de 6mm (p<0,001). De acuerdo con los resultados de FTIR, la DC disminuyó al aumentar el espesor en todos los materiales (p<0,05). Filtek Z250 mostró los valores de CS más altos (301±12,4 MPa) y ACTIVA los más bajos (232±17,2 MPa) a 2mm de espesor (p<0,05). Los valores más bajos de CS se obtuvieron para ACTIVA y los valores más altos para Filtek Z250 para muestras con espesores de 4 y 6mm, respectivamente (p<0,05). Las características estructurales de las resinas compuestas de restauración, como la química; además del tipo y contenido del relleno, y los parámetros operativos (es decir, el espesor del material y las condiciones de curado) afectan en gran medida las reacciones de interacción química y, por lo tanto, los valores de DC, VHN y CS.


Subject(s)
Microscopy, Electron, Scanning , Composite Resins/analysis , Compressive Strength
5.
Int. j. morphol ; 41(1): 65-72, feb. 2023. ilus
Article in English | LILACS | ID: biblio-1430530

ABSTRACT

SUMMARY: Respiration and water-liquid transportation are controlled by many factors in the lung. The aim of this study was to explore the structure and proteins expression in lungs of Phrynocephalus vlangalii by means of gross anatomy, light microscope observation, scanning electron microscope and immunohistochemistry. Results show that there were many alveoli in the lung and the walls of alveoli and capillaries were very thin. The inner surface of the lung was divided into many cystic chambers by reticular diaphragm, and the network of pulmonary capillaries was dense. Immunohistochemistry showed that AQP1 was mainly expressed in the epithelium of interstitial bronchi, parabronchiole endothelium, capillary endothelium and alveolar epithelial cells. VIP positive nerve fibers are mainly distributed in trachea, bronchial smooth muscle layer, the walls of pulmonary vessels and bronchial vessels and around submucosal glands. CECR2 is distributed in peripheral capillaries and small. Investigations of structure and proteins biology could be relevant with the adaptive strategy to drought and hypoxia environment in Phrynocephalus vlangalii.


La respiración y el transporte de agua y líquido están controlados en el pulmón por muchos factores. El objetivo de este estudio fue explorar la estructura y la expresión de proteínas en los pulmones de Phrynocephalus vlangalii por medio de la anatomía macroscópica, observación con microscopio óptico, microscopio electrónico de barrido e inmunohistoquímica. Los resultados muestran que había muchos alvéolos en el pulmón y que las paredes de los alvéolos y de los capilares eran muy delgadas. La superficie interna del pulmón estaba dividida en cámaras quísticas por el diafragma reticular y se observó una densa red de capilares pulmonares. La inmunohistoquímica mostró que AQP1 se expresaba principalmente en el epitelio de los bronquios intersticiales, el endotelio parabronquial, el endotelio capilar y las células epiteliales alveolares. Las fibras nerviosas VIP positivas se distribuyen principalmente en la tráquea, la capa de músculo liso bronquial, las paredes de los vasos pulmonares y los vasos bronquiales y alrededor de las glándulas submucosas. CECR2 se distribuye en pequeño capilares periféricos. Las investigaciones de la biología de la estructura y las proteínas podrían ser relevantes con la estrategia de adaptación al entorno de sequía e hipoxia en Phrynocephalus vlangalii.


Subject(s)
Animals , Adaptation, Physiological , Lizards/anatomy & histology , Lung/anatomy & histology , Immunohistochemistry , Microscopy, Electron, Scanning , Lung/ultrastructure
6.
Int. j. morphol ; 41(1): 195-209, feb. 2023. ilus
Article in English | LILACS | ID: biblio-1430542

ABSTRACT

SUMMARY: The aim of the present in vitro study is to visualize dentin to get an in-depth knowledge of the nature of dentin that could provide useful information regarding conditioning dentinal substrate when treating dentinal lesions. Forty-nine extracted human third molars were obtained and prepared to produce artificial dentinal lesions through demineralizing with acetic acid for 7 and 14 days, or lactic acid for 7 days. The teeth were divided into groups and treated with either NaOCl, pepsin, trypsin, or phosphoric acid. To obtain information on the morphology of the treated dentinal surfaces, all samples were visualized under high resolution field emission scanning electron microscope. With high magnification reaching x50000 dentin was clearly visualized together with its constitutes. The effect of various demineralization approaches and various treatment protocols were demonstrated clearly. The relationship between the conditioning procedure steps and the subsequent bond strength was discussed. To our best knowledge, there is no previous clear highly magnified scanning electron microscope images for dentin, and dentinal components and constitutes with and without various treatments. The current in vitro study suggests the complexity nature of dentin as a substrate that should be treated carefully especially with technique sensitive procedures such as adhesive restorations.


