Strategies for specific and nonspecific control of human dental plaque development are based on the hypothesis that certain specific species of oral bacteria contribute significantly to oral health or disease. Adherence to salivary pellicle or other bacteria is required for the subsequent colonization of an oral species. The adherence to and prevalence of indigenous oral species on cleaned tooth surfaces, i.e. S. sanguis S. mitis, Actinomyces spp., H. parainfluenzfae, and Veillonella spp., has suggested strongly that these species are among the most predominant species in developing, less than 48 hours, human dental plaques in healthy adults, Specific interbacterial adherence (coaggregation) reactions between these members of developing plaques (and their specific adhesions, lectin-ligand interactions) have been extensively studied in vitro. However, the in vivo role of interbacterial adherence and the specific lectin-ligand binding between different species and genera of bacteria on the rate and composition of dental plaque has not been studied in man. Thus, we propose to (1) compare in vitro an in vivo adherence of predominant oral species to salivary pellicle and to other oral species, (2) measure the rate of accumulation and the presence of indigenous bacteria in supragingival plaque formation on enamel chips placed in the oral cavity. Plaques formed on bare and bacteria-coated surfaces will be compared, (3) compare the effects of various potential antiplaque agents on the rate of development and composition of supragingival plaque and (4) characterize the outer membrane protein containing adhesion(s) from H. parainfluenzae responsible for adherence to experimental salivary pellicle and to S. sanguis. These studies will provide direct qualitative and qualitative result on plaque formation and microbial composition and will provide information enabling investigator to directly test, quantitatively and qualitatively, the effects of specific and nonspecific agents which may be used to control or modify human dental plaque.
