Figure. An endodontic disease model related to virulence factors of E. faecalis. The virulence factors of the bacterium inside the dentinal tubules and the root canal are released to the periradicular area, where they elicit leukocyte attraction or stimulate leukocytes to produce inflammatory mediators or lytic enzymes. Some of the bacteria may translocate to the periradicular lesion as well. The injurious virulence factors and leukocyte products are shown in the zone between the interrupted lines. In a magnified window, the adhesion of the bacterium to diverse elements of the dentin is depicted. Bacterial products fighting other bacteria are also included. Note that names in black boxes are the products of the bacterium. Abbreviations: Adh, surface adhesins; AS, aggregation substance; Bact, bacteriocins; BS, binding substance; CP, collagen peptides; Cyl, cytolysin; Ef, Enterococcus faecalis; Elas, elastase; Gel, gelatinase; Hya, hyaluronidase; H₂O₂, hydrogen peroxide; IFN-, gamma interferon; IL, interleukin; LE, lysosomal enzymes; LTA, lipoteichoic acid; NO, nitric oxide; O₂^.–, superoxide anion; PGE2, prostaglandin E2; SP, sex pheromones; and TNF, tumor necrosis factor. O₂^.–: The dot denotes the presence of an unpaired electron, and the superscript denotes the negative charge.