Objective To establish a quantitative real-time PCR assay for the detection of human cytomegalovirus （HCMV） DNA load in subgingival specimens from the patients with aggressive and chronic periodontitis, and to investigate the relationship between HCMV infection and the periodontal status. Methods A total of 114 subgingival plaque specimens were taken from 18 subjects with aggressive priodontiti（AgP）, 24 subjects with chronic periodontitis （CP） and 15 healthy control subjects. Standard quantification was performed with recombinant plasmid containing a conserved fragment of HCMV. The SYBR Green Ⅰ fluorescent quantitative real-time PCR assay was established based on positive plasmid. HCMV DNA load in the specimens were detected with quantitative real-time PCR based on SYBR Green Ⅰ fluorescence. Results HCMV were detected in 58.3% of AgP sites and 41.7% of CP sites, however, only 6.7% of periodontally-healthy sites were HCMV positive. The detection rate of HCMV in periodontitis lesions was significantly higher than in periodontal health（P＜0.01）. High copy-counts more than 104 of HCMV were detected in 33.3% of AgP sites, which were significantly higher than in CP sites（10.4%）（P＜0.05）. Conclusion Subgingival infection with HCMV is closely associated with periodontitis. Active HCMV infection may be related to the rapid tissue destruction of AgP.
