Increased IL-12p70 and IL-8 Produced by Monocytes in Response to Streptococcus spp. and Actinomyces spp. Causals of Endodontic Primary Infections.

We sought to evaluate the effect of endodontic-causative microorganisms of primary infections on mononuclear cells such as CD14+, CD4+, CD8+, CD19+ and Tregs Foxp3+. Facultative anaerobic microorganisms were isolated from radicular conducts and peripheral blood samples, which were taken from patients with primary infections. Cellular cultures were performed with peripheral blood mononuclear cells (PBMC) with and without Actinomyces spp. and Streptococcus spp. during 48, 72, and 96 h of contact in culture (concentration 5 × 105 cells/well) in a round plate bound with 48 wells. Later, PBMC was collected for analysis by flow cytometry, with the monoclonal antibodies αCD14, αCD4, αCD8, αCD19 and αFoxp3, and acquired using an FACSCanto II cytometer. The supernatant of cellular cultures was analyzed for the quantification of inflammatory cytokines. Data analysis was performed in FlowJo v10.8.2 and FCAPArray software, and statistical analysis was performed using GraphPad v5.0. software. We observed an increase in the percentage of CD14+ cells in patients at different hours of cellular culture in the presence of both Actinomyces spp. and Streptococcus spp. microorganisms, compared to healthy controls. This study demonstrates the role played by the innate immune system in the pathogeny of endodontic primary infections, explaining the effects that generate the more common microorganisms in this oral pathology.

Efficacy of the HBW Ultrasonic Ring for retrieval of fragmented manual or rotatory instruments.

A study was conducted to evaluate the success rates of bypassing or removing fragments of instruments that had fractured within the roots of mandibular molars using a HBW Ultrasonic Ring. Forty extracted first permanent mandibular molars with root canal curvature were included. The teeth were distributed randomly into four groups according to the type of instrument and the root canal third where they had fractured. The success rate for removal of instrument fragments was 100% for both of two stainless steel groups, 90% for a nitinol middle third group, and 80% for a nitinol apical third group. The mean time required for instrument removal was around 40 min. The HBW Ultrasonic Ring showed acceptable experimental results for retrieval of broken instrument fragments.

Elimination of E. faecalis and C. albicans Biofilm: A comparison between single and multiple file systems in an Ex Vivo study

To evaluate whether the WaveOne Gold and Reciproc single file instrumentation systems, are effective in reducing the microbial load of a mixed biofilm and the cleaning of apical third compared to the Twisted File Adaptive system (multiple- file system). Seventy mesial roots of the first and second molars were included and randomly divided into three experimental groups (n=20, n=10 controls). Biofilms were formed inside canals over 31 days. After instrumentation with the unique file systems, WaveOne Gold and Reciproc and the multiple file system Twisted File Adaptive, using 2.25% sodium hypochlorite as an irrigant in all cases, a count of colony forming units was performed using serial dilutions, cleaning of the apical third was evaluated using scanning electron microscopy. Comparisons amongst groups were made by using parametric and non-parametric statistics, according to a normal or non-normal data distribution, respectively. No significant differences in the reduction of the microbial load after employing a single-file system in comparison to the multiple-file system were found; in addition, the cleaning of the apical third was similar for the three different instrumentation systems. The single-file system is equal in effectiveness compared with the multiple-file system in reducing the microbial load.

Evaluar si los sistemas de instrumentación de lima única, como WaveOne Gold y Reciproc son efectivos para reducir la carga microbiana de un biofilm mixto y la limpieza del tercio apical, comparado con los sistemas de limas múltiples, como Twisted File Adaptive. Setenta raíces mesiales de primeros y segundos molares fueron incluidos y divididos de forma aleatoria en tres grupos experimentales (n=20, n=10 controles). El biofilm fue formado en el interior de los conductos durante 31 días. Después se instrumentó con los sistemas de lima única (WaveOne Gold y Reciproc) y el sistema de limas múltiples Twisted File Adaptive, usando hipoclorito de sodio al 2.5% en todos los casos. El conteo de unidades formadoras de colonias se realizó usando diluciones seriales, la limpieza del tercio apical se evaluó empleando el microscopio electrónico de barrido. La comparación entre grupos se realizó con pruebas paramétricas y no paramétricas, de acuerdo con la distribución normal y no normal de los datos, respectivamente. No hubo una diferencia significativa en la reducción de la carga microbiana después de emplear los sistemas de lima única en comparación a los de limas múltiples, además, la limpieza del tercio apical fue similar en los 3 diferentes sistemas de instrumentación. Los sistemas de lima única son igual de efectivos para reducir la carga microbiana comparados con los sistemas de limas múltiples.

Use of a Cellulase from Trichoderma reesei as an Adjuvant for Enterococcus faecalis Biofilm Disruption in Combination with Antibiotics as an Alternative Treatment in Secondary Endodontic Infection.

