Abstract
The aim of this investigation was to determine the occurrence of the three putative periodontal pathogens P. gingivalis, P. intermedia and A. actinomycetemcomitans in an Arabic population with minimal periodontal disease and no history of exposure to periodontal treatment. Twenty-one subjects from Arabic countries, aged between 22 and 48 years, who had previously not been exposed to any dental care other than extractions and fillings, were selected. The percentage of pockets deeper than 3 mm was 13 per cent and the percentage of sites bleeding upon probing was 62 per cent. Subgingival microbial samples were taken from the deepest pockets. Seventy-eight samples were available for DNA-probe analysis. P. intermedia was present in all individuals, P. gingivalis was identified in 19 subjects, and A. actinomycetemcomitans in six. Eighty-two per cent of all samples were P. intermedia positive, 79 per cent were positive for P. gingivalis and 23 per cent for A. actinomycetemcomitans. A highly significant association was observed between the presence of P. intermedia and P. gingivalis (Fischer's exact test, P<0001). Only 8 per cent of all samples were positive for P. gingivalis but not for P. intermedia, and only 6 per cent were P. intermedia, but not P. gingivalis positive. Furthermore, there was a statistically significant association between A. actinomycetemcomitans and P. gingivalis (P=0.016). All A. actinomycetemcomitans-positive samples were also P. gingivalis positive. This study shows a high frequency of putative periodontal pathogens in an Arabic population with minimal periodontal disease. The finding may be explained by the absence of oral hygiene, minimal exposure to antimicrobial drugs and dental care.