Distinctive features of the microbiota associated with different forms of apical periodontitis

Microorganisms infecting the dental root canal system play an unequivocal role as causative agents of apical periodontitis. Although fungi, archaea, and viruses have been found in association with some forms of apical periodontitis, bacteria are the main microbial etiologic agents of this disease. Bacteria colonizing the root canal are usually organized in communities similar to biofilm structures. Culture and molecular biology technologies have demonstrated that the endodontic bacterial communities vary in species richness and abundance depending on the different types of infection and different forms of apical periodontitis. This review paper highlights the distinctive features of the endodontic microbiota associated with diverse clinical conditions

Biofilm biomass disruption by natural substances with potential for endodontic use

This study evaluated the in vitro effects of four natural substances on the biomass of bacterial biofilms to assess their potential use as root canal irrigants. The following substances and their combinations were tested: 0.2% farnesol; 5% xylitol; 20% xylitol; 0.2% farnesol and 5% xylitol; 0.2% farnesol, 5% xylitol, and 0.1% lactoferrin; 5% xylitol and 0.1% lactoferrin; and 20 mM salicylic acid. The crystal violet assay was used to evaluate the effects of these substances on the biomass of biofilms formed by Enterococcus faecalis and Staphylococcus epidermidis. All substances except for 20 mM salicylic acid and 20% xylitol reduced biofilm mass when compared to controls. The combination of farnesol and xylitol was the most effective agent against E. faecalis ATCC 29212 (p < 0.05). Farnesol combined with xylitol and lactoferrin was the most effective against biofilms of the endodontic strain of E. faecalis MB35 (p < 0.05). Similarly, combinations involving farnesol, xylitol, and lactoferrin reduced the biomass of S. epidermidis biofilms. In general, farnesol, xylitol, and lactoferrin or farnesol and xylitol reduced biofilm biomass most effectively. Therefore, it was concluded that combinations of antibiofilm substances have potential use in endodontic treatment to combat biofilms