Quantitative interactions between Candida albicans and the mutans streptococci in patients with Down Syndrome

BACKGROUND: Oral microorganisms produce damage through the transfer to bloodstream, colonizing other tissues or direct damage in the oral cavity. Aim to study the quantitative interactions between C. albicans and the mutans streptococci and ms serotypes in the saliva of the oral cavity of patients with Down syndrome (DS). MATERIAL AND METHODS: Included 120 patients of both genders, 60 patients with Down syndrome (DS) and 60 patients as a control group (CG). Samples of saliva were taken, and bacteria and fungi were grown on TYCSB and Saboureaud agar. Microbiological, serological and quantitative analyses were performed to determine the kind of isolated of microorganisms corresponding to the ms c, e, f and k for species S. mutans and d and g for S. sobrinus and C. albicans. Electronic scanning microscopy was employed to visualize and confirm the colonies under study. Statistics analysis included t-test proofs for matched data test, Scheffé and ANOVA. RESULTS: Forming units (CFU) per mL of saliva of C. albicans a significant difference was observed among DS < CG groups. A correlation of the C. albicans quantity and the ms count was found by age intervals however, tendencies were different in SD and CG. Also, the CFU of C. albicans was different among the serotypes of ms (c, e, f, k < d, g, h, < notyped). CONCLUSIONS: These results show a significant non-random association between these two commensal microorganisms in different patient groups

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The microanatomy of Bowman's layer in the cornea of the pig: Changes in collagen fibril architecture at the corneoscleral limbus

In most animals, Bowman's layer is a feature of the cornea of the eye, and lies between the sur-face epithelium and the stromal extracellular matrix that makes up the bulk of the cornea. It is comprised of a condensation of disorganised collagen fibrils. However, it has been conjectured that not all species possess Bowman’s layer, and pigs are a species that has classically been stated to lack this anatomical structure, although there is disagreement in the published literature. Here, we studied the porcine cornea using transmission and scanning electron microscopy (TEM and SEM) to ascertain whether Bowman’s layer existed. TEM identified a thin band of disorganised collagen fibrils between the epithelial basement membrane and corneal stroma. SEM images of the central and peripheral corneal surfaces, following removal of the corneal epithelium by cell maceration, revealed a disorganised meshwork of collagen fibrils, with a highly aligned annulus of collagen at the limbus. In between the peripheral cornea and limbus, a "transition zone" is observed where collagenfibrils start to align. Quantification of fibril alignment demonstrates a significant increase in collagen alignment from 0.08 ± 0.04 to 0.33 ± 0.07 (p < 0.001; n = 60; 0 = no alignment, 1 = full alignment) with increasing distance from the corneal centre. These data together lead us to conclude that the porcine cornea does include Bowman's layer, though it is thin (contributing roughly 0.2% of corneal thickness), and thus, reaffirms the porcine cornea's similarity to its human counterpart and usefulness as a model system

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Fracture resistance after implantoplasty in three implant-abutment connection designs

BACKGROUND: To assess the effect of implantoplasty and implant-abutment design on the fracture resistance and macroscopic morphology of narrow-diameter (3.5 mm) dental implants. MATERIAL AND METHODS: SCREW-shaped titanium dental implants (n = 48) were studied in vitro. Three groups (n = 16) were established, based on implant-abutment connection type: external hexagon, internal hexagon and conical. Eight implants from each group were subjected to an implantoplasty procedure; the remaining 8 implants served as controls. Implant wall thickness was recorded. All samples were subjected to a static strength test. RESULTS: The mean wall thickness reductions varied between 106.46 and 153.75 μm. The mean fracture strengths for the control and test groups were, respectively, 1211.90 ± 89.95 N and 873.11 ± 92.37 N in the external hexagon implants; 918.41 ± 97.19 N and 661.29 ± 58.03 N in the internal hexagon implants; and 1058.67 ± 114.05 N and 747.32 ± 90.05 N in the conical connection implants. Implant wall thickness and fracture resistance (P < 0.001) showed a positive correlation. Fracture strength was influenced by both implantoplasty (P < 0.001) and connection type (P < 0.001). CONCLUSIONS: Implantoplasty in diameter-reduced implants decreases implant wall thickness and fracture resistance, and varies depending on the implant-abutment connection. Internal hexagon and conical connection implants seem to be more prone to fracture after implantoplasty

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Measurement of gap between abutment and fixture in dental conical connection implants. A focused ion beam SEM observation

