Green propolis may represent a promising therapeutic alternative against dental anaerobic pathogens because of its antimicrobial action. This study aimed to evaluate the antimicrobial and antibiofilm actions of Brazilian green propolis aqueous extract (BGP-AqExt) against dental anaerobic bacteria. The minimum inhibitory concentration (MIC) and minimum microbicide concentration (MMC) of the extract were determined against the standard strains (ATCC) of Fusobacterium nucleatum, Parvimonas micra, Prevotella intermedia, Porphyromonas gingivalis and Porphyromonas endodontalis. BGP-AqExt was chemically characterized by high-performance liquid chromatography with diode-array detection (HPLC-DAD) analysis. Antibiofilm action was measured by MTT and crystal violet tests. The data were statistically analyzed by ANOVA and Tukey (5%) tests. The extract had antimicrobial action against all tested anaerobic bacteria, with an MIC value of 55 mg/mL for all bacteria, an MMC of 27.5 mg/mL for F. nucleatum and P. micra and 55 mg/mL for P. intermedia. Chemically, BGP-AqExt is composed of quercetin, gallic acid, caffeic and p-coumaric acid, drupani, kaempferol and Artepillin C. Significant reductions in biomass and metabolic action of biofilms were found after BGP-AqExt application. Therefore, BGP-AqExt has an antimicrobial and antibiofilm effect against dental anaerobic bacteria.

The aim of this study was to compare the screw removal torque of mini-conical prosthetic components and straight trunnion of indexed morse taper implants after mechanical cycling. The sample consisted of 40 implants and 20 mini-conical prosthetic components (MC group) and 20 straight trunnion components (ST group). Each group consisted of 10 specimens, with 2 implants in each, and cobalt–chromium metallic crowns were screwed into each sample. The components of the MC group received a torque of 20 N-cm with a digital torque wrench, and after 10 min were retightened with the same value as the initial torque. The components of the ST group received a torque of 30 N-cm, with a digital torque wrench, and after 10 min, they were retightened with the same value. The screws of the respective crowns of the two groups received a torque of 10 N-cm and after 10 min were retightened with the same value. Each group was subjected to the fatigue test in a mechanical cycler at 2,000,000 cycles, with a load of 250 N and frequency of 4 Hz. At the end of the fatigue test, the loosening torque of each screw of the specimens was measured through a digital torque wrench. The data were analyzed by two-way ANOVA and a Tukey test. In both groups, there were loss of torque. The results showed no statistic difference between MC and ST groups (p > 0.05).