ABSTRACT The objective of the study was to describe the medical interns’ (MI) perceptions about the internship suspension during the COVID-19 quarantine in Peru. A cross-sectional descriptive study was conducted by means of a virtual survey regarding the perception of the internship suspension, return conditions and academic activities during quarantine. A total of 353 MIs participated in the study; 54.9% agreed or totally agreed with returning to their hospital sites if biosecurity measures were guaranteed, more than 90% felt uncertain about the restart and end dates, and 85.6% participated in academic virtual classes. It is concluded that the intention to return to the hospital increases when biosecurity measures are guaranteed. Hospitals should guarantee these measures and ensure health coverage for the MIs, if their return to hospitals is intended.

RESUMEN El objetivo del estudio fue describir las percepciones de los internos de medicina (IM) sobre la suspensión del internado durante la cuarentena por la COVID-19 en el Perú. Se realizó un estudio descriptivo transversal mediante una encuesta virtual sobre la percepción de la suspensión del internado, las condiciones de retorno y las actividades académicas durante la cuarentena. Participaron en el estudio 353IM, el 54,9% estuvo de acuerdo o totalmente de acuerdo con retornar a sus sedes hospitalarias si se garantizaban las medidas de bioseguridad; más del 90% sentía incertidumbre sobre la fecha de reinicio y el fin de internado, y el 85,6% participaba de clases virtuales académicas. Se concluye que la intención de volver al internado aumenta cuando se garantizan las medidas de bioseguridad. Las sedes hospitalarias deberían garantizar estas medidas y la cobertura de salud de los IM si se propone su retorno a los hospitales.

ABSTRACT The objective of the study was to describe the medical interns’ (MI) perceptions about the internship suspension during the COVID-19 quarantine in Peru. A cross-sectional descriptive study was conducted by means of a virtual survey regarding the perception of the internship suspension, return conditions and academic activities during quarantine. A total of 353 MIs participated in the study; 54.9% agreed or totally agreed with returning to their hospital sites if biosecurity measures were guaranteed, more than 90% felt uncertain about the restart and end dates, and 85.6% participated in academic virtual classes. It is concluded that the intention to return to the hospital increases when biosecurity measures are guaranteed. Hospitals should guarantee these measures and ensure health coverage for the MIs, if their return to hospitals is intended.

RESUMEN El objetivo del estudio fue describir las percepciones de los internos de medicina (IM) sobre la suspensión del internado durante la cuarentena por la COVID-19 en el Perú. Se realizó un estudio descriptivo transversal mediante una encuesta virtual sobre la percepción de la suspensión del internado, las condiciones de retorno y las actividades académicas durante la cuarentena. Participaron en el estudio 353IM, el 54,9% estuvo de acuerdo o totalmente de acuerdo con retornar a sus sedes hospitalarias si se garantizaban las medidas de bioseguridad; más del 90% sentía incertidumbre sobre la fecha de reinicio y el fin de internado, y el 85,6% participaba de clases virtuales académicas. Se concluye que la intención de volver al internado aumenta cuando se garantizan las medidas de bioseguridad. Las sedes hospitalarias deberían garantizar estas medidas y la cobertura de salud de los IM si se propone su retorno a los hospitales.

Objective: To describe the perception and uncertainty of medical interns (IM) about the medical internship, academic and extra-academic activities during this COVID-19 pandemic. Methods: Observational descriptive cross-sectional study. IM from Peruvian universities was contacted through the delegates of each university. A virtual survey was applied collecting sociodemographic data, position and uncertainty due to the suspension of the internship, situations of return or not to the internship, academic and extra-academic activities during the quarantine. Results: Data from 353 MI were analyzed, mean age of 25.2 years (standard deviation: 3.1 years), 72.8% had health insurance. 74.8% agreed with the removal of IM from their hospital based. 29.6% agreed or totally agreed with returning in case of collapse of the health system. However, 24.9% of IM would not return to their activities even with biosecurity measures and equipment. More than 90% of IM report feeling uncertainty regarding the restart date of the internship and of the National Medicine Exam (ENAM). 85.6% report using virtual media from ENAM preparation academies. Conclusions: The intention to return to the internship of the surveyed IM increased when the security measures were assured and at the end of the mandatory social immobilization. On the other hand, there is great uncertainty about the dates of return and completion of medical internship and ENAM. Moreover, the majority of respondents invest their time in non-formal education focusing on ENAM.  