BACKGROUND: The aim of the authors was to examine the abutment-fixture interface in Morse-type conical implants in order to verify gaps at this level using a new microscopical approach. MATERIAL AND METHODS: In this in vitro study, 20 abutment-fixture complexes were prepared by sectioning (longitudinal and cross-sectional to the long axis) with a microtome and then with a focused ion beam (FIB). This is a micrometric machine tool that uses gallium ions to abrade circumscribed areas to dig deeper into the cuts obtained with the microtome in order to eliminate cut-induced artifacts. This is because the FIB abrasion is practically free from artifacts, which are normally generated by the action of the microtome blades or other techniques. Samples were then observed by scanning electron microscopy (SEM). RESULTS: The observation of the abraded parts with the FIB permitted measurement of the real gap between the implant-abutment components. A variable amount of gap was retrieved (from 0 to 3 μm) by the observations, confirming the non-hermetic nature of the connection. It has to be pointed out that in approximately 65% of cases, the gap accounted for less than 1 μm. CONCLUSIONS: The reported data confirmed that the analyzed connection system allowed for minimal gap. However, from the evidence of the present analysis, it cannot be assumed that the 2 parts of a Morse-type conical implant are fused in 1 piece, which would create a perfectly matched hermetic connection

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Assessing osseointegration of metallic implants with boronized surface treatment

BACKGROUND: Modification of endosteal implants through surface treatments have been investigated to improve osseointegration. Boronization has demonstrated favorable mechanical properties, but limited studies have assessed translational, in vivo outcomes. This study investigated the effect of implant surface boronization on bone healing. MATERIAL AND METHODS: Two implant surface roughness profiles (acid etched, machined) in CP titanium (type II) alloy implants were boronized by solid-state diffusion until 10-15 µm boron coating was achieved. The surface-treated implants were placed bilaterally into 5 adult sheep ilia for three and six weeks. Four implant groups were tested: boronized machined (BM), boronized acid-etched (BAA), control machined (CM), and control acid-etched (CAA). Osseointegration was quantified by calculating bone to implant contact (BIC) and bone area fraction occupancy (BAFO). RESULTS: Both implant types treated with boronization had BIC values not statistically different from machined control implants at t=3 weeks, and significantly less than acid-etched control (p < 0.02). BAFO values were not statistically different for all 3-week groups except machined control (significantly less at p < 0.02). BAFO had a significant downward trend from 3 to 6 weeks in both boronized implant types (p < 0.03) while both control implant types had significant increases in BIC and BAFO from 3 to 6 weeks. CONCLUSIONS: Non-decalcified histology depicted intramembranous-like healing/remodeling in bone for controls, but an absence of this dynamic process in bone for boronized implants. These findings are inconsistent with in vitro work describing bone regenerative properties of elemental Boron and suggests that effects of boron on in vivobone healing warrant further investigation

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Candida albicans biofilms on different materials for manufacturing implant abutments and prostheses

BACKGROUND: Morphological, physical and chemical properties of both implants and prostheses can determine the biofilm formation on their surface and increase the risk of biological complications. The aim of this study was to evaluate the capacity of biofilm formation of Candida albicans on different materials used to manufacture abutments and prostheses. MATERIAL AND METHODS: Biofilm formation was analyzed on cp grade II titanium, cobalt-chromium alloy and zirconia, silicone, acrylic resin (polymethylmethacrylate) and nano-hybrid composite. Some samples were partially covered with lithium disilicate glass ceramic to study specifically the junction areas. C. albicans was incubated in a biofilm reactor at 37 °C with agitation. The biofilm formation was evaluated at 24 and 48 hours. In addition, the morphology of the biofilm was evaluated by scanning electron microscopy. RESULTS: C. albicans developed biofilms on the surface of all materials tested. Cobalt-chromium alloy showed the lowest density of adhered biofilm, followed by zirconia and titanium. Silicone and resin showed up to 20 times higher density of biofilm. A higher biofilm formation was observed when junctions of materials presented micro-pores or imperfections. CONCLUSIONS: The biofilm formed in the three materials used in the manufacture of abutments and prostheses showed no major differences, being far less dense than in the resins. Two clinical recommendations can be made: to avoid the presence of resins in the subgingival area of implant prostheses and to design prostheses placing cobalt-chromium alloy/ceramic or titanium/ceramic junctions as far as possible from implants

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Clinicopathological and ultrastructural characterization of periapical actinomycosis

BACKGROUND: The aim of the present study was to analyze the clinicopathological and the ultrastructural features of periapical actinomycosis (PA) cases. MATERIAL AND METHODS: Data from the files of an oral pathology laboratory were retrieved and the findings of histopathological analysis were evaluated. Hematoxylin-eosin (HE), a modified Brown & Brenn, and Grocott stains as well as ultrastructural analysis using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were utilized. RESULTS: Six cases were obtained, 4 females and 2 males, with a mean age of 34 year-old. Two cases were symptomatic, lower teeth and the anterior region were more commonly affected, and all cases were characterized by periapical radiolucencies. All cases presented sulfur granules with a ray-fungus or club-shaped pattern of the Splendore-Hoeppli phenomenon in HE-stained sections, with filamentous gram-positive bacteria aggregates highlighted by the modified Brown & Brenn stain. SEM analysis revealed abundant packed rod-like and filamentous bacteria associated with an extracellular amorphous material. EDX analysis showed predominant picks of calcium and sulfur in actinomycotic colonies. CONCLUSIONS: Our findings suggest that PA manifests either clinically and radiologically as a non-specific and heterogeneous condition and that the actinomycotic colonies consist in a calcium- and sulfur-rich matrix. Furthermore, the results highlight the importance of submitting periapical specimens after surgical removal to histopathological análisis

