Detection of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in dental plaque samples from children 2 to 12 years of age

The purpose of this study was to detect the presence of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in plaque samples from 104 children, collected from their toothbrushes using a polymerase chain reaction (PCR). The age range of all subjects was 2-12 years. 21, 73 and 10 children with healthy gingiva, gingivitis and periodontitis respectively were selected. Plaque samples were collected from all erupted teeth sites using a sterile toothbrush. The mean concentration of DNA recovered from brushing plaque samples was approximately 660 mu g/ml, which was sufficient for performing a PCR-based survey. Both A. actinomycetemcomitans and P. gingivalis were detected in the primary and mixed dentition. The prevalence of A. actinomycetemcomitans in healthy subjects was 4.8%, and those with gingivitis and periodontitis was 6.8% and 20.0% respectively, while the prevalence of P. gingivalis was 4.8% in healthy subjects, and 9.6% and 20.0% in those with gingivitis and periodontitis, respectively. Our survey, using a toothbrush, indicated that A. actinomycetemcomitans and P. gingivalis are rarely present in oral cavities of healthy children.