Ricardo Carvalhaes Fraga

Antibacterial effects of endodontic irrigants on black-pigmented Gram-negative anaerobes and facultative bacteria

The antibacterial effect of endodontic irrigants was evaluated against four black-pigmented Gram-negative anaerobes and four facultative anaerobic bacteria by means of the agar diffusion test. All solutions used were inhibitory against all bacterial strains tested. A 4% NaOCl solution provided the largest average zone of bacterial inhibition of this study that was significantly superior when compared with the other solutions, except 2.5% NaOCl (p < 0.05). Based on the averages of the diameters of the zones of bacterial growth inhibition, the antibacterial effects of the solutions could be ranked from strongest to weakest as follows: 4% NaOCl; 2.5% NaOCl; 2% chlorhexidine; 0.2% chlorhexidine, EDTA, and citric acid; and 0.5% NaOCl.

In vitro evaluation of antibacterial effects of photo-cured glass ionomer liners and dentin bonding agents during setting

Two dentin bonding agents (Optibond and Syntac), an enamel bonding agent (Heliobond), and two photo-cured glass ionomer cements (Vitremer and Variglass VLC) and their inhibitory effects on bacterial growth during setting were examined. Cultures of eight bacterial species were used to test these materials, except for Vitremer glass ionomer cement, which was tested against only five species. The photo-cured glass ionomer cements and the Syntac dentin bonding system with glutaraldehyde demonstrated a significant inhibitory effect on the growth of several bacteria. Meanwhile, Variglass VLC glass ionomer cement did not exhibit this effect on Lactobacillus casei and Streptococcus sobrinus. Optibond light-cured dentin bonding agent, with fluoride and fillers in its composition, and Heliobond (negative control group) did not demonstrate any inhibitory effect.

Avaliação da dureza de diferentes metais utilizados na confecção de pinos pré-fabricados

Various types of metallic materials are being searched in the last years, suitable for the manufacture of pre-fabricated posts, aiming to be used as Intra root retainers, and aesthetic and functional restoration. You can say that despite some gains in the use of non-metallic materials for the manufacture of intra-root posts, the metal is still a highly reliable alternative, especially because the clinical performance of metal retainers has been excellent. The present study had intended to evaluate in Vickers hardness test, three different metals (C. P. Titanium, Titanium/Vanadium/Aluminum Alloy and Stainless Steel Alloy), that can be used to this end. The results obtained demonstrated significant differences among the three tested materials.