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Valoración de la adhesión bacteriana en implantes orbitarios expuestos mediante microscopia electrónica y cultivo microbiológico / Evaluation of bacterial adhesion in exposed orbital implants using electron microscopy and microbiological culture

Se presentan tres casos de pacientes anoftálmicos con implantes orbitarios expuestos. Aunque solo un paciente mostraba signos clínicos evidentes de infección, los tres implantes fueron estudiados para determinar la presencia de microorganismos adheridos a su superficie mediante microscopia electrónica de barrido (MEB) y cultivo microbiológico. La MEB permitió la visualización de microorganismos adheridos a los tres implantes, si bien solo uno de ellos presentó crecimiento en los cultivos microbiológicos. Además, la técnica de MEB empleada en el caso número 3 consiguió una mejor orientación y apreciación de los microorganismos respecto a las imágenes de los casos número 1 y 2. Estos hallazgos apoyan la idea de que la superficie de los implantes orbitarios expuestos está colonizada por microorganismos incluso cuando todavía no muestran signos evidentes de infección. Por lo tanto, es necesario una eliminación mecánica de la superficie expuesta del implante antes de recubrirla con injertos o colgajos

Three cases are presented of anophthalmic patients with exposed orbital implants. Although only one patient showed evident clinical signs of infection, all three implants were studied to determine the presence of microorganisms adhered to their surface using a scanning electron microscopy (SEM) and microbiological culture. The SEM allowed the visualisation of microorganisms adhered to the three implants, although only one of them showed growth in the microbiological cultures. In addition, the SEM technique used in case No. 3 achieved a better orientation and appreciation of the microorganisms with respect to the images of cases No. 1 and 2. These findings support the idea that the surface of exposed orbital implants is colonised by microorganisms, even when they still do not show obvious signs of infection. Therefore, mechanical removal of the exposed surface of the implant is necessary before covering it with grafts or flaps

Chytridiomycosis in amphibians / Quitridiomicosis en anfibios

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Estudio comparativo de divisibilidad de diferentes formulaciones de prednisona / Comparative study on the divisibility of different prednisone formulations

El objetivo de este trabajo fue estudiar la influencia de la divisibilidad en comprimidos de prednisona 30 mg. La división de comprimidos se utiliza a menudo en la práctica farmacéutica para ajustar las dosis administradas. La prednisona es un corticoesteroide (glucocorticoide) utilizado en el tratamiento de sustitución en la insuficiencia adrenal incluyendo entre otras la enfermedad de Addison. Como medicamento de referencia se utilizó Dacortin 30 mg, el cual se comparó con dos medicamentos genéricos. Se estudiaron diferentes características farmacotécnicas para evaluar la calidad de los comprimidos estudiados, tales como la disgregación y la resistencia a la rotura. Atendiendo al estudio de fraccionamiento de comprimidos, se determinó la diferencia sobre el peso teórico esperado (pérdida de masa media tras el fraccionamiento de cada marca comercial). La liberación del principio activo se estudió mediante el ensayo de velocidad de disolución en fracciones de comprimidos. Los resultados de las tres presentaciones comerciales fueron estudiados y analizados estadísticamente con un nivel de confianza de un 95 %

The objective of this work was to study the influence of the division in prednisone tablets 30 mg. The division of tablets is often used in pharmaceutical practice to adjust the administered doses. Prednisone is a corticosteroid (glucocorticoid) used in the substitution treatment in adrenal insufficiency including, among others, Addison's disease. As a reference drug, Dacortin 30 mg was used, and compared with two generic drugs. Different pharmacotechnic characteristics were studied to evaluate the quality of the tablets studied, such as disintegration, and the resistance to crushing. Based on the study of tablet fractionation, the difference over the expected theoretical weight was determined (loss of average mass after the fractionation of each trademark). The release of the active substance was carried out with dissolution rate study in fractions of tablets. The results of the three commercial formulations were studied and statistically analyzed with a confidence level of 95 %

Biosynthesis of chemical compounds by Candida albicans and Candida glabrata / Biosíntesis de compuestos químicos por Candida albicans y Candida glabrata

Background: In the last three decades the species of Candida have been of great interest due to the high mortality rates that they cause in immunocompromised and hospitalized patients. These species are opportunistic pathogens and they have inhabited other environments long before colonizing human cells. Among these environments we find wastewater from mines, and water from aquifers and soils that contain high concentrations of precious metals as well as toxic and base metals. Aims: The aim of this study was to assess whether Candida albicans and Candida glabrata are able to maintain homeostasis in the presence of zinc, copper, cobalt or silver. Methods: To achieve the objective, each of the Candida species was exposed to every single metal individually in a salt solution. Subsequently the treated cells were lysed to evaluate the compounds formed by means of Scanning Electron Microscopy-Energy Dispersive X-ray spectroscopy (SEM-EDS). Results: When analyzing the compounds that both C. albicans and C. glabrata formed in the presence of each of the metals, we found that they had synthesized silver sulfide (Ag2S), cobalt sulfate (CoSO4), zinc phosphate (Zn3(PO4)2), or copper oxide (CuO). Conclusions: Our results indicate that both C. albicans and C. glabrata have enzymatic and non-enzymatic mechanisms that allow them to achieve homeostasis in a different specific manner for each of the single metals to which they were exposed. To our knowledge, this is the first work reporting that C. albicans and C. glabrata can reduce different metals, with the subsequent formation of sulfides, sulfates, phosphates and oxides. This ability, developed over time by these Candida species, is probably a kind of biochemical mechanism in order to survive and colonize many different environments, from water or soil to humans. For this reason, C. albicans and C. glabrata make up an excellent model of study, both from a medical and biotechnical point of view

