Effect of a calcium hydroxide-based intracanal medicament containing N-2-methyl pyrrolidone as a vehicle against Enterococcus faecalis biofilm

Abstract This study investigated the effect of a calcium hydroxide (CH) paste (CleaniCal®) containing N-2-methyl pyrrolidone (NMP) as a vehicle on Enterococcus faecalis (E. faecalis) biofilms compared with other products containing saline (Calasept Plus™) or propylene glycol (PG) (Calcipex II®). Methodology Standardized bovine root canal specimens were used. The antibacterial effects were measured by colony-forming unit counting. The thickness of bacterial microcolonies and exopolysaccharides was assessed using confocal laser scanning microscopy. Morphological features of the biofilms were observed using field-emission scanning electron microscopy (FE-SEM). Bovine tooth blocks covered with nail polish were immersed into the vehicles and dispelling was observed. The data were analyzed using one-way analysis of variance and Tukey tests (p<0.05). Results CleaniCal® showed the highest antibacterial activity, followed by Calcipex II® (p<0.05). Moreover, NMP showed a higher antibacterial effect compared with PG (p<0.05). The thickness of bacteria and EPS in the CleaniCal® group was significantly lower than that of other materials tested (p<0.05). FE-SEM images showed the specimens treated with Calasept Plus™ were covered with biofilms, whereas the specimens treated with other medicaments were not. Notably, the specimen treated with CleaniCal® was cleaner than the one treated with Calcipex II®. Furthermore, the nail polish on the bovine tooth block immersed in NMP was completely dispelled. Conclusions CleaniCal® performed better than Calasept Plus™ and Calcipex II® in the removal efficacy of E. faecalis biofilms. The results suggest the effect might be due to the potent dissolving effect of NMP on organic substances.

In vitro antimicrobial efficiency of a mouthwash containing triclosan/gantrez and sodium bicarbonate

Several antiseptic substances have been used as adjuncts to routine mechanical procedures of oral hygiene, based on their antimicrobial effects. The objective of this study was to assess in vitro the antimicrobial efficiency of a mouthwash containing Triclosan/Gantrez and sodium bicarbonate in comparison to both positive and negative controls. Standard strain samples of Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus and Bacillus subtilis were used. Samples of Streptococcus mutans and Gram-negative bacilli were collected from 20 volunteers (10 with a clinically healthy periodontium and 10 presenting biofilm-associated gingivitis). Evaluation of the antimicrobial activity was performed by determining the minimal inhibitory concentration (MIC). The results indicated that the test solution inhibited the growth of both Gram-negative and Gram-positive microorganisms from the volunteers’ saliva as well as that of the standard strains at the MIC dilution of 1:20, whereas the MIC dilution of 0.12 percent chlorhexidine against the same bacteria was 1:80. Thus, even though the tested mouthrinse solution presented an in-vitro antimicrobial activity superior to that of a placebo, it was inferior to that of chlorhexidine.

Diversas substâncias antisépticas têm sido utilizadas como adjuntos aos procedimentos mecânicos rotineiros de higiene oral, com base em seus efeitos antimicrobianos. O objetivo deste estudo foi avaliar, in vitro, a eficiência antimicrobiana de um enxaguatório bucal contendo Triclosan/Gantrez e bicarbonato de sódio, em comparação a controles positivos e negativos. Linhagens padrão de Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus e Bacillus subtilis foram utilizadas. Amostras de Streptococcus mutans e Bacilos Gram-negativos foram coletadas de 20 voluntários (10 com um periodonto clinicamente saudável e 10 com gengivite associada à presença de biofilme). A avaliação da atividade antimicrobiana foi realizada pela determinação da Concentração Inibitória Mínima (CIM). Os resultados mostraram que a solução teste inibiu o crescimento de microrganismos Gram-negativos e Gram-positivos da saliva dos voluntários, bem como das linhagens padrão na CIM de 1:20, enquanto que a CIM da diluição de clorexidina 0.12 por cento contra as mesmas bactérias foi de 1:80. Desta forma, apesar de o enxaguatório bucal testado apresentar atividade antimicrobiana in vitro superior à do placebo, esta foi inferior à da Clorexidina.

