Real‐Time Polymerase Chain Reaction to Determine the Prevalence and Copy Number of Epstein‐Barr Virus and Cytomegalovirus DNA in Subgingival Plaque at Individual Healthy and Periodontal Disease Sites

BACKGROUND: Detection of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) in plaque from patients with periodontal disease provides support for the theory that these viruses play a role in the pathogenesis of periodontitis. This study sought to further define this relationship by determining the prevalence of these viruses at individual disease and healthy sites of patients with periodontal disease and to determine whether the presence and amount of viral DNA correlate with disease severity. METHODS: Subgingival plaque from three healthy and three disease sites of 65 patients who had chronic periodontitis were evaluated for the presence and amount of EBV, CMV, and Fusobacterium nucleatum DNA using real-time polymerase chain reaction. Patient serum was evaluated for antibodies against EBV and CMV using enzyme-linked immunosorbent assays. RESULTS: EBV DNA was detected in 18.5% of subgingival plaque samples (72/390) and in at least one of the six plaque samples in 44.6% (29/65) of the patients. CMV DNA was detected in one plaque sample (0.3%). EBV was significantly more prevalent in disease sites (28.2%; 55/195) than in healthy sites (8.7%; 17/195; P = 0.002). However, neither EBV prevalence nor its amount correlated with increased probing depth >5 mm or attachment loss >2 mm, whereas the amount of F. nucleatum DNA did. Sites positive for EBV had a median copy number of eight. Antibodies against EBV and CMV were detected in 85.7% and 78.6% of persons evaluated, respectively. CONCLUSION: EBV was infrequent and CMV was rarely present in individual subgingival sites affected by chronic periodontitis.