Antecedentes: Las especies de Candida han cobrado gran interés en las últimas tres décadas debido a los altos índices de mortalidad que ocasionan en pacientes inmunodeficientes y hospitalizados. Estas especies son consideradas patógenas oportunistas y existen otros medios ambientes que estas levaduras han habitado mucho antes de haber colonizado al ser humano: aguas residuales de minas, agua de mantos acuíferos y suelos que contienen altas concentraciones de metales preciosos, metales tóxicos y metales comunes. Objetivos: El objetivo del presente trabajo fue evaluar si Candida albicans y Candida glabrata eran capaces de mantener la homeostasis en presencia de los elementos químicos cinc, cobre, cobalto y plata. Métodos: Para lograr el objetivo, las dos levaduras fueron expuestas a cada uno de los metales elegidos de manera independiente, y posteriormente las células tratadas fueron lisadas para permitir la evaluación por medio de microscopía electrónica de barrido con espectrometría de dispersión de energía de rayos X (SEM-EDS) del compuesto formado. Resultados: Al analizar los compuestos que tanto C. albicans como C. glabrata formaron en presencia de cada metal, se encontró que habían sintetizado sulfuro de plata (Ag2S), sulfato de cobalto (CoSO4), fosfato de cinc (Zn3(PO4)2), u óxido de cobre (CuO). Conclusiones: Nuestros resultados indican que tanto C. albicans como C. glabrata poseen mecanismos enzimáticos y no enzimáticos que les permiten alcanzar una homeostasis de manera específica para cada metal al que son expuestas. A nuestro entendimiento este es el primer trabajo que documenta que C. albicans y C. glabrata pueden reducir distintos metales, con la subsecuente formación de sulfuros, sulfatos, fosfatos y óxidos. Esta habilidad que pudieron desarrollar a lo largo del tiempo estas especies de Candida para poder sobrevivir y colonizar medios ambientes tan diferentes, que van desde el agua o los suelos hasta el ser humano, las convierte en un excelente modelo de estudio, tanto desde el punto de vista médico como biotecnológico

Development and viability of biofilms grown on experimental abutments mimicking dental implants: An in vivo model

Background: To determine whether an experimental abutment mimicking the macro- and microstructure of a dental implant is a suitable method for recovering biofilm, and to describe the features of biofilms formed around such abutments on healthy implants. Material and Methods: Experimental abutments were used in 15 patients without peri-implant diseases. After 14 days' absence of dental hygiene in this area, the abutments were retrieved and analyzed through confocal laser scanning microscopy and scanning electron microscopy. The biofilm formation on the surface of the first 5 abut-ments was determined by a fluorescence-staining method using SYTO9 nucleic acid stain. In order to study the biofilm's coverage and vitality, 10 additional abutments were assessed using live & dead bacterial viability. Descriptive and bivariate analyses of the data were performed. Results: A global plaque coverage of the abutments was observed in all cases. The submucosal area of the abutment was mostly covered with biofilm (over 21%). Moreover, significant differences between supra- and subgingival locations were detected. Conclusions: This in vivo experimental model allows detailed observation of the extensive plaque growth found on exposed experimental abutments mimicking dental implants when hygiene measures are absent. The biofilm cover-age is significantly higher in the supragingival zone than in the subgingival portion

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Combination Therapy of Clinically Approved Antifungal Drugs Is Enhanced by Conjugation with Silver Nanoparticles

Silver nanoparticles (SN) have been recently developed as a new class of antimicrobial agents against numerous pathogenic microorganisms. SN have also been used as efficient drug delivery systems and have been linked with increasing drug potency. Here, we demonstrated the enhanced antifungal efficacy of nystatin (NYT) and fluconazole (FLU) after conjugation with SN. The antifungal bioactivity of NYT- and FLU-coated SN was evaluated against Candida albicans ATCC 10231 and Aspergillus brasiliensis ATCC 16404 by the agar tube dilution method. The aim of this study was to determine and compare the antifungal efficacy of NYT and FLU with their SN and, finally, the combination of both nanoparticles as NYT-SN + FLU-SN against pathogenic fungi. The results indicated that all test samples showed a dose-dependent response against tested fungi. SN significantly enhanced the antifungal effects of NYT and FLU as compared to drugs alone. We observed a remarkable increase in the percent inhibition of both fungi (90-100%) when treated with a combination of both nanoparticles NYT-SN + FLU-SN at 200 μg/mL only. Furthermore, the morphological modifications occurred at the surface of fungal species were also analyzed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). While tested against primary human cell line, all SN showed negligible cytotoxicity. Hence, these results suggest that the combination of SN with NYT and FLU may have clinical implications in the treatment of fungal infections. However, in vivo studies are needed before recommending the use of these nanoparticles safely in clinical situations

