This proposal extends our previous work during the first 24 months of the R23 project on the acquisition of periodontal microorganisms in the newborn and maturing primate Macaca fascicularis, and our initial studies on mother-infant transmission of specific microorganisms know to be involved in periodontal disease. We have established a primate colony of M. fascicularis mother-infant pairs to study under rigidly controlled conditions the acquisition of the periodontal microbiota as a function of somatic maturation and tooth development. The results during these 24 months suggest that key bacterial species thought to be of periodontopathic potential ate acquired during the first year of the primate's life during the establishment of the primary dentition. The present grant proposal will seek to extend these initial observations to studies directed at the manipulation of the maternal microbiota by more intensive alteration of the subgingival plaque so as to determine if acquisition of specific Gram- negative bacteria associated with periodontal disease can be altered in the young primate by manipulation of the maternal bacterial load. Observations made in humans and monkeys that the immature primate is more resistant to conversion of gingivitis to periodontitis upon tooth ligation in the developing primate. It is therefore the goal of this grant period to extend further our understanding of the acquisition of Gram-negative bacteria in the gingival crevice as a function of maturation of the primate from birth to adulthood in relation to the development of periodontal disease. The objectives of the present grant period are: 1. To ascertain the influence of the maternal subgingival by altering the maternal microbiota; 2. to study longitudinally the oral microbiota and associated serum antibody titers of the newborn primate from birth to puberty; and 3. To determine the age-related effects on development of gingivitis and periodontitis from puberty to young adulthood in primates who's somatic and dental development has been studied since birth, with known oral, clinical, microbiological, and immunological parameters.