A three-dimensional (3D) reconstruction image of the rat alveolar bone showed significant bone resorption in the P. gingivalis OMV-treated rats (OMVs group) compared to the control rats (CTRL group), as well as the rats with chronic periodontitis treated with P. gingivalis OMVs (CP+OMVs group) compared to the untreated rats with chronic periodontitis (CP model group) (Fig. 2B). This evidence concerns the gene CP and periodontitis.