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Evaluación de la penetración de cementos obturadores de canales mediante microscopía electrónica de barrido / Evaluation of the penetration of root canal filling cements through scanning electron microscopy

Antecedentes: la literatura odontológica demuestra que los tratamientos endodónticos fallidos, comúnmente son debidos a la persistencia de los microorganismos. Una característica importante de los cementos obturadores de canales es su habilidad para penetrar en los túbulos dentinarios, logrando así un sellado impermeable entre las paredes dentinarias y el material de obturación central, reduciendo las filtraciones potenciales y aumentando la resistencia a la fractura. Objetivo: Evaluar mediante microscopía electrónica de barrido (MEB) la penetración de MTA Fillapex, cemento de Grossman (CG) y top seal a lo largo del conducto radicular. Materiales y métodos: Estudio experimental in vitro, en 36 dientes premolares humanos divididos aleatoriamente en 3 grupos, (n= 12), los cuales fueron preparados con técnica endodóntica Step Back. Cada grupo se dividió en 2 subgrupos utilizando como irrigante NaOCl al 2,5%, al igual que NaOCl al 2,5% + EDTA al 17%. Los canales fueron obturados con técnica de condensación lateral, seccionados longitudinalmente para observar mediante microscopia electrónica de barrido a nivel de los tercios cervical, medio y apical, la penetración del cemento al interior de los túbulos dentinarios. Se realizó análisis estadístico con SPSS v 22 IBM con p< 0,05 y las pruebas Kruskal-Wallis y Mann-Whitney. Resultados: Mediante la prueba Kruskal-Wallis, los cementos de Grossman y top seal al utilizar NaOCl + EDTA presentaron valores de p= 0,025 y p= 0,002 en los tercios medio y apical respectivamente. La prueba de Mann Whitney mostró un valor p= 0,031 en el tercio apical para el cemento MTA Fillapex al utilizar NaOCl. Los valores de la mediana fueron MTA Fillapex tercio medio= 2,0000, tercio apical= 1,0000; top seal tercios medio y apical= 4,0000; cemento de Grossman tercios medio y apical= 4,0000. Al ser igual el valor de la mediana entre los cementos top seal y Grossman se utilizaron los valores de la varianza con un resultado estadísticamente significativo para el cemento de Grossman= 0,276 en el tercio medio y top seal= 0,176 en el tercio apical. La prueba de Mann Whitney arrojó un valor p= 0,031 en el tercio apical para el cemento MTA Fillapex. Con un valor de mediana de NaOCl= 3,0000, NaOCl + EDTA= 1,0000. Conclusiones: Al comparar los cementos obturadores MTA Fillapex, top seal y cemento de Grossman utilizando como irrigante NaOCl + EDTA se observó mayor penetración del cemento de Grossman. A nivel del tercio apical se observó mayor penetración con el cemento top seal. El cemento obturador MTA Fillapex presentó mayor penetración a nivel del tercio apical al utilizar como irrigante NaOC (AU)

Background: the literature has shown that failed endodontic treatments are commonly due to the persistence of microorganisms. One important characteristic of root canal filling cements is their ability to penetrate the dentinal tubules, achieving an impermeable sealing between the dentinal walls and the central filling material, reducing potential filtrations and increasing the resistance to fracture. Objective: To evaluate through scanning electron microscopy (SEM) the penetration of MTA Fillapex, Grossman sealer and top seal all along the root canal. Methods: In vitro experimental study, in 36 human teeth randomly divided into 3 groups, (n= 12), which were prepared with the Step Back endodontic technique. Each group was divided into 2 subgroups using NaOCl 2.5%, and NaOCl 2.5% + EDTA 17% as irrigating solutions. The root canals were sealed using the lateral condensation technique, longitudinally sectioned to observe through scanning electron microscopy the cervical, medium and apical thirds, the penetration of the cement inside the dentinal tubules. The statistical analysis was performed with SPSS v22 IBM with p < 0.05 and the Kruskal-Wallis and Mann-Whitney tests. Results: through the Kruskal- Wallis test the Grossman sealer and top seal when using NaOCl + EDTA showed values of p= 0.025 and p= 0.002 in the medium and apical thirds respectively. The Mann-Whitney test showed a value of p= 0.031 in the apical third for the MTA Fillapex when using NaOCl. The median values were MTA Fillapex medium third= 2.000, apical third= 1.000; top seal medium and apical thirds= 4.000. Since the median values between the top seal and Grossman sealer were the same, the values from the variance were used, with a statistically significant result for the Grossman sealer= 0.276 in the medium third and top seal = 0.176 in the apical third. The Mann-Whitney test showed a value p= 0.031 in the apical third for the MTA Fillapex. With a median value of NaOCl= 3.000, NaOCl + EDTA= 1.000. Conclusions: When comparing the filling cements MTA Fillapex, top seal and Grossman sealer using NaOCl + EDTA as an irrigating solution, more penetration from the Grossman sealer was observed in medium third. At the apical third, more penetration from the top seal sealer was observed. The MTA Fillapex cement showed the greatest penetration at the apical third when using NaOCl as an irrigating solution (AU)

