Inflammation comprises a series of events that leads to a host response against trauma and microbial invasion, resulting in liquefaction of surrounding tissues to prevent microbial metastasis, and eventually to healing of injured tissue compartments. Thus, by definition, the host response involves not only the mechanisms of defence but also processes of repair of damage that occurs by the direct effect of invaders or trauma or host systems. Periodontal diseases are inflammatory processes in which microbial etiologic factors induce a series of host responses that mediate an inflammatory cascade of events in an attempt to protect and heal the periodontal tissues. The adjunctive use of host modulation therapy can enhance therapeutic responses,...