Objetivo: Describir la percepción e incertidumbre de los internos de medicina (IM) sobre el internado médico, actividades académicas y extraacadémicas durante esta pandemia de COVID-19. Métodos: Estudio observacional descriptivo transversal. Se contactó a IM de universidades peruanas a través de sus respectivos delegados. Se aplicó una encuesta virtual durante la quinta semana de emergencia nacional. Se recolectó datos sociodemográficos, posición e incertidumbre por la suspensión del internado, situaciones de retorno o no, actividades académicas y extraacadémicas durante la cuarentena. Resultados: Se analizó datos de 353 IM, edad media de 25,2 años (desviación estándar: 3,1 años), 72,8% contaron con un seguro de salud. 74,8% estuvo de acuerdo con el retiro de los internos de sus sedes. 29,6% estuvo de acuerdo o totalmente de acuerdo con retornar en caso de colapso del sistema de salud. Sin embargo, 24,9% de los internos no retornarían a sus actividades aun con medidas y equipos de bioseguridad. Más del 90% de IM refieren sentir incertidumbre respecto a la fecha de reinicio del internado y del Examen Nacional de Medicina (ENAM). 85,6% reporta usar medios virtuales de academias de preparación ENAM. Conclusiones: La intención de volver al internado de los IM encuestados aumentaba cuando se aseguraban las medidas de seguridad y al finalizar la inmovilización social obligatoria. Por otro lado, existe una gran incertidumbre sobre las fechas de regreso y finalización de internado médico y del ENAM. Además, que la mayoría de los encuestados invierten su tiempo en educación no formal enfocándose en el ENAM.

Resumo: Objetivo Os oomicetos são um dos grupos parasitários mais difundidos e destrutivos do mundo. A primeira infecção de oomicetos no copépode Parabroteas sarsi Daday 1901 foi recentemente registrada na América. A infecção por Oomycetes nesta espécie torna os seus ovos inviáveis e pode afetar diferentemente a sobrevivência das fêmeas. O objetivo deste estudo foi rastrear a incidência de oomicetos em duas populações de P. sarsi. Métodos Duas poças na patagônia foram monitoradas durante a primavera-verão de 2014-2018, medindo variáveis ambientais e a prevalência de infecções por oomicetos em populações de P. sarsi. A determinação taxonômica dos oomicetos foi realizada em laboratório. As proporções de sexo também foram registradas em cada pesquisa. Resultados A presença de Aphanomyces ovidestruens Gicklhorn 1923 e Pythium flevoense Van der Plaats-Niterink 1972 foi detectada em fêmeas de P. sarsi em ambas as poças. Observamos uma diminuição na prevalência de parasita ao longo do tempo, com uma redução que foi de aproximadamente 25% (considerando o número total de adultos) até próximo de desaparecer completamente. Além disso, uma proporção menor de fêmeas do que de machos foi observada em amostras com alta incidência de parasitismo. Não foram encontradas diferenças de temperatura durante os anos de amostragem e as temperaturas mensais entre as prevalências máxima e mínima foram semelhantes. Conclusão Nosso estudo apresenta um novo registro de parasitismo por oomicetos em copépodes na América. A temperatura pode desempenhar um papel fundamental na dinâmica das espécies parasitárias, mas em nosso estudo esta variável não afetou a incidência da infecção. No entanto, outras variáveis podem afetar o padrão da infecção, como a presença de predadores de esporos de oomicetos (cladóceros). A menor proporção de fêmeas quando a infecção foi maior indicam mortalidade diferencial por sexo induzida pela infecção. O registo e identificação de parasitas é um ponto de partida crítico para a gestão da vida selvagem, o que proporcionará um alerta precoce para prevenir a propagação de parasitas nocivos como os oomicetos.

