The oral cavity is similar to an ecosystem that is populated by physiologically distinct microorganisms which successfully live together and thrive by continually adapting and coordinately responding to other organisms in their local environment, to nutrient flux, and to other environmental stresses. For survival, oral organisms may express sophisticated intraspecies and/or interspecies communication mechanisms that facilitate a coordinated response by members of the microbial community to environmental flux. This review paper details the bacterial communicating signaling pathways, the impact that they have on regulating gene expression and its applied aspects.