Herpes virus: A key missing piece of the periodontopathogenic jigsaw puzzle

A solid understanding of the etiology of periodontitis is critical for developing therapies that can ensure long-lasting disease control. Research during the past 15 years has implied that herpes viruses are involved in the etiopathogeny of destructive periodontal disease. Because of the high copy counts of Epstein-Barr virus and cytomegalovirus in aggressive and chronic periodontitis, it is unlikely that these pathogenic viruses are acting merely as innocuous bystanders present in proportion to the severity of the underlying periodontal pathosis. However, herpes viruses are probably not stand-alone periodontopathic agents but cooperate with specific bacteria in periodontal tissue breakdown. A coinfection of active herpes viruses and periodontopathic bacteria may constitute a major cause of periodontitis and explain a number of the clinical characteristics of the disease. The purpose of this review is to evaluate the evidence supporting the hypothesis that viral infection plays a role in the development of periodontitis.