Enterococcus faecalis, a nightmare to endodontist: A systematic review

The main goal in endodontics is the prevention and treatment of diseases of the dental pulp and periapical tissues and it can be best achieved if preventive measures and treatment procedures are based on a thorough and detailed understanding of the etiology and pathogenesis of endodontic diseases. There are some cases in which the treatment has followed the highest technical standards and yet failure results. Scientific evidence indicates microbial factors which play an important role. In most cases, failure of endodontic treatment is a result of microorganisms persisting in the apical portion of the root canal system, even in well-treated teeth. Enterococcus faecalis is recognized as a pathogen in post-treatment endodontic infections and probably the species that can best adapt to and tolerate the ecologically demanding conditions in the filled root canal. Enterococci are also implicated in infections of the root canal system, however, they make up a small proportion of the initial flora which is dominated by Gram negative species. In contrast, it has been reported that enterococci are frequently isolated from obturated root canals of teeth that exhibit chronic periapical pathology. Eradication of E. faecalis from the root canal remains a challenge, while chlorhexidine and combinations of disinfectants show some promise. A better understanding of the role of the virulence factors of E. faecalis in endodontic infections may help in the development of new strategies to prevent or eliminate the infection by this species, thereby improving treatment results in endodontics.