Apical periodontitis is an inflammation leading to the injury and destruction of periradicular tissues. It is a sequence of events that starts from root canal infection, endodontic treatment, caries, or other dental interventions. Enterococcus faecalis is a ubiquitous oral pathogen that is challenging to eradicate because of biofilm formation during tooth infection. This study evaluated a hydrolase (CEL) from the fungus Trichoderma reesei combined with amoxicillin/clavulanic acid as a treatment against a clinical E. faecalis strain. Electron microscopy was used to visualize the structure modification of the extracellular polymeric substances. Biofilms were developed on human dental apices using standardized bioreactors to evaluate the antibiofilm activity of the treatment. Calcein and ethidium homodimer assays were used to evaluate the cytotoxic activity in human fibroblasts. In contrast, the human-derived monocytic cell line (THP-1) was used to evaluate the immunological response of CEL. In addition, the secretion of the pro-inflammatory cytokines IL-6 and TNF-α and the anti-inflammatory cytokine IL-10 were measured by ELISA. The results demonstrated that CEL did not induce the secretion of IL-6 and TNF-α when compared with lipopolysaccharide used as a positive control. Furthermore, the treatment combining CEL with amoxicillin/clavulanic acid showed excellent antibiofilm activity, with a 91.4% reduction in CFU on apical biofilms and a 97.6% reduction in the microcolonies. The results of this study could be used to develop a treatment to help eradicate persistent E. faecalis in apical periodontitis.

Correlation between bacterial type/bacterial quantity and bone loss detected by cone beam computed tomography (CBCT) in primary endodontic infections / Correlación entre el tipo y cantidad de bacterias y la pérdida ósea detectada por Tomografía Computarizada de Haz Cónico (CBCT) en infecciones endodóncicas primarias

Abstract Periapical lesions (PL) of endodontic origin are one of the most common pathological conditions that affect peri-radicular tissues. The main objective of this study was to evaluate the amount and species of microorganisms isolated from necrotic pulps, establish a correlation between these and the size of periapical lesions, and how the amount and species of microorganisms decreased with non-surgical root canal treatment. Twenty-seven patients with a clinical diagnosis of dental pulp necrosis and chronic periapical lesions were selected; a Cone Beam Computed Tomography (CBCT) and microbial samples of the root canal system were taken previous to a disinfection protocol, a post-instrumentation/ disinfection protocol, and a post-medication placement. Samples were processed for colony-forming unit (CFU) counting, Gram staining technique, and bacterial identification by the API-20 Strep/API-20A system. The API system identified 21 species of microorganisms in the pre-instrumentation samples, 11 species in the post-instrumentation samples, and 11 in the post-medication samples. There was a correlation coefficient of 0.598% between the initial size of the lesion and the number of bacteria, with a coefficient of determination up to 35.7%, a correlation coefficient of 0.486% and a determination coefficient of 23.6% between the size of the periapical lesion and the number of CFUs. This study contributes to the knowledge of the amount and species of microorganisms isolated and identified from necrotic pulps, establishes a correlation between the amount and species of microorganisms and the size of the periapical lesions, and shows how the decrease of microorganisms contributes to the healing of PL, corroborating the importance of an adequate disinfection protocol.

Resumen Las lesiones periapicales (LP) de origen endodóncico son la condición patológica más común que afectan los tejidos perirradiculares. El objetivo principal de este estudio es evaluar la cantidad y especie de bacterias aisladas de pulpas necróticas, correlacionar la cantidad y especies bacterianas con el tamaño de la lesión, y cómo disminuyen la cantidad y especies de microorganismos con el tratamiento de conductos. A 27 pacientes con diagnóstico de necrosis pulpar y lesión periapical crónica detectada con CBCT se les tomaron muestras microbianas del sistema de conductos antes y después del protocolo de desinfección y de la medicación intraconducto. Las muestras se procesaron para el recuento de unidades de formación de colonias (UFC), tinción de Gram e identificación mediante el sistema API-20 Strep/API-20A. Se identificaron 21 especies en las muestras pre-instrumentación, 11 en las muestras post-instrumentación y 11 en las muestras post-medicación; se observó un coeficiente de correlación del 0,598% entre el tamaño inicial de la lesión y la cantidad de bacterias, con un coeficiente de determinación hasta el 35,7%, un coeficiente de correlación del 0,486% y un coeficiente de determinación del 23,6% entre el tamaño de la lesión periapical y el número de UFCs. Este estudio contribuye al conocimiento sobre la cantidad y especies de microorganismos aislados e identificados a partir de pulpas necróticas, establece una correlación entre la cantidad y especies de microorganismos y el tamaño de las lesiones periapicales y exhibe cómo la disminución de microorganismos contribuye a la curación de LP, corroborando la importancia de un adecuado protocolo de desinfección.

