| the natural history of periodontal disease. the correlation of selected microbiological parameters with disease severity in sri lankan tea workers. | the purpose of this study was to assess the prevalence of a. actinomycetemcomitans, porphyromonas gingivalis and prevotella intermedia, and their association with periodontal disease states in a population sample from sri lanka. based on clinical parameters, a total of 536 sites in 268 male sri lankan tea workers were categorized as healthy, or showing gingivitis only, moderate or advanced periodontitis. bacterial samples were obtained from all sites and the three target bacteria identified by i ... | 1995 | 7593696 |