Therefore, to investigate whether COX-2 expression and nuclear factor kappa B (NF-κB) activation in RAW264.7 cells stimulated by Pg fimbriae can be suppressed by melatonin, it is useful to consider the contribution of melatonin to not only the prevention of oral diseases, but also the regeneration of alveolar bone through stimulation of type I collagen fiber production and modulation of osteoblastic and osteoclastic activity mediated by cellular proteins. Here, PTGS2 is linked to mouth disorder.