In this laboratory study, Fill Canal, Sealapex, MTA and Portland cement presented antimicrobial activity whilst EndoRez did not.

1) Materials tested were not able to prevent contamination over 63 days. 2) Bacterial contamination was verified after 14 and 35 days in the control and experimental groups, respectively. 3) Although materials tested had demonstrated similar sealing capacities, dental implants showed bacterial contamination regardless of their external or internal hexagonal configurations.

Ionomeric materials release different proportions of fluoride and aluminum. Their simultaneous effect on the acidogenicity and composition of S. mutans biofilm is unknown. Six cylindrical specimens of each material (Ketac-fil, Vitremer, Fuji-Ortho LC, F-2000, and Z-100) were incubated with S. mutans GS-5 in culture media containing 5% sucrose (w/v). The media were changed daily for seven days, during which the pH and concentrations of fluoride and aluminum were determined. Furthermore, the concentrations of these ions and insoluble polysaccharide were determined in the biofilm formed at the end of the experimental period. The results showed that all the materials tested released fluoride. However, Vitremer released the highest amount of aluminum and was the most effective in reducing the acidogenicity of S. mutans biofilms. It also significantly affected both biofilm formation and composition. Thus, this study suggests that aluminum released by ionomeric materials may enhance the biological effects of fluoride.

The results of this study highlighted the role of TLR4 in controlling A. actinomycetemcomitans infection.

Engagement of programmed death-1 (PD-1) with its two ligands [programmed death ligand-1 (PD-L1) and PD-L2] has been associated with the suppression of tumor-reactive T cells; however, the underlying mechanism for this T-cell dysfunction is not clear. We hypothesized that PD-1 and PD-L1 signals are, in part, responsible for squamous cell carcinoma (SCC) escape from immune antitumor regulation by modulation of the tumor environment. In the present study, we used a multistage model of SCC to examine the role of PD-1/PD-L1 activation during tumor development. Tumor sites presented an increased percentage of CD4(+) and CD8(+) T cells expressing PD-1 when compared with non-tumorigenic control mice, whereas the expression of PD-L1 was particularly increased in F4/80(+) macrophages in tumor sites. Further, the systemic immune neutralization of PD-1 resulted in a decreased number and delayed incidence rate of papillomas followed by a differential expression of cytokeratins, suggesting that the PD-1-PD-L1 interaction contributes to the progression of SCC by downregulation of antitumor responses. In fact, blocking PD-1 increased the percentage of CD8(+) and CD4(+) T cells, and the levels of interferon-γ in the tumor sites. Our results indicated involvement of PD-1(+) T cells in SCC development and in the modulation of the inflammatory immune response.

No abstract

The antimicrobial activity of substances used as antibacterial agents (solutions of 10% calcium hydroxide, camphorated paramonochlorophenol -PMCC, 2% chlorhexidine digluconate and 10% castor oil plant detergent) on anaerobic bacteria (Fusobacterium nucleatum ATCC 25586, Prevotella nigrescens ATCC 33563, Clostridium perfringens ATCC 13124 and Bacteroides fragilis ATCC 25285), using a broth dilution technique, was evaluated in vitro. For determination of minimum inhibitory and minimum bactericide concentrations (MIC and MBC), two culture broths, Reinforced Clostridial Medium (RCM) and supplemented Brucella, standardized inoculum and serially diluted solutions were used. All antibacterial agents presented antimicrobial activity that varied for different bacteria. There were no differences in the performance of the two broths. Chlorhexidine digluconate was the most effective, with the lowest MICs, followed by castor oil detergent, PMCC and calcium hydroxide. C. perfringens and B. fragilis were the most resistant bacteria to all agents.

No abstract