El objetivo del presente estudio in vitro fue visualizar la dentina para obtener un conocimiento completo de la naturaleza de ella lo que podría proporcionar información útil sobre el acondicionamiento del sustrato dentinario en el tratamiento de lesiones dentinarias. Se obtuvieron 49 terceros molares humanos extraídos y se prepararon para producir lesiones dentinales artificiales mediante desmineralización con ácido acético por 7 y 14 días, o ácido láctico por 7 días. Los dientes se dividieron en grupos y se trataron con NaOCl, pepsina, tripsina o ácido fosfórico. Para obtener información sobre la morfología de las superficies dentinarias tratadas, todas las muestras se visualizaron bajo un microscopio electrónico de barrido de emisión de campo de alta resolución. Con un gran aumento que alcanzó x50000, la dentina se visualizó claramente junto con sus componentes. Se demostró el efecto de varios enfoques de desmineralización y varios protocolos de tratamiento. Se discutió la relación entre los pasos del procedimiento de acondicionamiento y la subsiguiente fuerza de unión. Hasta donde sabemos, no hay imágenes claras previas de microscopio electrónico de barrido altamente ampliadas para la dentina y los componentes y constituyentes de la dentina con y sin diferentes tratamientos. El estudio in vitro actual sugiere la naturaleza compleja de la dentina como sustrato que debe tratarse con cuidado, especialmente en los procedimientos sensibles a la técnica, tal como las restauraciones adhesivas.


Subject(s)
Humans , Tooth Demineralization/chemically induced , Dentin/drug effects , Dentin/ultrastructure , Sodium Hypochlorite , Microscopy, Electron, Scanning , Trypsin , Pepsin A , Acetic Acid/pharmacology , Lactic Acid/pharmacology
7.
West China Journal of Stomatology ; (6): 276-283, 2023.
Article in English | WPRIM | ID: wpr-981124

ABSTRACT

OBJECTIVES@#The current study aimed to investigate the bonding properties of a novel low-shrinkage resin adhesive containing expanding monomer and epoxy resin monomer after thermal cycling aging treatment.@*METHODS@#Expanding monomer of 3,9-diethyl-3,9-dimethylol-1,5,7,11-tetraoxaspiro-[5,5] undecane (DDTU) as an anti-shrinkage additive and unsaturated epoxy monomer of diallyl bisphenol A diglycidyl ether (DBDE) as a coupling agent were synthesized. A blend of DDTU and DBDE at a mass ratio of 1∶1, referred to as "UE", was added into the resin matrix at the mass fraction of 20% to prepare a novel low-shrinkage resin adhesive.Then, the methacrylate resin adhesive without UE was used as the blank control group, and a commercial resin adhesive system was selected as the commercial control group. Moreover, the resin-dentin bonding and micro-leakage testing specimens were prepared for the thermal cycling aging treatment. The bonding strength was tested, the fracture modes were calculated, the bonding fracture surface was observed by scanning electron microscope (SEM), and the dye penetration was used to evaluate the tooth-restoration marginal interface micro-leakage. All the data were analyzed statistically.@*RESULTS@#After aging, the dentin bonding strength of the experimental group was (19.20±1.03) MPa without a significant decrease (P>0.05), that of the blank control group was (11.22±1.48) MPa with a significant decrease (P<0.05) and that of the commercial control group was (19.16±1.68) MPa without a significant decrease (P>0.05). The interface fracture was observed as the main fracture mode in each group after thermal cycling by SEM. The fractured bonding surfaces of the experimental group often occurred on the top of the hybrid layer, whereas those of the blank and commercial control groups mostly occurred on the bottom of the hybrid layer. Micro-leakage rating counts of specimens before and after thermal cycling were as follows: the experimental group was primarily 0 grade, thereby indicating that a relatively ideal marginal sealing effect could be achieved (P>0.05); meanwhile, the blank control group was primarily 1 grade, and the penetration depth of dye significantly increased after thermal cycling (P<0.05); the commercial control group was primarily 0 grade without statistical difference before and after thermal cycling (P>0.05), while a significant difference was observed between the commercial control group and experimental group after thermal cycling (P<0.05).@*CONCLUSIONS@#The novel low-shrinkage resin adhesive containing 20%UE exhibited excellent bonding properties even after thermal cycling aging treatment, thereby showing a promising prospect for dental application.