Eliminación del barrillo dentinario en los conductos radiculares mediante irrigación con nuevas puntas de poliamida de activación sónica / Elimination of the root canal dentin smear layer by irrigation with new polyamide sonic-activated tips

Material y métodos: Estudio in vitro con dientes humanos monorradiculares (N = 40). La muestra se dividió en 4 grupos experimentales (ni = 10). Grupo I: irrigación con jeringa y punta de salida lateral sin activación. Grupo II: irrigación sónica con puntas de poliamida Eddy (TM). Grupo III: Irrigación con el sistema Endoactivator (R). Grupo IV: Irrigación con el sistema de activación ultrasónica pasiva (IRRI S (R)). La capacidad de eliminación de barrillo dentinario de cada uno de los sistemas fue evaluado mediante microscopía electrónica de barrido y con los índices de Torabinejad y de Serafino, en los tercios coronal, medio y apical de cada conducto. Los datos obtenidos fueron analizados con los test de Kruskal Wallis, Mann-Whitney y Wilcoxon (p ≤ 0,05). Resultados: No hubieron diferencias significativas en la capacidad de eliminación de barrillo dentinario en función del tercio radicular (p > 0,05). El grupo I mostró menor eficacia respecto a los otros grupos estudiados. El grupo IV obtuvo resultados levemente superiores que los otros grupos. Conclusiones: Ningún sistema de los estudiados elimina la totalidad del barrillo

Objective: To compare the efficacy of polyamide sonic activation tips in eliminating the dentin smear layer from root canals versus other activation systems used during irrigation. Material and methods: An in vitro study was made using single-root human teeth (N = 40). The sample was divided into four experimental groups (ni = 10). Group I: irrigation using a side port syringe without activation; Group II: sonic irrigation with Eddy (TM) polyamide tips; Group III: irrigation with the Endoactivator(R); Group IV: irrigation using the IRRI S (R) passive ultrasonic activation system. The dentin smear eliminating capacity of each system was evaluated by scanning electron microscopy and using the indices of Torabinejad and Serafino, in the coronal, middle and apical thirds of each canal. The data obtained were analyzed with the Kruskal-Wallis test, Mann-Whitney U-test and the Wilcoxon test. Statistical significance was considered for p ≤ 0.05. Results: There were no significant differences in smear la-yer eliminating capacity (p > 0.05) among the different root thirds. Group I showed less efficacy than the other groups. Group IV yielded slightly better results than the other groups. Conclusions: None of the studied systems were able to fully eliminate the smear layer

Studies of ternary systems of sulfadiazine with Beta-cyclodextrin and aminoacids / Estudios de sistemas ternarios de sulfadiazina con Beta-ciclodextrina y aminoácidos

Introduction: Cyclodextrins (CD), are known to form inclusion complexes with a variety of guest molecules both in solution and in the solid state. This can lead to the alteration of properties of guest molecules. Unfortunately, the complexation efficiency of CD is rather low, and can be enhanced by formation of ternary complexes using aminoacids (AA). Sulfadiazine (SDZ) is an antibiotic with extremely low water solubility which limits its therapeutic applications and bioavailability. Objetives: The aim of this work was to increase the aqueous solubility of SDZ by preparing ternary complexes of this drug with β-cyclodextrin (βCD) and an AA as a third auxiliary substance. Materials y Methods: Complex formation was studied by phase solubility analysis (PSA), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and scanning electron microscopy (SEM). Results: The apparent stability constants (KC) of the multicomponent complexes were calculated from the solubility diagrams. By the analysis of the NMR spectra, it could be said that the shifts of some protons evidenced the important role of the AA in the formation of multicomponent complexes. Among the AA, Arginine (ARG) proved to have better solubilizing properties for SDZ, reaching an improvement up to 70 times. The use of DSC, TG and SEM suggested the formation of new solid phases between SDZ:βCD:AA. Conclusions: As a result of this research, it was determined that ternary products were more effective in improving drug solubility than the corresponding SDZ:βCD binary system