An Experimental Animal Model of Fulminant Hepatic Failure in Pigs

The objective of this study was to develop an experimental animal model of fulminant hepatic failure to test the efficacy of the bioartificial liver system. The portal vein and the hepatic artery were clamped intermittently and then the hepatic artery was ligated (ligation group, n=5). Pigs whose hepatic arteries were not ligated after clamping were assigned to the non-ligation group (n=5). The biochemical changes in blood, histologic alterations of the liver and neurologic examination for pigs were checked up. All animals died within 17 hr in the ligation group. On the other hand, all animals survived more than 7 days in the non-ligation group. In the ligation group, the levels of ammonia, lactic acid and creatinine showed a progressively increasing pattern. Prothrombin time was also prolonged gradually. Cytoplasmic condensation and nuclear pyknosis of hepatocytes were detected histologically at autopsy. Neurologic findings such as decreased pain sensation, tachypnea and no light reflex of pupils were observed. The findings shown in the ligation group are similar to the clinical features of fulminant hepatic failure in human and this animal model is reproducible. Therefore, this can be a suitable animal model to evaluate the efficacy of the bioartificial liver system for treating fulminant hepatic failure.

Efeito do jato profilático de bicarbonato de sódio sobre a superfície de materiais restauradores estéticos / The effect of the prophylactic jet on the surface of restorative materials

Foi avaliado, em Microscopia Eletrônica de Varredura, o efeito do jato profilático de bicarbonato de sódio sobre os materiais: Durafil, Z100, TPH, Concise, Heliomolar Chelon-fil e Dyract AP, com e sem a proteção do selante de superfície Fortify, por 15, 30 ou 60 segundos. Os autores concluíram que a aplicação do jato altera a superfície dos materiais. A partir de 30 segundos, todos os materiais tiveram o contorno alterado com perda de substância

Reanimación cardiopulmonar en pediatría / Cardiopulmonary resuscitation in pediatrics

La reanimación pediátrica (RP) ha experimentado avances, mejorando el conocimiento epidemiológico y fisiopatológico del paro en niños y de los efectos de procedimientos empleados para revertirlo. El paro cardiorrespiratorio en los niños suele ser un evento terminal, secundario a problemas respiratorios y habitualmente en asistolía. La entubación traqueal continúa siendo el método óptimo para asegurar una ventilación efectiva cuando el paro es atendido por personal experimentado. En la RP la utilidad de la toracotomía con masaje directo no ha sido comprobada y el procedimiento se considera peligroso. Después de asegurar la ventilación y el masaje cardíaco efectivos e ininterrumpidos, la prioridad es el rápido acceso venoso. Los equipos de RP deben emplear protocolos para lograr un acceso vascular. Si después de 3 intentos o 90'' no se obtiene una vía venosa, se deberá instalar una intraósea en menores de 6 años, en mayores se intentará cateterizar la vía femoral. Si no es posible, puede emplearse vía endotraqueal en pacientes entubados, recordando aumentar la dosis de adrenalina. Dada la gran letalidad del paro, fuera (90 a 97 por ciento) y dentro del hospital (69 a 95 por ciento), el mejor tratamiento es la prevención y detección precoz de los factores de riesgo. La adrenalina continúa siendo el fármaco de elección entre los empleados en el manejo del paro, por su capacidad para aumentar la presión de perfusión coronaria y cerebral, no habiendo sido superada por otras aminas naturales o sintéticas. Su dosis óptima parece ser mayor que lo establecido antes, recomendándose, en niños sin respuesta a una primera de 0,01 mg x kg, usar 0,1 a 0,2 mg x kg 3 a 5 min. después de la anterior. En el manejo de la acidosis, el empleo de alcalinizantes continúa siendo controvertido. El tratamiento más racional es conseguir ventilación pulmonar efectiva y perfusión tisular óptima con masaje y adrenalina. Atropina y calcio juegan roles menores en la RP y deben ser consideradas sólo en condiciones especiales. En el manejo de la fibrilación ventr y taquicardia ventricular sin pulso, la lidocaína y el bretilio son probablemente útiles y su empleo debe ser considerado en pacientes que no responden a la desfibrilación eléctrica. La adenosina constituye un nuevo medicamento antiarrítmico que ha probado ser efectivo y seguro en revertir la taquicardia supraventricular y debe ser incluido entre los nuevos medicamentos en RP