Subject(s)
Composite Resins , Dental Bonding , Dental Cements , Surface Properties , Resin Cements , Dentin-Bonding Agents , Dentin , Materials Testing , Microscopy, Electron, Scanning
8.
Braz. J. Pharm. Sci. (Online) ; 59: e22430, 2023. tab, graf
Article in English | LILACS | ID: biblio-1439530

ABSTRACT

Abstract Lipoprotein monitoring is desirable in the management of medical conditions such as atherosclerotic cardiovascular disease and coronary artery disease, in which controlling the concentration of these chylomicrons is crucial. Current clinical methods are complex and present poor reproducibility between laboratories. For these reasons, recent guidelines discard the assessment of low-density lipoprotein cholesterol (LDL-C) as a routine analysis during lipid-lowering therapies. Concerning the importance of monitoring this parameter, the authors present an electrochemical immunosensor constructed from a simple and easy-to-reproduce platform that allows detecting and quantifying LDL nanoparticles directly from human serum samples. The performance of the biosensor was studied by scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The biosensing platform displays good stability and linearity between 30 mg dL-1 and 135 mg dL-1 with a detection limit of 20 mg dL-1. The proposed biosensor can be easily employed for monitoring LDL concentration in clinical treatments.


Subject(s)
Phase Transition , Lipoproteins, LDL/analysis , Microscopy, Electron, Scanning/methods , Electrochemistry/instrumentation , Dielectric Spectroscopy/methods , Hypercholesterolemia/classification
9.
Braz. J. Pharm. Sci. (Online) ; 59: e21265, 2023. tab, graf
Article in English | LILACS | ID: biblio-1439543

ABSTRACT

Abstract Piper nigrum (black pepper) is used in Indian traditional medicine and its main alkaloid, Piperine (PIP), presents antioxidant, antitumor and neuroprotective pharmacological properties. This substance is insoluble in aqueous media and can irritate the gastrointestinal tract. Aiming to avoid these inconvenient characteristics and enable PIP oral administration, this study suggested the PIP microencapsulation through the emulsion-solvent evaporation method and the preparation of microparticulated tablets by direct compression. An UV-spectroscopy method was validated to quantify PIP. Microparticles and microparticulated tablets were successfully obtained and the microparticles exhibited excellent flow. The scanning electron microscopy images showed that PIP microparticles were intact after compression. The in vitro release showed a controlled release of PIP from microparticles and PIP microparticles from tablets in comparison to PIP and PIP tablets. The release profiles of PIP microparticles and the microparticulated tablets were similar. Therefore, tablets containing PIP microparticles are promising multiparticulated dosage forms because a tablet allows microparticles administration and the intact ones promote a controlled release, decreasing its irritating potential on the mucosa.


Subject(s)
Spectrum Analysis/methods , Microscopy, Electron, Scanning/methods , Piper nigrum/adverse effects , Gastrointestinal Tract/abnormalities , Drug Compounding/instrumentation , Tablets/classification , In Vitro Techniques/methods , Alkaloids/adverse effects , Medicine, Traditional/instrumentation , Antioxidants/adverse effects
10.
Braz. dent. sci ; 26(2): 1-8, 2023. ilus, tab
Article in English | LILACS, BBO | ID: biblio-1426430

ABSTRACT

Objective: in this study, biofilm formation by Candida albicans in fixed orthodontic appliances was evaluated. Material and Methods: a total of 300 conventional metal brackets (MC), ceramic (CB), self-ligation (SLB), nickel-titanium (NiTi), and nickel-chromium (NiCr) wires, and ligatures types were organized into thirty groups (n=10). To induce biofilm formation, brackets, wires, and ligatures were joined, sterilized, placed in 24-well plates, contaminated with standardized suspensions of C. albicans (107 cells/mL), and incubated at 37 °C for 48 h with shaking. The biofilms formed were detached using an ultrasonic homogenizer, and suspensions were serially diluted and plated on Sabouraud dextrose agar to determine colony-forming units per mL. Scanning electron microscopy was performed before and after the biofilm formation. Results: lower amount of biofilm formation was observed in the MC group than in the CB and SLB groups (p<0.0001). SLB and CB showed similar biofilm formation rates (p=0.855). In general, the cross-sectional wires .018"x.025" showed higher biofilm formation when associated with the three types of brackets. When brackets, wires, and ligatures were associated, the sets with NiCr wires and SSL ligatures with MC brackets (p=0.0008) and CB (p=0.0003) showed higher biofilm formation. Conclusion: thus, brackets of MC with NiTi and NiCr wires showed lower biofilm formation, regardless of the ligature and cross-sectional or gauge of the wire and, MC and CB brackets with NiCr wires and SSL ligatures were more likely to accumulate biofilms (AU)


