Abstract
Human cytomegalovirus (HCMV), a herpesvirus, is discussed in this review as it relates to destructive periodontal disease in humans. HCMV genomic sequences, detected by polymerase chain reaction identification, occur with elevated frequency in severe adult periodontitis, localized and generalized aggressive (juvenile) periodontitis, Papillon-Lefèvre syndrome periodontitis, acute necrotizing ulcerative gingivitis, and periodontal abscesses. Herpesviruses establish lifelong persistent infections. HCMV infection involves an asymptomatic latent phase interrupted by periods of recrudescence where viral replication and possibly clinical disease become manifest. HCMV reactivation is triggered by a number of immunosuppressive factors, some of which have been shown also to be risk factors/indicators of periodontitis. HCMV periodontal infection may cause release of tissue-destructive cytokines, overgrowth of pathogenic periodontal bacteria, and initiation of cytotoxic or immunopathologic events. A growing body of data supports the concept that HCMV contributes to severe types of periodontal disease. HCMV infection of the periodontium may alter the immune control of resident microorganisms and be important in a multistage pathogenesis of periodontitis involving viral activation, periodontopathic bacteria, and host immune responses. Understanding the significance of HCMV and other herpesviruses in the development of periodontal disease may have important therapeutic implications. Vaccines against HCMV, which are in various stages of development, need to be evaluated for their ability to decrease the incidence of destructive periodontal disease.