MTA-Based Cements: Biocompatibility and Effects on the Gene Expression of Collagen Type 1 and TGF-ß1.

Objective: This study sought to evaluate the biocompatibility of Neomineral Trioxide Aggregate (Neo-MTA), MTA Repair High Plasticity (MTA-HP), and Mineral Trioxide Aggregate-Angelus white (MTA-Ang) in fibroblasts of human dental pulp. Materials and Methods: Morphology was evaluated after 24 h of incubation. LIVE/DEAD assay and cell adhesion tests were performed at 24 h of treatment. Cell proliferation assays (MTSs) and Annexin V were performed at 48 h incubation with different treatments. The expression of Col-1 and TGF-ß1 was tested by endpoint PCR at 5 days of treatment. Results: Morphological changes were observed in all groups. Neo-MTA and MTA-Ang were associated with increased cell viability, and all materials induced apoptosis, with a higher percentage in the MTA-HP group than in the other groups. In the LIVE/DEAD assay, there was more damage to the cell membrane in the group of cells treated with MTA-HP than in the other groups. Conclusion: Neo-MTA and MTA-Ang presented similar biocompatibility, and both showed greater biocompatibility than MTA-HP. MTA-HP and MTA-Ang increased Col-1A gene expression, and Neo-MTA and MTA-Ang increased TGF-ß1 gene expression in a similar way.

Root canal microorganisms and their antibiotic susceptibility in patients with persistent endodontic infections, with and without clinical symptoms.

Secondary/persistent infections are present in teeth with previous root canal treatment, and a great variety of anaerobic microorganisms has been observed in these infections. The antibiotics prescription is occasional; however, in some cases, it is essential, particularly when the general health condition of the patient is compromised. The aims of this study were to identify the associated microorganisms in diagnosis of persistent or secondary apical periodontitis and to evaluate the susceptibility level to the antibiotics most used. Fifteen patients with persistent or secondary apical periodontitis requiring endodontic re-treatment were included. Microbiological samples were taken from the root canals and incubated in thioglycollate under anaerobic conditions. Anaerobic CDC agar (formulated by the Center for Disease Control and Prevention) was employed as a culture medium and the microorganisms were identified using the API system. The microorganisms were subjected to antibiograms with three different antibiotics. Twenty-six microorganisms were identified, the most common genus was Enterococcus (26.8%), Streptococcus (19.22%), Aerococcus (19.1%), and Clostridium (11.4%). 48% of them were susceptible to amoxicillin, with 28% of resistance. For clavulanic acid/amoxicillin, the susceptibility occurred in 32%, with 28% of resistance; and for clindamycin, the susceptibility was present in 40%, with 52% of resistance. The most frequently detected associated microorganism for secondary infections was genus Enterococcus, which exhibited high resistance to the studied antibiotics.

Evaluation of Apical Transportation by Three Rotary Systems in Extracted Teeth with Curved Canals / Evaluación de la transportación apical con tres sistemas rotatorios en dientes extraídos con conductos curvos

Abstract The aim of this study was to compare the apical transportation in extracted teeth using three different rotary nickel-titanium systems (Mtwo, Hyflex CM, and Typhoon). Sixty extracted first molars were randomly divided into three groups (n=20 in each group) with similar root canal curvatures (25-52 degrees). All root canals were prepared to size 30 using a crown-down preparation technique for each rotary system. Loss of working length and apical transportation were determined by X-ray evaluation. Comparisons between the groups were performed using one-way analysis of variance (ANOVA) or Kruskal-Wallis tests, and the post hoc analyses employed were Dunn´s or Tukey´s multiple comparison tests. No significant differences were detected between the different rotary systems in the loss of working length and apical transportation. This in vitro study showed that the use of these three rotary systems are safe and useful for instrumentation in curved canals; however, further in vivo research is essential to compare the effectiveness and safety of these systems for use in curved canals.

Resumen El objetivo del presente estudio fue comparar la transportación apical en dientes extraídos utilizando tres sistemas rotatorios de níquel-titanio (Mtwo, Hyflex CM y Typhoon). Sesenta primeros molares extraídos se dividieron aleatoriamente en tres grupos (n=20 en cada grupo) con curvaturas del conducto radicular similares (25-52 grados). Todos los conductos radiculares se prepararon usando una técnica corono apical para cada sistema rotatorio. La pérdida de la longitud de trabajo y la transportación apical se determinaron mediante evaluación radiográfica. Las comparaciones entre los grupos se realizaron utilizando análisis de varianza de una vía (ANOVA) o Kruskal-Wallis, y los análisis post hoc empleados fueron las pruebas de comparación múltiple de Dunn o Tukey. No se detectaron diferencias significativas entre los diferentes sistemas rotatorios en la pérdida de la longitud de trabajo y transportación apical. Este estudio demostró que el uso de estos tres sistemas es seguro y útil para su instrumentación en conductos curvos; sin embargo, investigación in vivo es necesaria para comparar la efectividad y seguridad de estos sistemas para su uso en conductos curvos.

