Figure 2. Transmission electron micrographs of sections of dentin colonized by S. gordonii. (A) Individual bacterial cells adhering to the wall of a dentinal tubule, with fibrillar surface material visible at the site of association between bacterial cells and tubule. Bar: 0.5 µm. (B) A group of streptococcal cells in intimate contact with a tubule wall. Bar: 1.0 µm. (Reproduced with permission from Love et al., 1997.)