The Relationship of Indigenous Bacteria to Periodontal Disease

¹ Forsyth Dental Infirmary and Harvard School of Dental Medicine, Boston, Massachusetts

Summarizing these results, we have demonstrated the presence of several potentially significant metabolites produced by organisms involved in a mixed guinea-pig infection initiated with the microflora of human periodontal disease. These include analogues of vitamin K, which serve as essential nutrients for the maintenance of B. melaninogenicus. They include also a collagenolytic enzyme produced by B. melaninogenicus, an essential component of the mixed infection, and a regular member of the gingival microflora of man. This collagenase is less potent than that of many clostrida, and it is released from the cells at the same time that they undergo lysis. It is suggested that this unusual pattern of collagenase production may be related to the chronic nature of periodontal disease. Also produced by the agents of the guinea-pig infection are desoxyribonuclease and ribonuclease. These agents are probably important in maintaining transmissibility of the mixed infection, and they may facilitate diffusion of bacterial metabolites within the periodontal pocket. Finally, high concentrations of ammonia have been demonstrated in guinea-pig exudate. If similar concentrations are produced in the periodontal pocket, it would be expected that damage to mucous membranes might result.