Evaluation of in vitro biofilm elimination of Enterococcus faecalis using a continuous ultrasonic irrigation device.

This study sought to evaluate biofilm elimination using the HBW Ultrasonic Ring based on continuous ultrasonic irrigation. Forty-five premolars and molars with complex curvatures were included. An Enterococcus faecalis biofilm was established for 30 days on the extracted teeth. The teeth were then stratified into three experimental groups for instrumentation and irrigation (i.e. HBW Ultrasonic Ring, conventional irrigation, and passive ultrasonic irrigation). Pre- and post-instrumentation samples were collected, and reductions of bacterial load were evaluated by McFarland's scale, counting of colony-forming units, and scanning electronic microscopy. The HBW Ultrasonic Ring promoted a higher reduction in bacterial load relative to conventional irrigation (P < 0.05) and a similar reduction compared with passive ultrasonic irrigation (P > 0.05). These results suggest the HBW Ultrasonic Ring is a promising alternative modality for simultaneous instrumentation and irrigation during root canal treatment, achieving an appropriate level of bacterial reduction and allowing the passage of the irrigating solution throughout the entire working length.

Elimination of an intraradicular biofilm composed of enterococcus faecalis and candida albicans using a negative apical pressure irrigation system / Eliminación de una biopelícula intraradicular compuesta por enterococcus faecalis y candida albicans utilizando un sistema de irrigación de presión apical negativa

Endodontic treatment consists of the cleaning and disinfecting the root canal system, which is achieved using adequate mechanical instru-mentation and chemical irrigation. Endodontic microorganisms are present in root canals in the form of a biofilm, and their elimination ensures the success of endodontic treatment. Irrigation is a key factor contributing to the elimination of this intraconduct biofilm, and different irrigator agents and irrigation techniques, such as irrigation with negative apical pressure, a novel automated irrigation mechanism based on suction intraconduct, have been used. In this study, we evaluated the ability of a negative apical pressure system with different concentrations of sodium hypochlorite and durations to reduce the microbial load. Materials and Methods: An intraradicular biofilm composed of Enterococcus faecalis and Candida albicans was generated during twenty-one days of static culture on one hundred mesio-vestibular roots of upper molars with complex curvatures greater than 30°C, and the roots were classified in six groups with different concentrations and contact times of sodium hypochlorite. Subsequently, the reduction in the microbial load was measured with McFarland scale and the enumeration of colony forming units and was evaluated with scanning electronic microscopy. Results: We observed a significant difference in the reduction of the microbial load prior to instrumentation compared with postinstrumentation between the groups treated with 2.25% and 5.25% NaOCl for 30, 60 and 90 seconds of contact time (p<0.05), but we did not observe differences in the reduction of microbial load between different contact times and concentrations of sodium hypochlorite employed (p>0.05). Conclusion: Negative apical pressure is a good option for irrigation in endodontics, as it allows the passage of the irrigation fluid along the total length of the root canal and produces a better antimicrobial effect.

El tratamiento de endodoncia consiste en la limpieza y desinfección del sistema de conducto radicular, lo que se logra utilizando instrumentación mecánica adecuada y riego químico. Los microorganismos endodónticos están presentes en los conductos radiculares en forma de una biopelícula, y su eliminación asegura el éxito del tratamiento endodóntico. La irrigación es un factor clave que contribuye a la eliminación de esta biopelícula intraconductora, y se han utilizado diferentes agentes irrigadores y técnicas de irrigación, como la irrigación con presión apical negativa, un nuevo mecanismo automatizado de irrigación basado en la intraconducción de succión. En este estudio, evaluamos la capacidad de un sistema de presión apical negativa con diferentes concentraciones de hipoclorito de sodio y duraciones para reducir la carga microbiana. Material y Métodos: Se generó una biopelícula intraradicular compuesta por Enterococcus faecalisy Candida albicans durante veintiún días de cultivo estático en cien raíces mesio-vestibulares de molares superiores con curvaturas complejas superiores a 30°C, y las raíces se clasificaron en seis grupos con diferentes concentraciones y tiempos de contacto de hipoclorito de sodio. Posteriormente, la reducción en la carga microbiana se midió con la escala de McFarland y la enumeración de las unidades formadoras de colonias y se evaluó con microscopía electrónica de barrido. Resultado: Observamos una diferencia significativa en la reducción de la carga microbiana antes de la instrumentación en comparación con la postinstrumentación entre los grupos tratados con NaOCl 2.25% y 5.25% durante 30, 60 y 90 segundos de tiempo de contacto (p<0.05), pero lo hicimos No se observan diferencias en la reducción de la carga microbiana entre los diferentes tiempos de contacto y las concentraciones de hipoclorito de sodio empleado (p>0.05). Conclusión:La presión apical negativa es una buena opción para el riego en endodoncia, ya que permite el paso del líquido de riego a lo largo de todo el conducto radicular y produce un mejor efecto antimicrobiano.