Objetivo: neste estudo, a formação de biofilme por Candida albicans em aparelhos ortodônticos fixos foi avaliada. Material e Métodos: um total de 300 bráquetes metálicos convencionais (MC), cerâmicos (CB), autoligados (SLB), com fios de níquel-titânio (NiTi) e níquel-cromo (NiCr) e tipos de ligaduras foram organizados em trinta grupos (n=10). Bráquetes, fios e ligaduras foram unidos, esterilizados, colocados em placas de 24 poços, contaminados com suspensões padronizadas de C. albicans (107 células/mL) e incubados a 37°C por 48 h para a formação de biofilmes. Os biofilmes formados foram rompidos por meio de um homogeneizador ultrassônico e suspensões foram diluídas e semeadas em ágar Sabouraud-dextrose para determinar as unidades formadoras de colônias por mL. A microscopia eletrônica de varredura foi realizada antes e após a formação do biofilme. Resultados: foi observada menor formação de biofilme no grupo MC em comparação aos grupos CB e SLB (p<0,0001). A formação de biofilme foi semelhante nos grupos SLB e CB (p=0,855). Em geral, os fios de seção transversal .018"x.025" apresentaram maior formação de biofilme quando associados aos três tipos de bráquetes. Os conjuntos com fios de NiCr e ligaduras SSL com bráquetes MC (p=0,0008) e CB (p=0,0003) apresentaram maior formação de biofilme. Conclusão: bráquetes MC com fios de NiTi e NiCr apresentaram menor formação de biofilme, independente da ligadura e secção transversal ou bitola do fio e, braquetes MC e CB com fios de NiCr e ligaduras SSL foram mais propensos a acumular biofilmes.(AU)


Subject(s)
Candida albicans , Microscopy, Electron, Scanning , Orthodontic Brackets , Biofilms , Orthodontic Appliances, Fixed
11.
Braz. J. Pharm. Sci. (Online) ; 59: e21217, 2023. tab, graf
Article in English | LILACS | ID: biblio-1429971

ABSTRACT

Abstract Solid dispersions (SDs) of ursolic acid (UA) were developed using polyvinylpyrrolidone K30 (PVP K30) in combination with non-ionic surfactants, such as D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) or poloxamer 407 (P407) with the aim of enhancing solubility and in vitro release of the UA. SDs were investigated using a 24 full factorial design, subsequently the selected formulations were characterized for water solubility, X-ray diffractometry (XRD), differential scanning calorimetry (DSC), particle diameter, scanning electron microscopy, drug content, physical-chemical stability and in vitro release profile. SDs showed higher UA water-solubility than physical mixtures (PMs), which was attributed by transition of the drug from crystalline to amorphous or molecular state in the SDs, as indicated by XRD and DSC analyses. SD1 (with P407) and SD2 (with TPGS) were chosen for further investigation because they had higher drug load. SD1 proved to be more stable than SD2, revealing that P407 contributed to ensure the stability of the UA. Furthermore, SD1 and SD2 increased UA release by diffusion and swelling-controlled transport, following the Weibull model. Thus, solid dispersions obtained with PVP k-30 and P407 proved to be advantageous to enhance aqueous solubility and stability of UA.


Subject(s)
Polyethylene Glycols/administration & dosage , Solubility , Poloxamer/adverse effects , Diffusion , X-Rays/adverse effects , In Vitro Techniques , Calorimetry, Differential Scanning/methods , Pharmaceutical Preparations/analysis , Microscopy, Electron, Scanning/methods
12.
Rev. odontol. UNESP (Online) ; 52: e20220054, 2023. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1442090

ABSTRACT

Introduction: fluoride toothpaste is widely used by the population. Objective: dentifrices with a high concentration of sodium fluoride and the presence of tricalcium phosphate were developed, providing additional protection to patients vulnerable to the development of caries. This study aimed to evaluate the influence of different dentifrices on the surface and internal hardness and enamel wear after artificial caries, pH cycling, and toothbrushing. Material and method: enamel blocks (4x4 mm) were obtained from 20 bovine teeth. The specimens were submitted to artificial caries lesion and then to pH cycling and brushing according to the dentifrice: Colgate Total 12 and Clinpro + Tricalcium Phosphate. Result: after this period, they were submitted to analysis of superficial and internal hardness and profilometry. Scanning Electron Microscopy (SEM) was performed. The data obtained were evaluated by one-way Analysis of Variance (ANOVA) to evaluate the mineral recovery and profilometry, and two-way repeated measures ANOVA to evaluate the superficial and internal hardness. Conclusion: analyzing the surface hardness, after caries induction, there was a significant reduction in hardness that was partially recovered regardless of the dentifrice used. For internal hardness, Clinpro obtained lower values on the control side and up to 90 micrometers on the test side. As for profilometry, Colgate Total 12 showed greater wear when compared to Clinpro. It was concluded that Clinpro promoted lower internal hardness, however, Colgate Total 12 resulted in greater surface wear of tooth enamel.


