Cytotoxicity and genotoxicity of natural resin-based experimental endodontic sealers.

OBJECTIVES: The development of endodontic sealers based on natural resins seems to be promising, given their improved biological properties. This study evaluated the cytotoxic and genotoxic effects of two experimental root canal sealers, based on extracts from Copaifera multijuga and Ricinus communis (castor oil polymer), comparing them to synthetic resin-based sealers: a single methacrylate-based, a multi-methacrylate-based, and an epoxy resin-based sealers. MATERIALS AND METHODS: Sealers were prepared, set, and exposed to cell culture medium for 24 h at 37 °C with CO2. V79 cells were exposed to serial dilutions of the extracts of each sealer for 24 h. Cell viability was measured by the MTT assay and genotoxicity was assessed by the formation of micronuclei. RESULTS: The single methacrylate-based sealer had the most cytotoxic effects, with significant reduction in cell viability in all dilutions of the extract. The castor oil polymer-based sealer was, on the other hand, the most biocompatible sealer, with no cytotoxic effects at any concentration. All tested sealers were not genotoxic, excepting the single methacrylate-based sealer. CONCLUSIONS: The tested natural resin-based sealers presented low cytotoxic and no genotoxic effects on cell cultures. CLINICAL RELEVANCE: These results may suggest a good alternative to develop new endodontic sealers, in order to achieve better biological response and healing, when compared to commercially available sealers.

Consumption of school meals provided by PNAE among brazilian public school adolescents / Consumo de comidas escolares proporcionadas por PNAE entre adolescentes de escuelas públicas brasileñas

ABSTRACT Objective: Assess adherence to school food offered by the School Food Program (Programa Nacional de Alimentação Escolar - PNAE) and the associated factors among Brazilian adolescents. Methods: Cross-sectional study with data from the Study of Cardiovascular Risks in Adolescents conducted in 2013-2014, with 58,707 adolescents aged 12 to 17 years-old who attended public schools. Logistic regression models were stratified by sex and the significance level of 5% was adopted for all analyses. Results: There was low adherence to school meals (17.2%). The chance of regular consumption of school meals was higher among male adolescents belonging to the medium (p<0.05) and the low (p<0.05) socioeconomic score categories. For females, the chance of regular consumption of food offered at school was higher among black-skinned, brown-skinned, indigenous-skinned or yellow-skinned adolescents (p<0.05), aged 16 and 17 (p<0.05), who worked (p<0.001) and belonged to the medium (p<0.05) and low (p<0.05) socioeconomic score categories. The regular purchase of food in school cafeterias reduced the chance of regular consumption of school meals for males (p<0.001) and females (p<0.001). Conclusions: Adherence to the food offered by the PNAE is far from ideal, and it is important to create public policies that encourage the consumption of school meals and improve adherence. In addition, the strengthening and drafting of regulations aimed at the sale of food in the interior and surrounding schools' areas is necessary.

RESUMEN Objetivo: Evaluar la adherencia a la comida escolar ofrecida por el Programa Nacional de Alimentación Escolar y los factores asociados entre los adolescentes brasileños. Métodos: Estudio transversal con datos del Estudio de Riesgos Cardiovasculares en Adolescentes realizado en 2013-2014, con 58.707 adolescentes de 12 a 17 años que asistieron a escuelas públicas. Los modelos de regresión logística se realizaron estratificados por sexo, y se aplicó el nivel de significancia del 5% para todos los análisis. Resultados: Hubo baja adherencia a las comidas escolares (17,2%). La posibilidad de consumo regular de comidas escolares fue mayor entre los adolescentes varones pertenecientes a las categorías de puntaje socioeconómico medio (p<0,05) y bajo (p<0,05). Para las mujeres, la probabilidad de consumo regular de alimentos ofrecidos en la escuela fue mayor entre las adolescentes de piel negra, marrón, indígena o amarilla (p<0,05), de 16 y 17 años (p<0,05), quién trabaja (p<0,001) y pertenece a las categorías de puntaje socioeconómico medio (p<0,05) y bajo (p<0,05). La compra regular de alimentos en las cafeterías escolares redujo la posibilidad de consumo regular de comidas escolares para hombres (p<0,001) y mujeres (p<0,001). Conclusiones: La adhesión a los alimentos ofrecidos por el PNAE está lejos de ser ideal, y es importante crear políticas públicas que fomenten el consumo de comidas escolares, mejoren su adherencia, además de ayudar en el fortalecimiento y la redacción de regulaciones dirigidas a la venta de alimentos en el interior y las áreas de las escuelas circundantes.

Setting time affects in vitro biological properties of root canal sealers.

INTRODUCTION: Biocompatibility of root canal sealers is important because of the long-term contact of their eluates and/or degradation products with periapical tissues. The literature still lacks studies about the genotoxic effects of these materials and the influence of setting time on biological properties. The cytotoxicity and genotoxicity of an epoxy resin-based sealer (AH Plus), a single methacrylate-based sealer (EndoRez), and a silicone-based sealer (RoekoSeal) were assessed. METHODS: Chinese hamster fibroblasts (V79) were cultured and exposed to different dilutions of extracts from the sealers that were left to set for 0, 12, and 24 hours before contact with culture medium. Cell viability was measured by the methyl-thiazol-diphenyltetrazolium assay. Genotoxicity was assessed by the comet assay. Data were statistically analyzed by Kruskal-Wallis and Dunn tests (P < .05). RESULTS: Root canal sealers were statistically more cytotoxic than the untreated control group, except for the silicon-based sealer. Cell viability ranking was the following (from the most to the least cytotoxic): methacrylate-based > epoxy resin-based > silicone-based. The setting time influenced the epoxy resin-based sealer cytotoxicity (decreased at 12 hours) and the general genotoxicity (increased at 24 hours). DNA damage ranking was the following (from the most to the least genotoxic): methacrylate-based > silicone-based = epoxy resin-based. CONCLUSIONS: The setting time had influence on the cytotoxicity of the epoxy resin-based sealer and genotoxicity of all tested sealers. The methacrylate-based sealer was the most cytotoxic, and the silicone-based sealer was not cytotoxic. Genotoxicity was observed for all sealers.