Herpesviral-bacterial co-infection in mandibular third molar pericoronitis

The aim of this study was to assess the presence of herpesviruses and periodontopathic bacteria and to establish their potential association with pericoronitis. Fifty samples obtained with paper points (30 from pericoronitis and 20 controls) were subjected to polymerase chain reaction (PCR) analysis. A single-stage and nested PCR assays were used to detect herpesviruses: human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) and six periodontopathic anaerobic bacteria: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Parvimonas micra, Treponema denticola, and Tannarella forsythia. Pericoronitis samples harbored HCMV and EBV at significantly higher rates than the control group (70 vs. 40 % and 46.7 vs. 15 %, P = 0.035, P = 0.021, respectively). P. micra and T. forsythia (66.7 vs. 0 %, and 40 vs. 10 %, P = 0.001, P = 0.021, respectively) were significantly more common in pericoronitis compared to the control group. Multivariate logistic regression analysis showed that the presence of T. forsythia was associated with pericoronitis development (OR 7.3, 95 % CI, 1.2-43.2, P = 0.028). The occurrence of HCVM and EBV extends our previous knowledge on microbiota in pericoronitis. These PCR-based findings demonstrated that bacterial and viral DNA occurred concomitantly in pericoronitis samples. T. forsythia appeared to be significantly associated with pericoronitis development in the examined sample. Herpesviral-bacterial co-infections might exacerbate the progression of pericoronitis.