Abstract: Aim Oomycetes are one of the most widespread and destructive parasitic groups in the world. The first infection of oomycetes on copepod Parabroteas sarsi Daday 1901 was recently recorded in America. Oomycetes infection on this species makes their eggs unviable and could differentially affect the survival of females. The aim of this study was to track the incidence of oomycetes in two populations of P. sarsi. Methods Two Patagonian ponds were monitored during spring-summer of 2014-2018, measuring environmental variables and the prevalence of oomycete infections on P. sarsi populations. Taxonomic determination of the oomycetes was performed in laboratory. Sex ratios also were recorded in each survey. Results The presence of Aphanomyces ovidestruens Gicklhorn 1923 and Pythium flevoense Van der Plaats-Niterink 1972 was detected in females of P. sarsi in both ponds. We observed a decrease in the parasite prevalence over time, from ~25% (assessed on the total number of adults) to almost disappear completely. Besides, a lower proportion of females than males were observed in samples with high prevalence of parasitism. No temperature differences were found during the sampling years and the monthly temperatures between the maximum and minimum prevalences were similar. Conclusions Our study presents a new record of oomycetes parasitizing copepods in America. Temperature can play a key role in the dynamics of parasite species, but in our study this variable not affected the incidence of the infection. However, other variables could be affect the pattern of the infection such as the presence of predators of oomycetes spores (cladocerans). The lower females proportion when the infection was higher, could support the idea of differential sex/mortality induced by the infection. Recording and identification of parasites is a critical starting point for wildlife management, which will provide an early warning to prevent the spread of harmful parasites such as oomycetes.

Resumo Objetivo: Avaliar a associação entre distúrbios do sódio ou do cloro e mortalidade hospitalar de pacientes com insuficiência renal aguda (IRA) ou doença renal crônica (DRC) submetidos a hemodiálise aguda. Métodos: O presente estudo de coorte retrospectiva incluiu pacientes adultos submetidos a hemodiálise aguda com diagnóstico de IRA ou DRC em um hospital público de Lima, Peru. Os distúrbios do sódio foram classificados como hiponatremia (Na < 135mmol/L) ou hipernatremia (Na > 145mmol/L), enquanto os distúrbios do cloro foram classificados como hipocloremia (Cl < 98 mmol/L) ou hipercloremia (Cl > 109mmol/L). O desfecho de interesse foi mortalidade hospitalar. Utilizamos modelos de Poisson da família de modelos lineares generalizados com bootstrap não-paramétrico e correção de viés acelerado para estimar os riscos relativos na análise bruta (RR) e ajustada (RRa) para sexo, idade, HCO3 (para todos os pacientes) e escore de Liaño (apenas para IRA) com IC 95%. Resultados: Foram incluídos 263 pacientes (idade média 54,3 anos; 43% do sexo feminino), 191 com DRC e 72 com IRA. A mortalidade foi mais elevada nos pacientes com IRA (59,7%) do que nos indivíduos com DRC (14,1%). No geral, os pacientes com hipernatremia tiveram mortalidade hospitalar mais elevada do que os indivíduos com valores normais de sódio (RRa: 1,82; IC 95%: 1,17-2,83). Os pacientes com hiponatremia não apresentaram mortalidade diferente (RRa: 0,19; IC 95%: 0,69-2,04). Também identificamos que hipercloremia (RRa: 1,35; IC 95%: 0,83-2,18) e hipocloremia (RRa: 0,66; IC 95%: 0,30-14,78) não elevaram a mortalidade em comparação a indivíduos com níveis normais de cloro. Não foi encontrada associação entre distúrbios do sódio ou do cloro e mortalidade hospitalar nos subgrupos com DRC e IRA. Conclusões: Em nossa análise exploratória, apenas hipernatremia apresentou associação com mortalidade hospitalar em pacientes com IRA ou DRC submetidos a hemodiálise aguda.

