Viruses: are they really culprits for periodontal disease? A critical review.

Periodontal diseases are multifactorial, and many etiological agents are suggested to play a role in their etiopathogenesis. Various risk factors are also suggested to influence the progression of periodontal disease. Until recently, specific bacteria were considered the major pathogens for the disease. However, the occurrence of periodontal disease in some patient groups is still poorly understood, and the role of other initiating agents is being investigated. Evidence strongly suggests the presence of many strains of viruses in the periodontal environment, and possible mechanisms have also been suggested. Periodontal disease as a risk factor for other systemic diseases can also be better explained based on this viral etiology. In this review, we critically analyze the role of viruses in different periodontal diseases, and provide a categorical description of the underlying mechanisms. Clinical implications and future directions are also discussed. Evidence of a causal role of herpes viruses in periodontitis might revolutionize existing strategies to diagnose, prevent, and treat the disease.