Introducción: Las ciclodextrinas (CD), son capaces de formar complejos de inclusión con una variedad de moléculas huésped, tanto en solución y en estado sólido, pudiendo producir la modificación de las propiedades de las moléculas huésped. Desafortunadamente, la eficiencia de la formación de complejos con CD es baja, lo cual se puede mejorar mediante la formación de complejos ternarios utilizando aminoácidos (AA). Sulfadiazina (SDZ) es un antibiótico con muy baja solubilidad en agua que limita su biodisponibilidad y sus aplicaciones terapéuticas. Objetivos: El objetivo de este trabajo fue aumentar la solubilidad acuosa de SDZ mediante la preparación de complejos ternarios con β-ciclodextrina (βCD) y un AA como una tercera sustancia. Materiales y Métodos: La formación de complejos se estudió por análisis de solubilidad de fases (PSA), resonancia magnética nuclear (RMN), calorimetría diferencial de barrido (DSC), análisis termogravimétrico (TG) y microscopía electrónica de barrido (SEM). Resultados: Las constantes de estabilidad aparente (KC) de los complejos multi-componentes se calcularon a partir de los diagramas de solubilidad. Por el análisis de los espectros de RMN se constató, por los corrimientos de algunos protones, el papel importante de los AA en la formación de complejos ternarios. Entre los AA, arginina (ARG) demostró tener mejores propiedades de solubilización para SDZ, alcanzando una mejora de hasta 70 veces. El uso de DSC, TG y SEM sugirió la formación de nuevas fases sólidas entre SDZ:βCD:AA

Development and evaluation of isoniazid loaded silk fibroin microsphere / Desarrollo y evaluación de microesfera de seda Fibroin cargado de isoniacida

Aim: Current experimental investigation is dedicated to prepare microspheres with small size and good sphericity by Phase Separation method using Isoniazid (INH) as model drug. Silk fibroin has unique intrinsic qualities like biodegradability, biocompatibility or release properties and their tunable drug loading capacity. The delivery loading proficiency of the drug molecules in silk spheres be contingent on their charge, and hydrophobicity or subsequent in altered drug release profiles. Methods: In the present work Isoniazid loaded silk fibroin microsphere was prepared by using phase separation method. Microsphere was evaluated for Ultraviolet-visible spectroscopy, Fourier Transform infrared spectroscopy, Entrapment efficiency, Scanning electron microscopy Studies. Results: Scanning electron microscopy studies revealed that Isoniazid Loaded Silk Fibroin Microspheres were spherical. Entrapment Efficiency of Isoniazid loaded Microspheres of different Formulation from F1 to F5 was in range of 53 to 68 %. F3 showed 68.47 % entrapment Efficiency and the optimized formulation drug release was 93.56 % at 24 hours. Conclusion: Experimental report disclosed a new aqueous based formulation method for silk spheres with controllable shape or size and sphere. Isoniazid loaded silk microspheres may act as ideal nano formulation with elaborated studies

Objetivo: La investigación experimental en curso está dedicada a la preparación de microesferas de pequeño tamaño y buena esfericidad mediante el método de separación de fases con isoniazida (INH) como fármaco modélo. La fibroina de seda tiene cualidades intrínsecas únicas como la biodegradabilidad, biocompatibilidad o propiedades de liberación y su capacidad de carga de fármacos ajustable. La aptitud de entrega de carga de las moléculas de fármaco en las esferas de seda estar supeditada a su carga, y la hidrofobicidad o subsiguiente alteración en los perfiles de liberación de fármacos. Métodos: En el presente trabajo la microesfera de fibroina de seda cargada de isoniazida fue preparada utilizando el método de separación de fases. La microesfera fue evaluada por espectroscopia ultravioleta-visible, espectroscopia infrarroja con transformado de Fourier, se midió la eficiencia de atrapamiento y se estudios mediante microscopia electrónica de barrido. Resultados: Estudios con el microscopio de escaneo de electrones revelaron que las microesferas de fibroina cargada de isoniazida eran esféricas. La eficacia de atrapamiento de las microesferas de formulación diferente de F1 a F5 estuvo en el rango de 53 a 68 %. F3 mostró un 68,47 % de eficiencia de atrapamiento y tras optimizar la formulación de liberación de fármacos fue de 93,56 %, a las 24 horas

Miconazole Microsponges based topical delivery system for diaper dermatitis / Sistema de administración tópica basada en microesponjas de miconazol para la dermatitis del pañal

Aim: The current investigation was aimed to develop and optimize the microsponges of miconazole nitrate for treatment of diaper dermatitis for enhanced therapeutic effect. Material and Methods: Microsponges were developed by emulsion solvent diffusion technique using 23 factorial design. Fabricated microsponges were optimized in order to analyze the effects of independent variables on the encapsulation efficiency, particle size, surface topography and in vitro drug release. The optimized formulation was then incorporated into the gel and evaluated. Results: Particle size of all formulations was found to be uniform and scanning electron microscopy (SEM) indicates spherical shape and porous nature of microsponges. In vitro drug release studies of all formulations revealed the release rate within the range of 67%±0.09 to 80.6%± 0.68 at the end of 12 hours. On its basis, formulation F8 was selected and incorporated into the gel (CF8) which was evaluated for pH, viscosity, spreadability, in vitro drug diffusion studies, in vitro anti fungal studies and stability studies. Conclusion: The formulated microsponge-based gel of miconazole nitrate would be a capable substitute to traditional treatment for reliable and economical cure of diaper dermatitis