Abstract Objective: To evaluate the association between dysnatremias or dyschloremias and mortality during hospitalization in patients with acute kidney injury (AKI) or chronic kidney disease (CKD) undergoing acute hemodialysis. Methods: We carried out a retrospective cohort study on adult patients undergoing acute hemodialysis with AKI or CKD diagnosis at a public hospital in Lima, Peru. Dysnatremias were categorized as hyponatremia (Na < 135mmol/L) or hypernatremia (Na > 145mmol/L), and dyschloremias were defined as hypochloremia (Cl < 98 mmol/L) or hyperchloremia (Cl > 109mmol/L). The outcome of interest was mortality during hospitalization. We performed generalized lineal Poisson family models with bias-corrected and accelerated non-parametric bootstrap to estimate the risk ratios at crude (RR) and adjusted analysis (aRR) by gender, age, HCO3 (for all patients) and Liaño score (only for AKI) with CI95%. Results: We included 263 patients (mean age: 54.3 years, females: 43%): 191 with CKD and 72 with AKI. Mortality was higher in patients with AKI (59.7%) than in patients with CKD (14.1%). In overall, patients with hypernatremia had a higher mortality during hospitalization compared to those who had normal sodium values (aRR: 1.82, 95% CI: 1.17-2.83); patients with hyponatremia did not have different mortality (aRR: 0.19, 95% CI: 0.69-2.04). We also found that hyperchloremia (aRR: 1.35, 95% CI: 0.83-2.18) or hypochloremia (aRR: 0.66, 95% CI: 0.30-14.78) did not increase mortality in comparison to normal chloride values. No association between dysnatremias or dyschloremias and mortality during hospitalization was found in CKD and AKI subgroups. Conclusions: In our exploratory analysis, only hypernatremia was associated with mortality during hospitalization among patients with AKI or CKD undergoing acute hemodialysis.

RESUMEN Introducción: Las consecuencias de la homofobia pueden afectar a la integridad y la salud mental y física de los individuos homosexuales en la sociedad. En Perú hay escasos estudios que hayan evaluado la homofobia en la población médico-estudiantil. Objetivo: Determinar los factores sociales, educativos y culturales asociados con la homofobia entre estudiantes de Medicina peruanos. Métodos: Se realizó un estudio de tipo transversal analítico en 12 sedes de Medicina humana peruanas. Se definió homofobia según un test validado, que se asoció con otras variables. Se obtuvieron estadísticos de asociación. Resultados: Las 4 universidades de Lima obtuvieron menores porcentajes de alumnos homofóbicos (15-20%) que las universidades del interior del país (22-62%). Al realizar el análisis multivariable, disminuyeron la frecuencia de homofobia: ser mujer (RPa = 0,74; IC95%, 0,610,92; p = 0,005), estudiar en una universidad de Lima (RPa = 0,57; IC95%, 0,43-0,75; p < 0,001), profesar la religión católica (RPa = 0,53; IC95%, 0,37-0,76; p < 0,001), conocer a un homosexual (RPa = 0,73; IC95%, 0,60-0,90; p = 0,003) y haber atendido a un paciente homosexual (RPa = 0,76; IC95%, 0,59-0,98; p = 0,036); en cambio, ser machista aumentó la frecuencia de homofobia (RPa = 1,37; IC95%, 1,09-1,72; p = 0,007), ajustado por 4 variables. Conclusiones: La homofobia fue menos frecuente entre las mujeres, los que estudiaban en la capital, los que profesan el catolicismo y los que conocen/han atendido a un homosexual; por el contrario, los machistas fueron más homofóbicos.

ABSTRACT Background: The consequences of homophobia can affect the integrity, mental and physical health of homosexual individuals in society. There are few studies in Peru that have evaluated homophobia in the medical student population. Objective: To establish the social, educational and cultural factors associated with homophobia among Peruvian medical students. Methods: A cross-sectional analytical study was conducted in 12 medicine schools in Peru. Homophobia was defined according to a validated test, which was associated with other variables. Statistical associations were identified. Results: The lowest percentages of homophobic students (15-20%) were found in the four universities in Lima, while universities in the interior of the country had the highest percentages (22-62%). Performing a multivariate analysis, we found that the frequency of homophobia was lower for the following variables: the female gender (PRa=0.74; 95% CI, 0.61-0.92; p=0.005), studying at a university in Lima (PRa=0.57; 95% CI, 0.43-0.75; p<0.001), professing the Catholic religion (PRa=0.53; 95% CI, 0.37-0.76;p<0.001), knowing a homosexual (PRa=0.73; 95% CI, 0.60-0.90; p=0.003) and having treated a homosexual patient (PRa=0.76; 95% CI, 0.59-0.98; p=0.036). In contrast, the frequency of homophobia increased in male chauvinists (PRa=1.37; 95% CI, 1.09-1.72; p=0.007), adjusted by four variables. Conclusions: Homophobia was less common in women, in those who study in the capital, those who profess Catholicism and those who know/have treated a homosexual. In contrast, male chauvinists were more homophobic.