Introdução: dentifrícios fluoretados são amplamente utilizados pela população. Foram desenvolvidos dentifrícios com alta concentração de fluoreto de sódio e presença de tricálcio fosfato, fornecendo proteção adicional a pacientes vulneráveis ao desenvolvimento da cárie. Objetivo: o objetivo deste estudo foi avaliar a influência de diferentes dentifrícios na dureza superficial, interna e desgaste do esmalte após cárie artificial, ciclagem de pH e escovação. Material e método: blocos de esmalte (4x4 mm) foram obtidos a partir de 20 dentes bovinos. Os espécimes foram submetidos à lesão de cárie artificial e, em seguida, à ciclagem de pH e escovação de acordo com o dentifrício: Colgate Total 12 e Clinpro + Tricálcio Fosfato. Após este período, foram submetidos à análise de dureza superficial e interna e perfilometria. Foi realizada microscopia eletrônica de varredura. Resultado: os dados obtidos foram avaliados por ANOVA um critério para avaliar a recuperação mineral e perfilometria, ANOVA dois critérios medidas repetidas para avaliar a dureza superficial e interna. Conclusão: analisando a dureza superficial, após a indução da cárie houve uma redução significativa na dureza que foi parcialmente recuperada independente do dentifrício utilizado. Para dureza interna, Clinpro obteve valores menores no lado controle e até 90 micrômetros no lado teste. Quanto à perfilometria, o Colgate Total 12 apresentou maior desgaste quando comparado ao Clinpro. Concluiu-se que Clinpro promoveu menor dureza interna, porém, o Colgate Total 12 resultou em maior desgaste superficial do esmalte dentário.


Subject(s)
Animals , Cattle , Tooth Remineralization , Toothpastes , Microscopy, Electron, Scanning , Analysis of Variance , Dental Enamel , Fluorine , Dental Caries , Dentifrices
13.
Braz. dent. sci ; 26(3): 1-13, 2023. ilus, tab
Article in English | LILACS, BBO | ID: biblio-1444656

ABSTRACT

Objective: this double-blind randomized clinical trial evaluate the clinical performance of Thermo-Viscous Bulk Fill composite, Self-Adhesive Flowable composite, and Filtek Bulk Fill Composites restorations in Class I cavities over a period of 18 months. Material and Methods: twenty individuals between the ages of 30 and 45 participated in this research. Each patient should have at least three occlusal Class I carious lesions on their molars. They were dispersed at random, with n=20 teeth representing each tested material. Group I (Futurabond M+ and VisCalor Bulk Fill which heated in a viscolar dispenser at 68 °C for 30s and placed in a 4 mm thickness), Group II (Fusio Liquid Dentin self-adhesive composite which put in a thin layer (1mm increment)), and Group III (Single Bond Universal and Filtek Bulk Fill Posterior composite which applied in 4 mm thickness without heating). Using (USPHS) criteria, all restorations were assessed clinically at baseline, 6 months, 12 months, and 18 months. Using an inverse replica, the marginal seal of the investigated restorations was further evaluated under SEM. Statistical analysis was performed with Chi-square test for all USPH parameters. Results: the three tested groups recorded a one hundred percent retention rate after 18 months follow up period. Concerning marginal adaptation, marginal discoloration, anatomical form, surface texture, and color matching, there was a significant difference (p˂0.05) between the three tested groups after 12 & 18 months. After 12 & 18 months, SEM analysis of the marginal seal revealed a statistically significant difference between the three groups. Conclusion: Bulk fill resin composite restorations showed satisfactory acceptable clinical performance after 18 months of clinical service compared to self-adhesive flowable composites, and Viscalor Bulk Fill composite demonstrated excellent results with considerable changes in marginal integrity as a consequence of thermal viscous technology and increased adaptability of restorations toward cavity walls and margins (AU)


