Role of spirochaetes and anaerobic bacteria in periodontal disease

Gingivitis is the commonest bacterial inflammaion of the body. 58 patients with different forms of periodontal disease and 10 normal subjects with clinically healthy gingiva were studied. The most important predisposing factors are high carbohydrate diet, bad oral hygiene and smoking. Females tend to be affected more than males especially middle aged. The same bacterial species were isolated from healthy sites, inflamed gingiva or controls. Gingivitis appears to be a redistribution or overgrowth of one bacterial species over the others when predisposing factors exsist. Anaerobic Gram +ve and Gram -ve bacilli especially the group of Beta-melaninogenicus appear to be the most important pathogens. The very rich yield of bacteria and nutritional interdependence of most species were obstacles against isolation of many strains. Antibiotic sensitivity using microbroth technique was done and showed that for this mixed infection it is better to use a combination of tetracycline and clindamycin or metronidazole