Association between human herpesviruses and the severity of periodontitis

Background: Herpesviruses may play roles in the development of periodontal diseases. The present study evaluated the relationships between herpesviruses and the severity of periodontitis. Methods: Periodontal status in terms of gingival inflammation, bleeding on probing, probing depth, and clinical attachment loss of 20 participants was evaluated. The presence of herpes simplex virus (HSV), human cytomegalovirus (HCMV), or Epstein-Barr virus type 1 (EBV-1) in six subgingival plaques from each participant was examined by nested-polymerase chain reaction techniques. Results: Among the 120 sites examined, the prevalence of HCMV (51.7%) was higher than HSV (30.8%) followed by EBV-1 (4.2%). The prevalence of HSV or HCMV was significantly higher in the subgroups that had lower plaque index (<1). However, the prevalence of HSV was significantly higher in the subgroup that had higher gingival index (≥2), positive bleeding on probing, deeper probing depth (≥4 mm), or higher clinical attachment loss (≥4 mm). Moreover, the prevalence of EBV-1 was significantly higher in the subgroup that had higher probing depth (≥4 mm). Coinfection of HSV and HCMV was significantly associated with the sites that had higher gingival index (≥2) or positive bleeding on probing. Coinfection of any two herpesviruses was also associated with higher probing depth (≥4 mm) or higher clinical attachment loss (≥4 mm). Conclusions: This study demonstrated that HSV is related to the severity of periodontal diseases in terms of clinical attachment loss. Coinfection of any two herpesviruses may also play roles.