Aerobic and anaerobic microorganisms and antibiotic sensitivity of odontogenic maxillofacial infections.

This study aimed to identify the aerobic and anaerobic causal microorganisms of odontogenic infections and their antibiotic sensitivity. Purulent exudates were taken from patients with odontogenic infections by transdermal puncture, and aerobic and anaerobic microorganisms were identified using biochemical tests. Susceptibility to antibiotics was tested using the Kirby-Bauer method; the inhibition halos were measured according to NCCLS, and based on the results, the microorganisms were classified as susceptible, intermediate or resistant to each antibiotic. Frequencies of species and percentages of resistance were calculated. The microorganisms associated with odontogenic infections were principally anaerobic (65.3% anaerobic vs. 35.7% aerobic), and the susceptibility to antibiotics was higher in anaerobic than in aerobic microorganisms. The majority of isolated microorganisms (82%) showed susceptibility to amoxicillin/clavulanic acid. The causal agents of odontogenic infections were anaerobic microorganisms, which exhibited high resistance to antibiotics.

Cytotoxicity, Cell Adhesion, and Apoptotic Gene Expression in Periodontal Ligament Fibroblasts treated with Endodontic Sealers.

OBJECTIVE: The present study assessed cytotoxicity, cell adhesion, and apoptotic gene expression in periodontal ligament fibroblasts (PLF) treated with 2 endodontic sealers. METHODS: PLF cells were obtained from nonerupted third molars and cultured. MTS and LIVE/DEAD assays were performed using different treatments and time periods. Cellular adhesion was evaluated using immunocytochemistry for integrin ß1 and vinculin expression, and the gene expressions of nuclear factor kB (NF-кB), P53, and apoptotic protease-activating factor 1 (Apaf-1) were evaluated using PCR. RESULTS: Cell proliferation at 12, 24, and 48 h was statistically significant in the control and PLF groups receiving different treatments; PLF treated with culture medium containing non-hardened (NH) sealers showed a decrease in the number of cells. PLF treated with culture medium containing hardened (H) sealers also exhibited a decreased cell population. Integrin ß1 and vinculin were expressed in both cell cultures treated with Acroseal (NH and H); however, the cell morphology changed and the cell population decreased. The gene expression of NF-kB and that of P53 were significantly different between the control group and the groups treated with the different sealers; mineral trioxide aggregate (MTA) (NH and H) inhibited Apaf-1, and PLF treated with Acroseal H exhibited increased Apaf-1 expression. CONCLUSION: Both sealers showed a certain level of cytotoxicity. The gene expression of NF-κB and P53 in PLF treated with the sealers showed significant changes compared to that of the control group, and MTA inhibited Apaf-1.

Frecuencia de Candida en conductos radiculares de dientes con infección endodóntica primaria y persistente / Frequency of Candida in root canals of teeth with primary and persistent endodontic infections

Antecedentes: La identificación microbiológica en infecciones endodónticas se ha enfocado principalmente a la caracterización bacteriana sin dar relevancia a las levaduras que, por sus factores de virulencia, pueden afectar el resultado del tratamiento clínico realizado. Objetivos: Determinar la frecuencia de Candida en condiciones anaerobias en conductos radiculares con infecciones endodónticas primarias y persistentes, y evaluar un método de muestreo microbiológico por lavado y aspiración en comparación con el método tradicional por absorción con puntas de papel. Métodos: Se tomaron 50 muestras microbiológicas de dientes con infección endodóntica primaria y persistente provenientes de 47 pacientes que requirieron tratamiento endodóntico. Se emplearon dos métodos de toma de muestra microbiológica: un método por aspiración y un método por absorción con puntas de papel, ambos con dos tipos de caldo de cultivo (M1-M4). Las muestras fueron cultivadas en condiciones de anaerobiosis hasta lograr una turbidez de 0,5 en la escala de McFarland, y se resembraron en placas de agar dextrosa Sabouraud y agar sangre enriquecido para anaerobios. Se realizó una observación macroscópica y microscópica de las colonias formadas. Las pruebas de producción de tubo germinal, crecimiento en CHROMagar e identificación bioquímica se realizaron a los aislamientos levaduriformes obtenidos. Resultados: De los 50 dientes evaluados, 18 de ellos (36%) mostraron infección por levaduras. En los casos de infección primaria se encontraron levaduras en 15 de 36 dientes (41,6%) y en casos de infección persistente en 3 de 14 (21,4%). El método por lavado y aspiración con caldo de dextrosa Sabouraud recuperó mayor diversidad de especies. Conclusiones: La frecuencia de levaduras fue más alta en los dientes con infección primaria en comparación con los dientes con infección persistente. La especie de levadura predominante fue Candida albicans. El método de toma de muestra por lavado y aspiración fue más eficiente en la recuperación de aislamientos de Candida que el método tradicional por absorción con puntas de papel

