Curcumin-mediated antimicrobial photodynamic therapy reduces the viability and vitality of infected dentin caries microcosms.

BACKGROUND: To our knowledge, there is a lack of evidence on the effect of Antimicrobial Photodynamic Therapy (aPDT) by the application of curcumin against complex biofilms of dental caries lesions. This study aimed to evaluate the viability, vitality, and acid metabolism of infected dentin caries microcosms treated with curcumin-mediated aPDT. METHODS: After microcosm biofilms growing anaerobically on bovine dentin disks immersed in McBain medium with 1% sucrose at 37 °C for 5 days, the biofilms were treated by the association of DMSO water solution or 600 µmol L-1 curcumin with 0, 37.5 or 75 J cm-2 blue LED (455 nm). Then, the colony-forming units (CFU) counts of total microorganisms, total streptococci, mutans streptococci, and total lactobacilli were determined by plating. The lactic acid concentration was analyzed by enzymatic spectrophotometry method, while the vitality of intact biofilms was evaluated by confocal laser scanning microscope (CLSM). Statistical analysis was performed by Kruskal Wallis and post-hoc Dunn's tests (P < 0.05). RESULTS: Curcumin alone did not affect the viability of microorganisms and the vitality of intact biofilms. However, 75 J cm-2 LED alone decreased the total microorganisms and total lactobacilli counts. The combination of curcumin and LED reduced significantly the counts of all microorganism groups and the vitality of intact biofilms. Differences were not observed between the lactic acid concentrations of distinct groups. CONCLUSIONS: Therefore, curcumin-mediated aPDT was effective in reducing the viability and the vitality of infected dentin caries microcosms, without interfering in their acidogenicity.

Preparation and antimicrobial activity of gelatin microparticles containing propolis against oral pathogens.

Gelatin microparticles containing propolis ethanolic extractive solution were prepared by spray-drying technique. Particles with regular morphology, mean diameter ranging of 2.27 microm to 2.48 microm, and good entrapment efficiency for propolis were obtained. The in vitro antimicrobial activity of microparticles was evaluated against microorganisms of oral importance (Enterococcus faecalis, Streptococcus salivarius, Streptococcus sanguinis, Streptococcus mitis, Streptococcus mutans, Streptococcus sobrinus, Candida albicans, and Lactobacillus casei). The utilized techniques were diffusion in agar and determination of minimum inhibitory concentration. The choice of the method to evaluate the antimicrobial activity of microparticles showed be very important. The microparticles displayed activity against all tested strains of similar way to the propolis, showing greater activity against the strains of E. salivarius, S. sanguinis, S. mitis, and C. albicans.