Objetivo: este ensaio clínico randomizado duplo-cego avaliou o desempenho clínico de restaurações de resina Bulk Fill Termo-Viscosa, resina autoadesiva Flowable e Filtek Bulk Fill Composites em cavidades Classe I durante um período de 18 meses. Material e Métodos: 20 indivíduos com idade entre 30 e 45 anos participaram da pesquisa. Cada paciente deveria ter pelo menos três lesões de cárie oclusais de Classe I nos molares. Eles foram divididos aleatoriamente, com n=20 dentes representando cada material testado. Grupo I (Futurabond M+ e VisCalor Bulk Fill aquecido em dispensador viscolar a 68 °C por 30s e colocado em uma espessura de 4 mm), Grupo II (resina composta autoadesiva Fusio Liquid Dentin colocada em uma camada fina (incremento de 1 mm)) e Grupo III (resina composta Single Bond Universal e Filtek Bulk Fill Posterior aplicado em espessura de 4 mm sem aquecimento). Usando os critérios (USPHS), todas as restaurações foram avaliadas clinicamente no início, 6 meses, 12 meses e 18 meses. Usando uma réplica inversa, o selamento marginal das restaurações investigadas foi avaliado em MEV. A análise estatística foi realizada com o teste qui-quadrado para todos os parâmetros USPH. Resultados: os três grupos testados registraram uma taxa de retenção de cem por cento após um período de acompanhamento de 18 meses. Em relação à adaptação marginal, descoloração marginal, forma anatômica, textura da superfície e combinação de cores, houve uma diferença significativa (p˂0,05) entre os três grupos testados após 12 e 18 meses. Após 12 e 18 meses, a análise SEM do selamento marginal revelou uma diferença estatisticamente significativa entre os três grupos. Conclusão: as restaurações de resina composta Bulk Fill apresentaram desempenho clínico aceitável satisfatório após 18 meses de atendimento clínico em comparação com as resinas compostas fluidas autoadesivas, e a resina composta Viscalor Bulk Fill demonstrou excelentes resultados com mudanças consideráveis na integridade marginal, como consequência da tecnologia viscosa térmica e maior adaptabilidade de restaurações nas paredes e margens da cavidade (AU)


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Microscopy, Electron, Scanning , Malocclusion, Angle Class I
14.
Braz. J. Pharm. Sci. (Online) ; 59: e22009, 2023. tab, graf
Article in English | LILACS | ID: biblio-1447565

ABSTRACT

Abstract Oxazolidine derivatives (OxD) have been described as third-line antibiotics and antitumoral agents. The inclusion complexes based on cyclodextrin could improve the solubility and bioavailability of these compounds. A novel synthetic OxD was used, and its inclusion complexes were based on 2-hydroxy-beta-cyclodextrin (2-HPßCD). We conducted an in silico study to evaluate the interaction capacity between OxD and 2-HPßCD. Characterization studies were performed through scanning electron microscopy (SEM), Fourier-transformed infrared (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR), X-ray diffraction (XRD), and thermal analyses. A kinetic study of the OxD was performed, including a cytotoxicity assay using peripheral blood mononuclear cells (PBMCs). The maximum increment of solubility was obtained at 70 mM OxD using 400 mM 2-HPßCD. SEM analyses and FTIR spectra indicated the formation of inclusion complexes. 1H-NMR presented chemical shifts that indicated 1:1 stoichiometry. Different thermal behaviors were obtained. The pharmacokinetic profile showed a short release time. Pure OxD and its inclusion complex did not exhibit cytotoxicity in PBMCs. In silico studies provided a foremost insight into the interactions between OxD and 2-HPßCD, including a higher solubility in water and an average releasing profile without toxicity in normal cells


Subject(s)
Solubility/drug effects , Cyclodextrins/agonists , Microscopy, Electron, Scanning/methods , Magnetic Resonance Spectroscopy/methods , Spectroscopy, Fourier Transform Infrared/methods , Proton Magnetic Resonance Spectroscopy/methods , Anti-Bacterial Agents/analysis
15.
Pesqui. bras. odontopediatria clín. integr ; 23: e210155, 2023. tab, graf
Article in English | LILACS, BBO | ID: biblio-1507020

ABSTRACT

ABSTRACT Objective: To evaluate the mechanical properties of mini-implants (MIs) manufactured from stainless steel and compare them with conventional titanium-aluminum-vanadium alloy MIs. Material and Methods: The following groups were formed: G1 (n=24), 8×1.5 mm steel MIs; G2 (n=24), 12×2.0 mm steel MIs; and G3 (n=24), 10×1.5 mm titanium MIs. The 72 MIs were inserted in the infra zygomatic crest region of the maxilla and retromolar trigone in the jaw of 10 pigs. Pull-out, insertion torque, fracture and percussion tests were performed in order to measure the tensile strength, primary stability and fracture strength of MIs. A digital torque gauge was used to measure insertion and fracture torque, a universal mechanical testing machine was used for pull-out testing and a periotest device was used to measure the micromovement of MIs. For morphological and MI component evaluation, scanning electron microscopy (SEM) was performed. D'Agostino & Pearson, Kruskal-Wallis, and Dunn post-hoc and normality tests were used. Results: G2 insertion and fracture torques were significantly higher than G1 and G3 insertion and fracture torques (p<0.05). The pull-out and percussion tests presented similar values among the groups. SEM revealed that the fracture point was predominantly on the fourth thread for steel MIs (G1 and G2) and on the seventh thread for titanium-aluminum-vanadium MIs (G3). Conclusion: The mechanical properties of stainless steel MIs are superior to those of titanium-aluminum-vanadium alloy MIs.


