Association of human herpesvirus 6 subtypes with symptomatic apical periodontitis

Objective. The occurrence of human herpesvirus (HHV) 6 subtypes A and B in apical periodontitis was determined. The relationship of HHV-6 subtypes to other disease associated herpesviruses, i.e., Epstein-Barr virus (EBV) and human cytomegalovirus, was also investigated. Study design. Forty apical periodontitis samples (17 symptomatic and 23 asymptomatic) and 40 healthy pulp control samples were collected. Nested polymerase chain reaction was used to detect HHV-6 DNA. Results. HHV-6 DNA was observed in significantly higher frequencies in apical periodontitis samples than in control samples (20% vs. 2.5%; P = .03). Further classification of apical lesions revealed that subtype B of HHV-6 was significantly associated with large-sized and symptomatic lesions (P < .01). Thirty-one apical lesions (77%) harbored >= 1 of the tested herpesviruses: EBV was the most frequent herpesvirus (72.5%) in apical periodontitis, followed by HHV-6 (20%). Conclusion. Our findings suggest that EBV and HHV-6B infections can be associated with symptomatic apical periodontitis. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 112:401-406)