Background: Microbiological identification in endodontic infections has focused mainly on bacteria without giving much attention to yeasts, which, due to their virulence factors, can affect the outcomes of root canal treatment. Aims: To determine the frequency of Candida in anaerobic conditions in root canals with primary and persistent endodontic infection, as well as to evaluate a microbiological sampling method using aspiration compared to the traditional absorption method with paper points. Methods: Fifty microbiological samples were obtained from teeth of 47 patients requiring endodontic treatments, due to either primary or persistent infections. Two microbiological sampling methods were used: an aspiration method, and the traditional paper point absorption method. In each of these methods, two types of medium were used (M1-M4). Samples were cultured under anaerobic conditions until reaching 0.5 McFarland turbidity, and then inoculated on Sabouraud dextrose, as well as on anaerobic enriched blood agar plates. Macroscopic and microscopic observations of the colonies were performed. The germ-tube test, growth on CHROMagar, and biochemical identification were performed on the isolated yeasts. Results: Fungal infection was found in 18 (36%) samples out of the 50 teeth evaluated. In the 18 samples positive for fungal infection, 15 out of 36 (41.6%) teeth were taken from a primary infection, and 3 out of 14 (21.4%) from a persistent infection. The aspiration method using Sabouraud dextrose medium recovered a greater diversity of species. Conclusions: Yeasts frequency was higher in teeth with primary infections compared to teeth with persistent infections. The predominant yeast species was Candida albicans. The aspirating sampling method was more efficient in the recovery of Candida isolates than the traditional absorption method

[Frequency of Candida in root canals of teeth with primary and persistent endodontic infections]. / Frecuencia de Candida en conductos radiculares de dientes con infección endodóntica primaria y persistente.

BACKGROUND: Microbiological identification in endodontic infections has focused mainly on bacteria without giving much attention to yeasts, which, due to their virulence factors, can affect the outcomes of root canal treatment. AIMS: To determine the frequency of Candida in anaerobic conditions in root canals with primary and persistent endodontic infection, as well as to evaluate a microbiological sampling method using aspiration compared to the traditional absorption method with paper points. METHODS: Fifty microbiological samples were obtained from teeth of 47 patients requiring endodontic treatments, due to either primary or persistent infections. Two microbiological sampling methods were used: an aspiration method, and the traditional paper point absorption method. In each of these methods, two types of medium were used (M1-M4). Samples were cultured under anaerobic conditions until reaching 0.5 McFarland turbidity, and then inoculated on Sabouraud dextrose, as well as on anaerobic enriched blood agar plates. Macroscopic and microscopic observations of the colonies were performed. The germ-tube test, growth on CHROMagar, and biochemical identification were performed on the isolated yeasts. RESULTS: Fungal infection was found in 18 (36%) samples out of the 50 teeth evaluated. In the 18 samples positive for fungal infection, 15 out of 36 (41.6%) teeth were taken from a primary infection, and 3 out of 14 (21.4%) from a persistent infection. The aspiration method using Sabouraud dextrose medium recovered a greater diversity of species. CONCLUSIONS: Yeasts frequency was higher in teeth with primary infections compared to teeth with persistent infections. The predominant yeast species was Candida albicans. The aspirating sampling method was more efficient in the recovery of Candida isolates than the traditional absorption method.

Eficacia antimicrobiana del primer ortodóncico adicionado con nanopartículas de plata: Estudio transversal in vitro / Antimicrobial efficacy of orthodontic primer added with silver nanoparticles: Cross-sectional in vitro study

Se evaluó la eficacia antimicrobiana de las nanopartículas de plata (NPsAg) incorporadas al adhesivo (primer) colocado en el esmalte dental adyacente a la aparatología ortodóncica fija (brackets). Se realizó un estudio experimental in vitro en 40 premolares, los cuales se dividieron en dos grupos con brackets, uno cementado con primer convencional y otro adicionado con NPsAg; se colocaron en medios de cultivo, previamente inoculados con Streptococcus mutans, y se tomaron muestras para hacer cultivos y conteo de unidades formadoras de colonias (UFC) al día 1, 15 y 30. Se observó una disminución de la presencia de Streptococcus mutans en las muestras a los 15 días de colocado el primer con la agregación de nanopartículas, aunque tal efecto se redujo a los 30 días. Esta reducción del efecto de las nanopartículas puede deberse a la inexistencia de limpieza mecánica, lo cual favoreció la agregación bacteriana sobre el biofilm, afectando su efecto antimicrobiano. Esto sugiere la necesidad de realizar estudios in vivo que permitan observar el comportamiento de los biomateriales en el medio bucal. Las NPsAg agregadas al primer resultan una herramienta eficaz para prevenir la desmineralización del esmalte alrededor de la aparatología ortodóncica fija.