Subject(s)
Animals , Stainless Steel/chemistry , Tensile Strength , Titanium , Orthodontic Anchorage Procedures/instrumentation , Swine , Microscopy, Electron, Scanning/instrumentation , Statistics, Nonparametric , Flexural Strength , Mechanical Tests
16.
Braz. j. oral sci ; 22: e239079, Jan.-Dec. 2023. ilus
Article in English | LILACS, BBO | ID: biblio-1413365

ABSTRACT

Aim: To evaluate the marginal fit of protocol bars milled from digital models obtained by conventional molding followed by bench scanning or digital molding with an intraoral scanner. Methods: Four morse-cone implants and the mini-pillars were installed in a 3D printed mandible model (master model). Digital models of the master model were obtained by (n=10): (Group A - Conventional) conventional (analog) molding of the master model followed by bench scanning or (Group B - Digital) molding of the master model with an intraoral scanner. All-on-four protocol bars were designed and milled from the digital models for both groups and screwed into the master model. Scanning electron microscopy (SEM) images from the distal, central, and mesial regions of each implant were obtained and the implant-protocol bar marginal fit was measured in an image software (Image J). The mean misfit of each region was analyzed by two-factor ANOVA, Tukey test, and Student's t-test (0,05 = 0.05). Results: The digital approach (B) showed higher misadaptation than the conventional approach (A, p < 0.05), regardless of the region evaluated. In group A, the central region showed higher maladjustment than the mesial region (p<0.05), however, there were no differences among regions of group B (p>0.05). Conclusion: The conventional method of acquiring digital models using the bench scanner produced bars for the All-On-Four protocol with better marginal fit than the digital models obtained with an intraoral scanner


Subject(s)
Microscopy, Electron, Scanning , Dental Implants , Computer-Aided Design
17.
Braz. j. oral sci ; 22: e239389, Jan.-Dec. 2023. ilus
Article in English | LILACS, BBO | ID: biblio-1509457

ABSTRACT

Aim: The purpose of this study was to investigate the biofilm effect on the hybrid ceramic-resin cement bond strength (BS) by comparing two methods. Methods: Teeth were distributed into groups (n=5), according to the resin cement (Maxcem Elite-(MC) or NX3 Nexus-(NX)) and degradation method (24h or 7 days in distilled water; 7 or 30 days incubated with biofilm and 30 days in sterile media). Treated surfaces of Vita Enamic blocks (5x6x7mm) were luted to treated or no treated dentin surfaces and light-cured. After 24h, beams were obtained (1x1x10mm) and stored accordingly. The flexural bond strength (FBS) was assessed by four-point bending test. Additional beams were obtained from new teeth (n=5), stored for 24h or 7 days in distilled water, and submitted to a microtensile bond strength (µTBS) assay. Failure modes were determined by scanning electron microscopy (100X). The flexure strength of the cements (n=10) was assessed by a four-point bending test. Data were analyzed by 1 and 2-ways ANOVA, and Tukey's test (α=0.05). Results: There was no significant difference between the degradation methods for the FBS groups. For the µTBS, the significant difference was as follows: NX 7days > NX 24h > MC 7days = MC 24h. Failure mode was mainly adhesive and mixed, but with an increase of cohesive within cement and pre-failures for the MC groups assessed by µTBS. NX had better performance than MC, regardless of the method. Conclusions: The biofilm had no effect on the materials BS and FBS test was a useful method to evaluate BS of materials with poor performance


Subject(s)
Tensile Strength , Microscopy, Electron, Scanning , Dental Bonding , Biofilms , Resin Cements
18.
Braz. j. oral sci ; 22: e238692, Jan.-Dec. 2023. ilus
Article in English | LILACS, BBO | ID: biblio-1509506