Resumo O artigo analisa o processo de construção das artes marciais mistas (MMA), descreve parte da história do valetudo no Brasil, de sua internacionalização, e identifica as marcas de ruptura entre o valetudo e o MMA. Foram consideradas como características próprias da transição do valetudo para o MMA: a profissionalização da categoria; a aceitação pelos veículos de comunicação; o acirramento do controle do corpo e dos códigos de moralidade no ethos dos lutadores; a criação de um novo produto para o mercado da luta; o deslocamento identitário dos lutadores, de representantes de determinada luta para lutadores de MMA.

Abstract This paper analyses the process of construction of Mixed Martial Arts (MMA). Describes part of the history of "valetudo" in Brazil, its internationalization and identifies the split between "valetudo" and MMA. Own characteristics considered as the transition from "valetudo" to MMA: the professional category; acceptance by media; the tightening of body control and codes of morality in the fighters' ethos; the creation of a new product to fight market; displacement identity of the "valetudo" fighters to MMA fighters.

Resumen El artículo analiza el proceso de construcción de las artes marciales mixtas (MMA). Describe parte de la historia del valetudo en Brasil, de su internacionalización e identifica la diferencia entre el valetudo y las MMA. Se consideraron como características propias de la transición del valetudo para las MMA: la profesionalización de la categoría; la aceptación por parte de los medios de comunicación; el refinamiento del control del cuerpo y del código moral en el ethos de los luchadores; la creación de un nuevo producto para el mercado de la lucha; el cambio identitario de los luchadores, de representantes de determinada lucha a luchadores de MMA.

The main components in milk from cows that are affected by mastitis can be in different amounts according to the racial characteristics. Thus, the association between the somatic cell counts (SCC) and these components may also differ in milk from Jersey cows. This study evaluated the effect of the SCC in milk from Jersey cows on milk production and its physicochemical composition. For 71 months, data from 3244 milking and 300 cows were evaluated considering the effect of the SCC on milk production (kg cow day-1), percentage of fat, protein, lactose, total solids, and nonfat solids. The probable factors associated with fluctuation in milk production based on somatic cell score, lactation number and rainfall were also evaluated by regression models. Milk composition was changed according to the SCC. In general, the higher the SCC in milk, the lower the contents of lactose, fat, and solids, with exception of the protein content, which increased. Losses in milk production of Jersey cows were observed for milk with counts above 50,000 somatic cells per ml.

Los principales componentes de la leche en vacas que tienen mastitis pueden estar en diferentes cantidades de acuerdo con la raza. Por lo tanto, la asociación entre el recuento de células somáticas (RCS) y estos componentes también pueden diferir en la leche de vacas Jersey. Este estudio evaluó el efecto del RCS en leche de vacas Jersey en la productividad y la composición físico-química. Durante 71 meses se evaluaron los datos de 300 vacas y 3 244 ordeños; para ello se consideraron el efecto de RCS en la producción de leche (kg/vaca/día), el porcentaje de grasa, la proteína, la lactosa, los sólidos totales y los sólidos no grasos. Los probables factores asociados con las fluctuaciones en la producción de leche, sobre la base de la puntuación de células somáticas, número de lactaciones y precipitación de lluvia; también se evaluaron por regresión lineal. La composición de la leche estuvo influenciada por el RCS. En general, cuanto mayor fue el número de células somáticas en la leche, menor fue el contenido de lactosa, de grasa y de sólidos, con excepción del contenido de proteínas que se incrementó. Se observaron pérdidas en la producción de leche en vacas Jersey para la leche con recuentos superiores a 50 000 células somáticas/ml.

