Endotoxin in endodontic infections: a review.

Gram-negative bacteria play an essential role in primary endodontic infections. They have several virulence factors such as endotoxin, a large molecule that plays a role in the initiation and perpetuation of apical periodontitis. This paper reviews the role of gram-negative bacteria in endodontic infections, structure and mechanisms of action of endotoxin, endotoxin in infected root canals, effects of calcium hydroxide and polymixin B on endotoxin, and applications of endotoxin to measure leakage.