ABSTRACT

Aim: This study investigated the influence in vitro of different sodium hypochlorite (NaOCl) agitation protocols associated or not with DualRinse (HEDP) on the temperature of the solution. Methods: Forty-eight premolars were instrumented and their apical third sealed to allow a closed irrigation system. The teeth remained immersed in a basin of warm water (37°C). The teeth were divided into the groups: G1 (NaOCl+Passive Ultrasonic Irrigation (PUI)), G2 (NaOCl/HEDP + PUI), G3 (NaOCl + EasyClean (EC)) and G4 (NaOCl/HEDP + EC). The canals were filled with the respective solutions and after 180 seconds the first temperature measurement was taken (T0). Then, the solutions were agitated, following the different protocols, for 60 seconds and a new measurement was performed (T60). The temperature was measured using a digital thermometer for type "K" sensors that was inserted into the middle third of the teeth. At the end of the measurements, the teeth were sectioned and prepared for scanning electron microscopy. The dentinal wall of middle third was graded according to the amount of debris and smear layer remaining on the walls. The results were analyzed using ANOVA test and Tukey's multiple comparisons (p<0.05). Results: G1 and G2 had an average increase in temperature of 1.1°C and 1.65°C, respectively (p>0.05). EasyClean caused a decrease in the temperature of the solutions in both groups, without a significant statistical difference with T0 (p>0.05). Regarding cleaning, it was only possible to observe clean dentinal tubules in the groups with the chelator. PUI discretely increased the temperature of the solution, regardless of the solution. The opposite effect was observed after activation with EasyClean. Conclusion: The association of NaOCl with a chelating agent promoted the cleaning of the dentinal tubules


Subject(s)
Root Canal Irrigants , Sodium Hypochlorite , Temperature , Ultrasonics , Microscopy, Electron, Scanning , Chelating Agents
19.
Article in English | LILACS, BBO | ID: biblio-1507024

ABSTRACT

ABSTRACT Objective: To assess the efficacy of 5% Glycolic Acid (GA), 17% ethylenediaminetetraacetic acid (EDTA) and 7% maleic acid (MA), in removing the smear layer (SL). Material and Methods: For the experiment, forty single-rooted human teeth were selected. To perform the chemo‑mechanical preparation, the root canals were instrumented to an apical size of #30, along with simultaneous irrigation of 2.5% NaOCl. The samples were allotted to the experimental groups based on the final irrigating solution (n=10): (1) The GA group: 05%, (2) the EDTA group: 17%, (3) the MA group: 7%, and (4) the control group: Distilled water. The teeth were evaluated for the presence or absence of SL using SEM. Results: Comparing the 5% GA, 7% MA and 17% EDTA groups, no statistically significant differences were found at the coronal and middle thirds (p>0.05). However, in the apical third, MA had greater efficacy than EDTA (p=0.002) and GA (p=0.041), with a significant difference in the SL removal, while there was no significant difference between the latter (p=0.148). Conclusion: Thus, it was concluded that 7% maleic acid as a final irrigating solution is more efficacious than 17% EDTA and 5% glycolic acid in eliminating the smear layer from the apical portion of the root canal.


Subject(s)
Humans , Smear Layer , Edetic Acid/chemistry , Root Canal Preparation/instrumentation , Dental Pulp Cavity , Microscopy, Electron, Scanning/instrumentation , Chi-Square Distribution , Statistics, Nonparametric
20.
Braz. j. oral sci ; 22: e238637, Jan.-Dec. 2023. ilus
Article in English | LILACS, BBO | ID: biblio-1512222

ABSTRACT

The objective of this study was to evaluate the effect of abrasion wear on surface roughness and microhardness of different commercially available resin composites simulating pH-challenges of the oral cavity. Methods: Three resin composites (RC) were used in this study: one conventional: Z250; and two bulk fill resin composites (BRC): Tetric N-Ceram (TNC) and Sonic Fill (SF). The RC was inserted in a prefabricated mold (15mm wide x 4mm thickness) in two layers, or in a single layer for BRC. Thirty samples were prepared and surface roughness (Ra) and Knoop microhardness (KHN) test were performed at three different time-points of evaluation: baseline (24h after sample preparation); partial (after pH cycling); and final (after simulated toothbrushing procedure). Two samples of each group were selected after different treatments and analyzed descriptively on a scanning electron microscopy (SEM). Data from Ra and KHN were analyzed by two-way repeated-measures ANOVA and Bonferroni's post-hoc test with a significance level set at 5%. Results: Ra increased for all groups (p<0.001), at the final time-point, Z250 and TNC groups present the highest values. Oppositely, KHN decreased for all groups (p<0.001), Z250 group showed the highest KHN values for all time-points (p<0.001). The SEM imagens showed a regular surface for samples cycled and irregular with inorganic particles exposed for samples toothbrushed. Conclusion: pH-cycling and simulated toothbrushing affected the superficial properties (roughness and Knoop microhardness), as observed at SEM imagens, with irregular surface with inorganic particles exposure


Subject(s)
Surface Properties , Toothbrushing , Microscopy, Electron, Scanning , Composite Resins
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