The aim of this study was to evaluate the subcutaneous tissue response in rats and the antimicrobial activity of intracanal calcium hydroxide dressings mixed with different substances against E. faecalis. Fifty four rats were divided into three experimental groups according to the vehicle in the calcium hydroxide treatment: 0.4% chlorohexidine in propylene glycol (PG), Casearia sylvestris Sw in PG and calcium hydroxide+PG (control group). The pastes were placed into polyethylene tubes and implanted into the subcutaneous tissue. After 7, 14 and 30 days, the samples were processed and histologically evaluated (hematoxylin and eosin). The tissue surface in contact with the material was analyzed, and the quantitative analysis determined the volume density occupied by the inflammatory infiltrate (giant cells, polymorphonuclear cells and mononuclear cells), fibroblasts, collagen fibers and blood vessels. For the antimicrobial analysis, 20 dentin blocks infected with E. faecalis were treated with calcium hydroxide pastes in different vehicles; 0.4% chlorhexidine in PG, PG, extract from Casearia sylvestris Sw in PG and a positive control (infection and without medication) for 7 days. The efficiency of the pastes was evaluated by the live/dead technique and confocal microscopy. The results showed that 0.4% chlorhexidine induced a higher inflammatory response than the other groups. The Casearia sylvestris Sw extract showed satisfactory results in relation to the intensity of the inflammatory response. In the microbiological test, there were no statistical differences between the evaluated intracanal dressings and the percentage of bacterial viability was between 33 and 42%. The control group showed an 86% viability. Antimicrobial components such as chlorhexidine or Casearia sylvestris Sw did not improve the antimicrobial activity against E. faecalis in comparison to the calcium hydroxide+PG treatment. In addition, the incorporation of chlorhexidine in the calcium hydroxide paste promoted the highest inflammatory response.

Objective: To evaluate the response of rat subcutaneous tissue in implanted polyethylene tubes that were filled with GMTA Angelus and Portland cements containing different arsenic concentrations. Material and Methods: Atomic absorption spectrophotometry was utilized to obtain the values of the arsenic concentration in the materials. Thirty-six rats were divided into 3 groups of 12 animals for each experimental period. Each animal received two implants of polyethylene tubes filled with different test cements and the lateral of the tubes was used as a control group. After 15, 30 and 60 days of implantation, the animals were killed and the specimens were prepared for descriptive and morphometric analysis considering: inflammatory cells, collagen fibers, fibroblasts, blood vessels and other components. The results were analyzed utilizing the Kuskal-Wallis test and the Dunn's Multiple test for comparison (p<0.05). Results: The materials showed, according to atomic absorption spectrophotometry, the following doses of arsenic: GMTA Angelus: 5.01 mg/kg, WPC Irajazinho: 0.69 mg/kg, GPC Minetti: 18.46 mg/kg and GPC Votoran: 10.76 mg/kg. In a 60-day periods, all specimens displayed a neoformation of connective tissue with a structure of fibrocellular aspect (capsule). Control groups and MTA Angelus produced the lower amount of inflammatory reaction and GPC Minetti, the highest reaction. Conclusions: There was no direct relationship between the concentration of arsenic present in the composition of the materials and the intensity of the inflammatory reactions. Higher values, as 18.46 mg/kg of arsenic in the cement, produce characteristics of severe inflammation reaction at the 60-day period. The best results were found in MTA angelus.