Objetivo: La presente investigación tuvo como objetivo desarrollar y optimizar las microesponjas de nitrato de miconazol para el tratamiento de la dermatitis del pañal para un efecto terapéutico mejorado. Material y métodos: Las microesponjas fueron desarrollados por emulsión técnica de difusión del disolvente usando un diseño factorial 23. Las microesponjas fabricadas han sido optimizadas con el fin de analizar los efectos de las variables independientes sobre la eficacia de encapsulación, tamaño de partícula, la topografía de la superficie y en la liberación de fármaco in vitro. A continuación, la formulación optimizada se incorporo en un gel y se evaluó. Resultados: Se encontró que el tamaño de partículas de todas las formulaciones fue uniforme y la microscopía electrónica de barrido (SEM) indicó forma esférica y de naturaleza porosa de las microesponjas. En la liberación del fármaco, estudios in vitro de todas las formulaciones, revelaron la velocidad de liberación dentro de un intervalo de 67±0,09% a 80,6±0,68% al cabo de 12 horas. Con esta base, La formulación F8 se seleccionó y se incorporó en el gel (CF8) en el que se evaluó el pH, viscosidad, capacidad de extensión, estudios de difusión in vitro del fármaco, estudios in vitro anti hongos y estudios de estabilidad. Conclusión: El gel a base de microesponja formulado de nitrato de miconazol sería un sustituto adecuado al tratamiento tradicional para la curación fiable y económica de la dermatitis del pañal

A mi hija no le crece el pelo / My Daughter's Hair Won’t Grow

No disponible

Efectividad de distintas técnicas de activación en la remoción de medicación de hidróxido de calcio de las paredes radiculares / Effectiveness of different activation techniques in the removal of calcium hydroxide medication from root canal walls

Objetivos: Investigar distintos protocolos de irrigación y soluciones para la remoción de hidróxido de calcio de las paredes radiculares mediante Microscopía Electrónica de Barrido (MEB). Metodología: Se seleccionó una muestra de 48 raíces palatinas de molares superiores. Los conductos fueron instrumentados, irrigados, secados y obturados con medicación a base de hidróxido de calcio. Los dientes fueron aleatoriamente asignados en 6 grupos, dependiendo de la técnica utilizada para activar hipoclorito sódico y Smear Clear para la remoción de la medicación intraconducto: Grupo 1, Irrigación positiva con jeringa (P), Grupo 2, Irrigación Ultrasónica (UI), Grupo 3, Irrigación por presión apical negativa (ANP), Grupo 4: Irrigación ultrasónica pasiva e irrigación por presión apical negativa (UI + ANP). Se incluyeron dos grupos control: Grupo 5: Grupo control positivo (C+), que fue obturado con hidróxido de calcio, pero no se eliminó del conducto, y Grupo 6: Grupo control negativo (C-), que no fue obturado con hidróxido de calcio. Todos los conductos fueron observados con microscopio electrónica de barrido (MEB). Se evaluó la presencia de material residual usando un sistema de medición en los tercios apical, medio y coronal. Los resultados fueron analizados estadísticamente mediante los test de Kruskal-Wallis y Bonferroni (p < 0,05). Resultados: Se encontraron diferencias estadísticamente significativas entre todos los grupos en todos los tercios a estudio (p < 0,05). El uso combinado de UI y ANP resultó en una remoción más eficiente de hidróxido de calcio de las paredes radiculares, independientemente del área analizada. Conclusiones: La utilización de irrigación ultrasónica pasiva e irrigación por presión apical negativa como activación final, sugiere una mejor limpieza de los conductos. Ninguna técnica es capaz de remover completamente el hidróxido de calcio de las paredes radiculares

Aim: To investigate different irrigation protocols and solutions to remove Ca(OH)2 from the root canal walls by using Scanning Electron Microscopy (SEM). Methodology. Forty-eight palatal roots from upper molars were selected. The root canals were instrumented, irrigated, dried and filled with a calcium hydroxide medication. Teeth were then randomly assigned to one of 6 groups depending on which technique was used to activate NaOCl and Smear Clear irrigants to remove medication: Group 1, Positive syringe irrigation (P); Group 2, Ultrasonic Irrigation (UI); Group 3, Apical Negative Pressure irrigation (ANP); Group 4, Passive Ultrasonic Irrigation and Apical Negative Pressure irrigation (UI + ANP). 2 control groups were also included: Group 5, positive control (C+), which were filled with calcium hydroxide that was not removed from the canal and Group 6, negative controls (C-), which were not filled with calcium hydroxide. All root canals were observed through SEM. Presence of residual material was evaluated using a score system for the coronal, middle, and apical portions. Data were statistically analysed using the Kruskal-Wallis and Bonferroni tests (P < 0.05). Results. There was a statistically significant difference among all groups at all root levels (P < 0.05). The combined use of UI and ANP irrigation resulted more efficient in the removal of calcium hydroxide from the root canal walls, irrespective of the area analyzed. Conclusions. The use of passive ultrasonic irrigation and apical negative pressure as a final activation is suggested to improve cleaning of the root canals. No technique is able to completely remove calcium hydroxide dressing from the root canal walls