Fungi in endodontic infections.

Fungi are chemoorganotroph eukaryotic microorganisms that can take part in endodontic infections and thereby may participate in the etiology of periradicular diseases. They possess virulence attributes--including adaptability to a variety of environmental conditions, adhesion to a variety of surfaces, the production of hydrolytic enzymes, morphologic transition, biofilm formation, and evasion and immunomodulation of the host defense--that may play a role in the pathogenesis of periradicular diseases. Fungi have occasionally been found in primary root canal infections, but they seem to occur more often in the root canals of obturated teeth in which treatment has failed. Candida albicans is by far the fungal species most commonly isolated from infected root canals, and this species has been considered a dentinophilic microorganism because of its invasive affinity to dentin. C albicans has also been discovered to be resistant to some intracanal medicaments, such as calcium hydroxide. Its ability to invade dentinal tubules and resistance to commonly used intracanal medicaments may help to explain why C albicans has been associated with cases of persistent root canal infections. Some medicaments, such as chlorhexidine digluconate, calcium hydroxide combinations (with camphorated paramonochlorophenol or chlorhexidine), and EDTA, have the potential to be used as effective intracanal medications for patients in whom fungal infection is suspected.