The antimicrobial efficacy of the silver nanoparticles (NPsAg), incorporated into the adhesive (primer) placed in the enamel adjacent to fixed orthodontic appliances (brackets), was evaluated. An experimental study was performed on 40 premolars in vitro, which were divided into two groups with brackets, one cemented with conventional primer and another added with NPsAg, placed in culture media previously inoculated with Streptococcus mutans, and sampled for culturing and counting colony forming units (UFC) on days 1, 15 and 30. A decrease in the presence of Streptococcus mutans in the samples after 15 days with nanoparticle aggregation was observed, and a reduction in the effect of said nanoparticles after 30 days. This reduction of the nanoparticles effects can be due to the absence of mechanical cleaning, which favored the bacterial aggregation on the biofilm, affecting its antimicrobial effect. This suggest the need for realizing studies in “vivo” which will allow the observation of the behavior of the biometals on the buccal medium. The NPsAg added to the primer are an effective tool to prevent the demineralization of the enamel around the fixed orthodontic appliances.

Antimicrobial efficacy of orthodontic primer added with silver nanoparticles. Cross-sectional in vitro study. / Eficacia antimicrobiana del primer ortodóncico adicionado con nanopartículas de plata. Estudio transversal in vitro.

The antimicrobial efficacy of the silver nanoparticles (NPsAg), incorporated into the adhesive (primer) placed in the enamel adjacent to fixed orthodontic appliances (brackets), was evaluated. An experimental study was performed on 40 premolars in vitro, which were divided into two groups with brackets, one cemented with conventional primer and another added with NPsAg, placed in culture media previously inoculated with Streptococcus mutans, and sampled for culturing and counting colony forming units (UFC) on days 1, 15 and 30. A decrease in the presence of Streptococcus mutans in the samples after 15 days with nanoparticle aggregation was observed, and a reduction in the effect of said nanoparticles after 30 days. This reduction of the nanoparticles effects can be due to the absence of mechanical cleaning, which favored the bacterial aggregation on the biofilm, affecting its antimicrobial effect. This suggest the need for realizing studies in "vivo" which will allow the observation of the behavior of the biometals on the buccal medium. The NPsAg added to the primer are an effective tool to prevent the demineralization of the enamel around the fixed orthodontic appliances.

Moxifloxacin versus Clindamycin/Ceftriaxone in the management of odontogenic maxillofacial infectious processes: A preliminary, intrahospital, controlled clinical trial.

BACKGROUND: The aim of this study was to compare the days of hospitalization length between patients treated with Moxifloxacin with that of patients treated with a Clindamycin/Ceftriaxone combination and additionally, to isolate and identify the oral pathogens involved in orofacial odontogenic infections. MATERIAL AND METHODS: A pilot-controlled-clinical-trial was carried out on hospitalized patients with cervicofacial odontogenic abscesses or cellulitis, who were randomly asigned to two study groups: 1) patients who received Moxifloxacin, and 2) patients receiving Clindamycin/Ceftriaxone combination. Infiltrate samples were collected through transdermic or transmucosal punction and later cultured on a media specific for aerobic and anaerobic microorganisms. Mean hospitalization duration in days until hospital discharge and susceptibility assessment in rates were established. RESULTS: Mean hospitalization time in days of patients treated with Moxifloxacin was 7.0 ± 1.6 days, while in the Clindamycin/Ceftriaxone group, this was 8.4 ± 1.8 days, although significant difference could not be demonstrated (p=0.074). A total of 43 strains were isolated, all of these Gram-positive. These strains appeared to be highly sensitive to Moxifloxacin (97.5%) and Ceftriaxone (92.5%). CONCLUSIONS: Moxifloxacin and Ceftriaxone appear to be potential convenient and rational alternatives to traditional antibiotics, for treating severe odontogenic infections, in conjunction with surgical extraoral incision, debridement, and drainage. KEY WORDS: Orofacial odontogenic infections, antimicrobial susceptibility, antimicrobial resistance.

