Biocompatibility of the 8.25% sodium hypochlorite irrigant solution in endodontics: An in vivo study.

The biocompatibility of irrigant solutions, including 8.25% sodium hypochlorite (NaOCl), was analyzed in samples (n = 25) of chorioallantoic membranes (CAM) from embryos of the Gallus gallus, using the hen's egg test on chorioallantoic membrane (HET-CAM). The following irrigants were tested: saline (control), 2% chlorhexidine (2% CHX), and NaOCl (2.5%, 5.25%, and 8.25%), and morphological and microcirculatory changes were investigated. Images were selected and quantified with Image J®. The macroscopic data were submitted to ANOVA, followed by the Tukey's test (p < .05); non-parametric Kruskal-Wallis and Mann-Whitney tests were applied to histological data (p < .05). The frequency of hyperemia differed significantly in the 8.25% NaOCl compared to the other groups, with the exception of 5.25% NaOCl (p = .096). Coagulation was more frequent in the 2% CHX group, differing significantly from the 2.5% NaOCl group (p = .038). In mean values, NaOCl 8.25% caused the decrease (NaOCl = 2.60, and control = 5.00) of vessels in the microcirculation, as well as triggered the increase (NaOCl = 425.50, and control 44.50) of inflammatory cells in the observed areas. There was necrosis in all samples in the 5.25% NaOCl group and in 80% in the 2% CHX, 2.5% NaOCl, and 8.25% NaOCl groups. Fibroblasts were detected only in the control group. It was concluded that the 8.25% NaOCl solution showed significantly high toxicity on CAM. However, these results were comparable to the other concentrations of NaOCl and to 2% CHX. Thus, in this experimental protocol, 8.25% NaOCl proved to be viable as an irrigant solution.

Inequalities in public water supply fluoridation in Brazil: An ecological study.

BACKGROUND: The literature is scarce on the social and geographic inequalities in the access to and implementation of the fluoridation of public water supplies. This study adds knowledge to the Brazilian experience of the chronic privation of water and wastewater policies, access to potable water and fluoridation in the country. Thus, the aim of this study was to verify possible inequalities in the population's access to fluoridated drinking water in 246 Brazilian municipalities. METHODS: The information on the process of water fluoridation in the municipalities and in the macro region in which each municipality is located was obtained from the national epidemiological survey which was concluded in 2003. The data relating to the human development index at municipal level (HDI-M) and access to mains water came from the Brazilian Human Development Atlas, whilst the size of the population was obtained from a governmental source. The Fisher exact test (P < 0.05) was employed to identify significant associations between the explanatory variables and their ability to predict the principal outcomes of interest to this study, namely the presence or absence of the water fluoridation process in the municipalities as well as the length of time during which this measure has been implemented. Linear regression was used to observe the associations between the relevant variables in a multivariate environment. RESULTS: The results clearly showed that there is a relationship between municipalities with larger populations, located in more socio-economically advantaged regions and with better HDI-M, and where fluoridation is both present and has been implemented for a longer period of time (started before 1990). CONCLUSION: The findings suggest that the aim of treating water with fluoride may not be being adequately achieved, requiring more effective strategies so that access to this measure can be expanded equitably.