Development of bacterial plaque in the oral cavity.

Dental plaque may be defined as bacterial aggregations upon the teeth and other solid structures inserted in the oral cavity. It is formed by oral microorganisms which attach to the teeth in sheltered areas along the gingival margin, on the approximal surfaces, and in pits and fissures on the masticatory surfaces. The plaque increases in quantity either by multiplication of already attached organisms, or by continuous addition to the deposits of bacteria from the saliva. Structural analyses indicate that the organisms are held together in an exracellular matrix partly produced by the organisms and partly derived from saliva. The microflora of plaque is complex and shows great individual variation. There are also characteristic differences in plaque from different sites on the teeth. Thus dento-gingival plaque is qualitatively different from that of the occlusal fissures. Furthermore, the relative proportion of different types of microorganisms may vary with the age of the deposit. Such information must be taken in consideration when attempts are made to develop chemical agents for the purpose of inhibiting plaque formation in order to prevent periodontal disease and caries.