This study evaluated the antimicrobial activity of the ethanol extract of Annona crassiflora Mart., against the fungus, Candida albicans present in the oral microbiota. The tests showed that the fractions of ethanol extract of the root bark and wood root of A. crassiflora showed a positive result. Of the strains studied, three showed sensitivity to 12 fractions and sub-fractions of A. crassiflora (66%). In the strains studied, strain 05 was the one that proved the most sensitive statistically (p <0.05). Their structures were determined using spectral techniques (NMR 1H and 13C) and based on literature data.

Endodontic infections are polymicrobial and predominantly caused by anaerobic bacteria and some facultative bacteria. The list of microorganisms involved in endodontic infections keeps expanding and has the potential to become increasingly more accurate during the next few years. Copaiba oil is an important Amazonian herbal medicine commercialized worldwide. In this study, we evaluated the antimicrobial activity and minimum inhibitory concentration (MIC) of copaiba oil and substances used in the treatment of endodontic infections against anaerobic microorganisms such as Prevotella melaninogenica; Prevotella intermedia; and Clostridium acetobutylicum. The MIC was determined by thioglycollate broth dilution. The data were statistically analyzed by Tukey's parametric and nonparametric methods of Cochran and Kruskal-Wallis test with a confidence level of 99%. The analysis of the antimicrobial activity showed that the samples of Copaíba oil, Sodium Hypochlorite, Otosporin, Tricresol formalin, Chlorhexidine and PMCC showed high antimicrobial activity (p <0.01). However, different copaiba samples presented different activities. The results reveal Copaíba l sample was the most effective against anaerobic bacteria.

The aim of this study was to evaluate the type of microbiota present in root canals with pulp necrosis, with and without periapical lesion. Nineteen patients were selected for the study and 30 root canals were analysed in unirradicular and/or multi-radicular permanent teeth, asymptomatic, with pulp necrosis, with or without periapical lesion, and no communication between root canal and oral cavity. Absorbent paper cones were introduced in the canal for 20 s. Then, the contaminated paper cones were inoculated in a Brain Heart Infusion Agar-BHI culture medium and incubated in an oven for 48 h at 37°C. The data were analysed by non-parametric statistical method of the Cochran-test. The results revealed that there was no statistically significant difference between the amount of Gram-positive and negative bacteria in endodontic infections, indicating that the microbiota of these endodontic infections is mixed.