Evaluation of the genotoxicity of zinc oxide-eugenol cement to Allium cepa L / Avaliação da genotoxicidade do cimento de óxido de zinco e eugenol em Allium cepa L

Dental materials can induce local and systemic effects. The Allium cepa assay was used to evaluate the genotoxicity and/or cytotoxicity of zinc oxide and eugenol (ZOE) at different proportions. The ZOE solution was tested at the concentration of 1 drop of eugenol (in each drop of liquid, the approximate concentration of eugenol is 85%) and 1 portion of zinc oxide cement (treatment I), and twice the concentration of eugenol (treatment II) . Treated roots appeared to be yellowish-brown, fewer in number, thicker and less turgid compared with the control, suggesting a cytotoxic activity of ZOE. A significant difference was found in the root size between the control and treatment II. This treatment reduced by 79% the size of the root compared with the control, and the mitotic index was 66%, indicating a 22.4% reduction relative to the control, which in turn evidenced the cytotoxicity of ZOE. The significant increase in anaphase bridges suggests a genotoxic effect.

Materiais dentários podem induzir diversos efeitos, tanto local quanto sistêmico. Objetivou-se avaliar a ocorrência de danos genéticos e de alterações nucleares degenerativas indicativas de genotoxicidade e citotoxicidade em células de cebola em mitose, expostas a óxido de zinco e eugenol (ZOE) em diferentes proporções. Os bulbos foram postos a germinar, com a parte inferior mergulhada na solução de ZOE + água destilada. A solução de ZOE foi testada na concentração de uma gota de eugenol (aproximadamente 85%) e 1 porção do cimento de óxido de zinco (tratamento I) e o dobro da concentração do eugenol (tratamento II). As raízes do controle apresentaram coloração esbranquiçada e eram túrgidas, enquanto as raízes dos tratamentos se mostraram de cor amarela ­ amarronzada, em menor quantidade, mais grossas e menos túrgidas, sugerindo ação citotóxica de ZOE. Houve diferença significativa do tamanho das raízes entre o controle e o tratamento II. O tratamento II reduziu 79% do tamanho da raiz e o índice mitótico foi 66%. Isto mostra redução de 22,4% quando comparado com o controle, evidenciando a ação citotóxica de ZOE. O aumento significante de pontes anafásicas sugere efeito genotóxico.

Nuclear anomalies in the buccal cells of calcite factory workers

The micronucleus (MN) assay on exfoliated buccal cells is a useful and minimally invasive method for monitoring genetic damage in humans. To determine the genotoxic effects of calcite dust that forms during processing, MN assay was carried out in exfoliated buccal cells of 50 (25 smokers and 25 non-smokers) calcite factory workers and 50 (25 smokers and 25 non-smokers) age- and sex-matched control subjects. Frequencies of nuclear abnormalities (NA) other than micronuclei, such as binucleates, karyorrhexis, karyolysis and 'broken eggs', were also evaluated. Micronuclei and the other aforementioned anomalies were analysed by two way analysis of covariance. The linear correlations between the types of micronucleus and nuclear abnormalities were determined by Spearman's Rho. There was a positive correlation between micronuclei and other types of nuclear abnormalities in accordance with the Spearman's Rho test. Results showed statistically significant difference between calcite fabric workers and control groups. MN and NA frequencies in calcite fabric workers were significantly higher than those in control groups (p < 0.05). The results of this study indicate that calcite fabric workers are under risk of significant cytogenetic damage.