Objectives: To investigate if there is a relation between the increase of bismuth oxide and the decrease of pH levels and an intensification of toxicity in the Portland cement. Material and Methods: White Portland cement (WPC) was mixed with 0, 15, 20, 30 and 50% bismuth oxide, in weight. For the pH level test, polyethylene tubes were filled with the cements and immersed in Milli-Q water for 15, 30 and 60 days. After each period, the increase of the pH level was assessed. For the biocompatibility, two polyethylene tubes filled with the cements were implanted in ninety albino rats (n=6). The analysis of the intensity of the inflammatory infiltrate was performed after 15, 30 and 60 days. The statistical analysis was performed using the Kruskal-Wallis, Dunn and Friedman tests for the pH level and the Kruskal-Wallis and Dunn tests for the biological analysis (p<0.05). Results: The results showed an increase of the pH level after 15 days, followed by a slight increase after 30 days and a decrease after 60 days. There were no significant statistical differences among the groups (p>0.05). For the inflammatory infiltrates, no significant statistical differences were found among the groups in each period (p>0.05). The 15% WPC showed a significant decrease of the inflammatory infiltrate from 15 to 30 and 60 days (p<0.05). Conclusions: The addition of bismuth oxide into Portland cement did not affect the pH level and the biological response. The concentration of 15% of bismuth oxide resulted in significant reduction in inflammatory response in comparison with the other concentrations evaluated.

Objective To evaluate the biocompatibility and the setting time of Portland cement clinker with or without 2% or 5% calcium sulfate and MTA-CPM. Material and Methods Twenty-four mice (Rattus norvegicus) received subcutaneously polyethylene tubes filled with Portland cement clinker with or without 2% or 5% calcium sulfate and MTA. After 15, 30 and 60 days of implantation, the animals were killed and specimens were prepared for microscopic analysis. For evaluation of the setting time, each material was analyzed using Gilmore needles weighing 113.5 g and 456.5 g, according to the ASTM specification Number C266-08 guideline. Data were analyzed by ANOVA and Tukey's test for setting time and Kruskal-Wallis and Dunn test for biocompatibility at 5% significance level. Results Histologic observation showed no statistically significant difference of biocompatibility (p>0.05) among the materials in the subcutaneous tissues. For the setting time, clinker without calcium sulfate showed the shortest initial and final setting times (6.18 s/21.48 s), followed by clinker with 2% calcium sulfate (9.22 s/25.33 s), clinker with 5% calcium sulfate (10.06 s/42.46 s) and MTA (15.01 s/42.46 s). Conclusions All the tested materials showed biocompatibility and the calcium sulfate absence shortened the initial and final setting times of the white Portland cement clinker.

OBJECTIVES: To compare, in vivo, the accuracy of conventional and digital radiographic methods in determining root canal working length. MATERIAL AND METHODS: Twenty-five maxillary incisor or canine teeth from 22 patients were used in this study. Considering the preoperative radiographs as the baseline, a 25 K file was inserted into the root canal to the point where the Root ZX electronic apex locator indicated the APEX measurement in the screen. From this measurement, 1 mm was subtracted for positioning the file. The radiographic measurements were made using a digital sensor (Digora 1.51) or conventional type-E films, size 2, following the paralleling technique, to determine the distance of the file tip and the radiographic apex. RESULTS: The Student "t" test indicated mean distances of 1.11 mm to conventional and 1.20 mm for the digital method and indicated a significant statistical difference (p<0.05). CONCLUSIONS: The conventional radiographic method was found to be superior to the digital one in determining the working length of the root canal.

OBJECTIVE: This study compared the influence of three epoxy resin-based sealers with distinct radiopacities on the observers' ability to detect root canal filling voids during radiographic analysis. MATERIAL AND METHODS: The root canals of 48 extracted maxillary canines were prepared and divided into three groups. Each group was laterally condensed with one sealer (AH Plus®, Acroseal® or a non-radiopaque sealer), and a longitudinal void was simulated in half of the specimens from each group (n=8). Buccolingual radiographs were obtained and randomly interpreted for voids by a radiologist and an endodontist in a blinded fashion. Teeth were cut and inspected under a microscope to confirm the position of void. Differences in sensitivity and specificity between groups and examiners were compared using the Fisher's Exact and McNemar tests, respectively (α=0.05). RESULTS: Significantly lower sensitivity levels (p<0.05) were observed in the coronal portion of fillings performed with both radiopaque sealers. Specificity values for Acroseal® were significantly higher (p<0.05) in the coronal and apical portions of fillings. CONCLUSIONS: The type of root canal sealer can affect the observers' ability to detect root canal filling voids during radiographic analysis of upper single-rooted teeth.