Efecto antimicrobiano de una solución de superoxidación con pH neutro para desinfección de cavidades clase I / Effectiveness of a neutral pH super-oxidized solution for antimicrobial disinfection of class I cavities

Objetivo: determinar la disminución de la carga bacteriana en dentina de cavidades clase I posterior a la aplicación de clorhexidina 2 por ciento en comparación con la aplicación de solución de superoxidación con pH neutro. Material y métodos: Se realizó un estudio transversal clínico, a 30 pacientes en el Área de Clínicas de la Facultad de Estomatología en la Universidad Autónoma de San Luis Potosí, de los cuales se obtuvieron 60 muestras en cavidades clase I en primeros y segundos molares inferiores permanentes, previas al tratamiento y 60 posteriores que se dividieron en tres grupos, grupo control (n = 20), grupo A correspondiente a clorhexidina al 2 por ciento (n = 20) y grupo B correspondiente a solución de superoxidación con pH neutro (n = 20), posteriormente las muestras fueron llevadas al laboratorio donde se realizó una dilución seriada, para posteriormente sembrar las muestras en placas de agar soya tripticaseina y hacer el conteo de UFC después de haber sido incubadas 24 horas. Resultados: Se realizó una comparación de todos los grupos en cuanto a la disminución de carga bacteriana pretratamiento y postratamiento. Se observó diferencia es tadística significativa en el grupo tratado con clorhexidina al 2 por ciento (p < 0.01) mientras que en los grupos tratados con agua destilada y solución de superoxidación con pH neutro no fueron significativas, ambas con una (p > 0.05) entre las muestras pretratamiento y postratamiento. Conclusiones: Se logró obtener muestras en primeros y segundos molares inferiores en las que se cuantificaron microorganismos previos y posteriores al tratamiento mediante la cuantificación de UFC. Se encontraron diferencias significativas entre grupos, por lo que podemos decir de acuerdo con nuestros resultados que la clorhexidina al 2 por ciento tiene mayor efecto antimicrobiano en la desinfección de cavidades clase I que la solución de superoxidación con pH neutro.

background: Dental caries is a disease characterized by demineralization of the hard tissues of the tooth. If left untreated, it leads to cavitation, discomfort, pain, and the eventual loss of the tooth. A range of antiseptics have been used to eliminate microorganisms from cavities, one of the most common being chlorhexidine, due to the advantages it offers. Nowadays there are products available that offer not only the same microbicidal capacity, but also a greater half-life and superior tissue compatibility. One new option for cavity disinfection is pH neutral super-oxidation solution. Objective: To determine the decrease in bacterial load in the dentin of class I cavities following the application of 2% chlorhexidine compared to a neutral pH over-super-oxidized solution. Material and methods:A clinical cross-sectional study was conducted involving a total of 30 patients at the Faculty of Stomatology Clinics of the Autonomous University of San Luis Potosí, from whom 60 samples were obtained from class I cavities in first and second permanent lower molars prior to treatment and 60 following...

Risk factors and biofilm detection on central venous catheters of patients attended at tertiary hospital.

AIM: To determinate the significance of risk factors with the presence of biofilm on catheters of patients attended at tertiary hospital cares. MATERIAL AND METHODS: A total of 126 patients were included, data collection by observing the handling of the CVC, clinical history and microbiological isolation methods of CVCs tips (Roll-plate, sonication and scanning electron microscopy) were evaluated. RESULTS: Certain factors, such as the lack of proper hand washing, the use of primary barriers and preparing medications in the same hospital service, showed an important relationship between biofilm formation in CVCs. The sonication method presented that most of the samples had isolation of multispecies 29 samples (64%); in contrast with the roll-plate method, just one sample (3%) was isolated. CONCLUSIONS: The importance of the strict aseptic techniques of insertion and of the handlings of CVC was highlighted, the failure of both techniques was related to the biofilm formation and was evidenced using the scanning electron microscopy. Since this tool is not available in most hospitals, we present the correlation of those evidences with other standard microbiological methods and risk factors, which are necessary for the sensible detection of the different steps of the biofilm formation on CVC and their correct interpretation with clinical evidences.

Identification of cultivable microorganisms from primary teeth with necrotic pulps.

The objective of this study was to identify cultivable microorganisms from primary teeth with necrotic pulps. This experimental study included 21 patients of both sexes between 4 and 7 years of age with necrotic pulps in primary teeth. Twenty-one maxillary and mandibular molars containing at least 1 necrotic canal, an abscess or sinus tract, one or more radiolucent areas in the furcation or periapical region, teeth having at least two thirds of root length, and carious lesions directly exposed to the oral environment were included. After antisepsis of the oral cavity, anesthesia of the affected tooth, and isolation and disinfection of the operative field, 3 sterile absorbent paper points were sequentially placed for 30 seconds for the collection of samples. The samples were immediately processed in an anaerobic chamber, and all isolated microorganisms were identified. Anaerobic species (anaerobic facultative and moderate anaerobes) were isolated in all root canals; 68.4% of root canal samples studied showed a polymicrobial nature. Most of the isolate consisted of Bifidobacterium Spp2 and Streptococcus intermedius. Other less frequently encountered species were Actinomyces israelii, Bifidobacterium spp 1, Clostridium spp, and Candida albicans. Results indicate the existence of combinations of bacterial species in root canal infections of the primary dentition with necrotic pulps, anaerobic bacteria predominating.