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.
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 % ).
Our findings suggest that EBV and HHV-6B infections can be associated with symptomatic apical periodontitis.