Figure 1. P. gingivalis invasion of a three-dimensional (3-D) engineered human oral mucoasa model. (A) Structural modifications to the 3-D engineered human oral mucosa model following a P. gingivalis ATCC 33277 infection. (a) Uninfected control model; (b) P. gingivalis ATCC 33277-infected model. Scale bars, 50 µm. (B) Transmission electron micrograph of P. gingivalis in a multilayer of epithelial cells and in the underlying connective tissue of a 3-D engineered human oral mucosa model. These Figs. are from Andrian et al.(2004), and are reprinted with permission.